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Hello, i will attach the data with the lab format and the lab manual to do lab 6

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WIDENER UNIVERSITY DEPARTMENT OF CIVIL ENGINEERING CE 206 STRUCTURES AND MATERIALS LABORATORY MANUAL Spring 2018 Contents I. LABORATORY FORMAT ............................................................................................ 4 A. COURSE OBJECTIVES ..................................................................................... 4 B. CLASS ORGANIZATION .................................................................................. 4 C. LABORATORY ORGANIZATION ................................................................... 4 D. LABORATORY REPORT FORMAT ................................................................ 5 E. EXECUTIVE SUMMARY FORMAT ................................................................ 9 F. DESIGN-BUILD-TEST PROJECT: ..................................................................... 10 II. LABORATORY POLICIES ....................................................................................... 12 III. Technical Writing Assignent: Review of Journal Article ......................................... 13 A. Objectives: .......................................................................................................... 13 B. References: ......................................................................................................... 13 C. Background: ....................................................................................................... 13 D. Procedure:........................................................................................................... 13 IV. Lab #1 Concrete Mix Design and Compression Tests .............................................. 17 A. Objectives: .......................................................................................................... 17 B. References: ......................................................................................................... 17 C. Background: ....................................................................................................... 17 D. Materials: ............................................................................................................ 20 E. Equipment: ......................................................................................................... 20 F. Procedure: .............................................................................................................. 20 G. Calculations: ....................................................................................................... 22 V. Lab # 2: Measuring Tensile Properties of Metal Specimens ...................................... 24 A. Objectives: .......................................................................................................... 24 B. References: ......................................................................................................... 24 C. Background: ....................................................................................................... 24 D. Specimens: ......................................................................................................... 27 E. Equipment: ......................................................................................................... 27 F. Testing Procedure: ................................................................................................. 27 G. Measurements and Calculations:........................................................................ 28 VI. Lab #3 Measuring Forces in Truss Members Using Strain Gages ........................... 30 A. Objectives: .......................................................................................................... 30 B. References: ......................................................................................................... 30 C. Background: ....................................................................................................... 30 D. Specimens: ......................................................................................................... 31 E. Equipment: ......................................................................................................... 31 F. Procedure: .............................................................................................................. 31 G. Calculations: ....................................................................................................... 32 VII. Lab #4 Wooden Beam Tests ..................................................................................... 33 A. Objectives: .......................................................................................................... 33 B. References: ......................................................................................................... 33 C. Background: ....................................................................................................... 33 D. Materials: ............................................................................................................ 34 2 E. Equipment: ......................................................................................................... 34 F. Procedure:........................................................................................................... 34 G. Calculations: ....................................................................................................... 34 IX. Lab # 5 Beam Stresses and Deflections ..................................................................... 41 A. Objectives: .......................................................................................................... 41 B. References: ......................................................................................................... 41 C. Background: ....................................................................................................... 41 D. Specimens: ......................................................................................................... 42 E. Equipment: ......................................................................................................... 42 F. Procedure: .............................................................................................................. 42 G. Calculations: ....................................................................................................... 43 X. Lab #6 Hot Mix Asphalt Superpave Volumetric Design and Compaction Tests ........ 45 A. Objectives: .......................................................................................................... 45 B. References: ......................................................................................................... 45 C. Background: ....................................................................................................... 45 D. Materials: ............................................................................................................ 47 E. Equipment: ......................................................................................................... 47 F. Procedure: (based on AASHTO T166 Test Method A) .................................... 47 G. Measurements and Calculations:........................................................................ 48 3 I. LABORATORY FORMAT A. COURSE OBJECTIVES The Structures and Materials Laboratory is intended to (1) supplement theoretical knowledge in CE structures and construction materials; (2) acquaint students with basic measurement and experimental techniques to examine properties of materials and structural components; (3) develop the ability for planning and design of projects; (4) familiarize the student with basic statistics for analysis of experimental data; (5) develop written and oral communication skills; and (6) provide exposure to the interpersonal relationships involved in group work. Upon successful completion of the course, students will be able to: 1. Conduct experiments to measure properties of materials and systems for civil engineering applications. 2. Analyze data for error analyses, comparison of experimental and theoretical results, and application of regression analyses. 3. Prepare engineering laboratory reports using appropriate technical writing methods. 4. Design, conduct, and present an independent project. B. CLASS ORGANIZATION 1. The class will be divided into lab teams to perform the experimental work, but each student is required to submit an individual lab report or executive summary for each experiment, with the exception of the design-build-test project when a single group report from the project team is submitted. 2. Detailed instructions for the prepared experiments are included in this manual. Students are expected to be familiar with the objectives, scope, and content of the lab prior to the experiment. Some labs may require preliminary calculations (truss analyses for example), and these calculations should be prepared prior to the lab. Deviations from the lab manual will be discussed by the instructor prior to the lab. 3. Safety policies are posted in each laboratory and in this manual (see Laboratory Policies). Students are expected to comply with these policies at all times. Failure to comply with these policies will result in reductions of lab grades and possibly dismissal from the lab. C. LABORATORY ORGANIZATION 1. A schedule of lab experiments will be provided for the semester. The instructor will discuss objectives and procedures for each experiment during the weekly 4 lecture period. Each student is expected to read and be familiar with the objectives, background, and procedures for each week’s lab prior to lecture. 2. All students are required to be present for, and participate in, the experimental work done in the laboratory. All excused absences require a written request in advance and/or proper corroboration such as a physician's note. Unexcused absences cannot be made up and will result in the student receiving a zero for the lab. 3. All students are expected to participate and contribute to the success of each lab experiment. Tasks should be coordinated within each group and should include setting of lab equipment, making preliminary calculations and quality assurance checks, obtaining measurements and recording data. It is the responsibility of the entire team to ensure that the best results are obtained. 4. One set of data should be recorded per group. The responsibility of data recorder should rotate. At the completion of the lab, the instructor will post the data sheets or a compilation of the data for all group members on shared files. These data sheets should be attached in the appendix of all lab reports. It is extremely important to clearly and accurately record all data. D. LABORATORY REPORT FORMAT 1. Lab reports and executive summaries should be written from the perspective of a practicing engineer to the extent possible. The reports should be written for a general technical audience (such as another engineering student or faculty). Assume that the assignments are projects that you are assigned to work on by your project manager or client. Therefore, phrases such as: “the students were given the test specimens ….,” should be avoided. In addition, the stated objectives of the lab should be technical objectives, not “educational objectives.” For instance, a practicing engineer is not likely to tell his client that he did the work to learn how to use the equipment. 2. All reports should be prepared using Microsoft Word and submitted through the assignment tab in Campus Cruiser. Assignments are due at the start of the class. Students will be responsible for maintaining copies of all reports in the event that a file is lost or revisions are necessary. 3. All text should be double spaced. Margins (at least one-inch) should be provided on all sides of the page. Pages should be consecutively numbered beginning with page 1 following the title page. 4. All Tables and Figures must be properly numbered (Figure 1, Table 1), titled, and labeled (including units), and they should appear as soon as possible after they are referred to in the text. For figures (graphs, sketches, pictures, or other illustrations), the figure number and title appear at the bottom of the figure. Table 5 numbers and titles appear at the top of each table. Original data records and sample calculations DO NOT belong in the body of the report, but should be included in titled appendices. The results should be presented in tabular/graphical format, and must include all data and information so the reader can check the work. 5. All equations must be sequentially numbered (ie. Eq. 1), and all variables in the equation must be identified the first time they appear in the report. 6. Avoid the use of personal pronouns such as “we” or “I”. Although these pronouns are perfectly acceptable in other writing styles, they are not widely accepted by technical journals in science and engineering. Science and engineering journals prefer an objective viewpoint; the work being described should be reproducible by anybody following the procedures described in the study. The use of “we” and “I” is subjective and may imply that only the authors could do the work. In recent years it has become more acceptable to use “we,” especially in situations where the author is discussing or interpreting (such as in the introduction or conclusion sections); however it is still good practice to avoid “we” whenever possible (for example, write “Four cylinders from each batch of concrete were tested” instead of “we tested four cylinders from each batch of concrete”. 6. Avoid the use of colloquialisms, jargon, and meaningless or unnecessary phrases (ie. - "the results were as expected", or "this was a good experiment"). All parts of the lab report should directly support the objectives of the lab. 7. Use proper spelling and grammar - points will be deducted from lab reports if grammar and spelling errors persist. Help from the University Writing Center should be considered, or may be required, if writing problems are not corrected. References will be made available for help with technical writing. 8. Sections and Content of the Lab Reports: Students should view their lab report as the final product of their work, or their “deliverable,” similar to the way a practicing engineer views the report he or she submits to a client. Lab reports will be organized in the following sections: a. Title Page b. Table of Contents c. Abstract: The abstract is a brief one to two-paragraph summary of the objectives, work conducted during the experiment, and significant results or findings. Sometimes a background statement may be provided at the beginning of the abstract. The abstract allows the reader to determine the nature and scope of the report without having to read from beginning to end. The optimal length is one paragraph, but it could be as short as two sentences. The length of the abstract depends on the subject matter and the length of the paper. Between 80 and 200 words is usually adequate. 6 d. o o o Introduction: Background statement on the relevance of the lab from an engineering perspective; technical objectives of the lab; overview, or scope of work describing the major tasks or activities completed in the lab. If the introduction is not logical, then your reader will assume that the rest of the document is garbage. A good introduction is a clear statement of the problem or project and the reasons that you are studying it. This information should be contained in the first few sentences. Give a concise and appropriate discussion of the problem and the significance, scope, and limits of your work. The Introduction can be structured something like this: Context: Connect the lab you are doing to real world applications to show that you understand the problem and its relevance from an engineering perspective Problem Description: Give a brief description of what you were required to do in the lab - an overview, or scope, of the work. Goals: Discuss the technical objectives. What were you trying to accomplish? e. Background: Provide any information necessary for the reader to understand subsequent sections of the report. Sometimes the Background section is combined with the Introduction; in other reports, the Background section may be used to explain the underlying theoretical basis for later calculations. f. Methods and Procedures: This section often consists of two parts: 1. Experimental Procedures: procedures performed to acquire data, 2. Analytical Procedures: methods applied to analyze the data to produce the results and achieve the objectives. This section can also be called “Experimental Methods” or “Materials and Methods”. The Experimental Procedures subsection should provide a general description of the equipment used and the work conducted during the experiment, with particular attention to any deviations from the lab manual. This section is not a repeat of the step by step set of instructions that are found in the lab manual! For experimental work, give sufficient detail about your materials and methods (both experimental procedures and methods of data analysis) so that other experienced workers can repeat your work and obtain comparable results. When using a standard method, cite the appropriate literature and give only the details needed. Identify the test specimens/materials and equipment/apparatus used for the laboratory work. Describe equipment/apparatus only if it is not standard or not commercially available. Giving a company name and model number in parentheses is nondistracting and adequate to identify standard equipment. If the laboratory work will also involve calculations using theoretical equations, then the “Methods” portion of the Procedure can be broken into two subsections – one to cover “Experimental Procedures” and one to describe “Analytical Procedures” or “Theoretical Calculations.” The “Analytical Procedures” subsection should include sufficient mathematical detail to enable other researchers to 7 reproduce derivations and verify numerical results. Include all equations and formulas necessary, but lengthy derivations are best presented in the Appendix. Many students fail to recognize that the equations and statistical methods applied to obtain the results are as important as the raw data. The reader expects to see these methods discussed BEFORE the results are presented. After reading these details in the Procedures and Methods Section (or in the Background), the reader will know what to look for and expect in the Results and Discussion Section. Students may wish to use subheadings, such as Experimental Procedures and Analytical Procedures, to help write and organize this section. The Analytical Procedures subsection should present and discuss the theories, formulas, and equations that are applied to the data, or otherwise examined during the experiment. Equations should be numbered and all symbols or parameters in the equation should be identified as you would find in a technical journal article. g. Results and Discussion: This is where you detail the results you obtained in the laboratory. Summarize the data collected and their statistical treatment. Include only relevant data, but give sufficient detail to justify your conclusions. Tables and graphs should be used where necessary to present your data, calculations, and results. Remember that all figures and charts must be accompanied by supporting text. Discussion must be provided to describe and explain the data and the significance of the information in the tables and graphs. The purpose of the discussion is to interpret and compare the results. Be objective; point out the features and limitations of the work. Relate your results to current knowledge in the field and to your objectives for the project. Comparison of results with theory or accepted formulas should be discussed. Sources of error should be discussed with respect to your findings and the significance of these errors with respect to the objectives of the lab. The Results and Discussion section usually follows the following format: introduce a table, figure, or written results (Table 1 shows the material properties found from the tensile tests), present the table, figure, or results (Table 1 is inserted into the report), and finally discuss the table, figure, or written results (write about the information that is included in Table 1). Only then is the next set of data (table or figure) introduced, presented, and discussed. The section should begin with overall results presented first, followed by more detailed results or comparisons. h. Conclusions: Summarize objectives, significant results, and discuss conclusions and recommendations as they relate to your objectives. This is where you should document the "lessons learned" during the course of the laboratory exercise. What were your expected results? Were those results achieved? If not, why not? Have you resolved the problem? What exactly have you contributed? Briefly state the logical implications of your results. Suggest further study or applications if warranted. If you were allowed different constraints in the laboratory could you have designed a better, faster, or cheaper system? If so, how? 8 i. References: Provide a bibliographic list of references used in the lab report. Document the reference sources you used. That way, if you ever need to find the information again, you'll have a head start on finding it. Use a standard method of citation. A commonly accepted method is the MLA, given in MLA handbook for writers of research papers, 6th ed, 2003. New York: The Modern Language Association of America. You can find it in Wolfram Library. Call Number: M Desk Reference Z253 .C534 j. Appendix: original data sheets from lab, derivations, calculations (at least one complete set of sample calculations must be included with each report), and any other related information which supports the lab report, but does not fit in the main report. E. EXECUTIVE SUMMARY FORMAT The executive summary is a standalone section in a formal report that provides a shortened version of the report and summarizes the key facts and conclusions contained in the report. Sometimes the executive summary is filed separately from the formal report. We will be using a modified form of the executive summary as the report you will turn in for some of the experiments we do this semester. Which experiments require full lab reports and which require executive summaries is shown on the syllabus. Your executive summaries will be “modified” in that you must provide a full discussion of the results and also include an appendix with all data sheets and appropriate calculations. Your executive summary will be similar to the requirements for the lab reports but will leave out the abstract, table of contents, background, and methods and procedures sections from the report. Your executive summary should NOT contain separate sections as is done in the lab report. Instead, it should be written in paragraph format with each section starting in a new paragraph. The executive summary shall contain: a. Title Page b. Background Statement: The background statement (also called the context) connects the lab to real world applications to show you understand the problem and its relevance from an engineering perspective. c. Objectives: A statement of what you are trying to accomplish. Similar to the objectives in a lab report, this section should only contain the technical objectives. d. Scope of Work: A brief description of what you were required to do in the lab. Include general processes but not the details. For example, you should state that strain gage data was collected but you don’t need to provide details about where the strain gages were located or how the data was collected. e. Results and Discussion: This is where you introduce, present and describe the results you obtained in the laboratory. Summarize the data collected and the analysis that is done with that data, giving sufficient detail to justify your conclusions. As in the Results and Discussion section of the full laboratory report, tables and graphs are to be used where necessary to present your 9 data, calculations, and results. Remember that discussion must be provided to describe and explain the data and the significance of the information in the tables and graphs. The purpose of the discussion is to interpret and compare the results. Point out the features and limitation of your work and relate your results to the technical objectives of the lab. Compare your results with theory or accepted formulas and discuss the comparison. Sources of error should be discussed with respect to your findings and the significance of the errors with respect to the objectives of the lab. The Results and Discussion section will follow the same format that was used in the lab report format. f. Conclusions: Unlike in the full lab report, in the executive summary’s conclusions you do NOT repeat the objectives or significant results, as the information was presented in earlier paragraphs of the executive summary. This is where you should write about the “lessons learned” from the laboratory. What were your expected results? Were those results achieved? If not, why not? Have you resolved the problem? Briefly state the logical implications of your results. Suggest further study or applications if appropriate. If you had different constraints in the laboratory, could you have gotten better results? If so, how? g. Appendix: While a typical executive summary would not include an appendix, you are required to submit the original data sheets from lab, derivations, calculations (include at least one complete set of sample calculations), and any other related information which supports the executive summary. F. 1. 2. DESIGN-BUILD-TEST PROJECT: Design-build-test project teams will be organized to compete in the EPDACI Student Concrete Beam Competition. The competition objectives are to design, construct and test a concrete beam reinforced with steel bars to achieve optimal ultimate load; and to predict the ultimate load and the load that will result in a midspan deflection of 1/4 inch. Two cash prizes will be awarded by EPDACI – one prize for the student team that best achieves the optimal ultimate load and one prize for the student team that achieves the best predictions. Student teams will be required to develop and evaluate several alternative designs for achieving the competition objectives, and to justify the design alternative they choose to use in the competition. The development and evaluation of alternative solutions to the competition problem will be an important element in the project grade, and must be clearly explained in the project reports which are described in the next paragraph. Each group will submit the following for their design-build-test project: Project Proposal: The proposal must include a discussion of your team’s objectives for the project, a description and evaluation of the alternative designs your team considered, the design your team is proposing to build along with a justification for your choice, dimensioned AutoCAD drawings of your proposed beam geometry including location of reinforcement, your concrete mix design, and a bill of materials for the supplies you will need to construct your beam. If the project will 10 require the purchase of materials or supplies (other than plywood for formwork, steel rebar, Type I cement, sand, and generically available coarse aggregates and admixtures), your proposal should also include information on costs for the “extra” materials. Written Group Project Report: In general, the same requirements that apply to writing a full laboratory reports will apply to writing the final design-build-test project report. However, unlike the laboratory reports which are prepared by each student individually, the design-build-test project report is prepared as a single group report from the project team, organized in a similar manner to the individual lab reports. However, for this report, you will also need to include a separate section on “Design Alternatives” which comes after the Introduction and covers the development and evaluation of the alternative solutions you considered for achieving the project objectives, and explains the reasons for the design you chose to use. You will also need to include a “Theoretical Background” section, which should help to explain the prediction calculations you will make for ultimate load and deflections. Your “Theoretical Background” section will provide the background for and be closely related to the “Methods of Data Analyses” that you include in the “Methods and Procedure” section of your report. Your Conclusions section should include your evaluation of how your chosen design performed relative to your reasons for choosing it, “lessons learned,” and suggestions as to what you would do differently if you had the opportunity to redo the project. Oral Report: Each team will make a 20 to 30 minute oral presentation about their project. As your audience will be other student teams who also completed the project, your report should concentrate on the development and evaluation of the alternative solutions you considered for achieving the project objectives, your team’s specific project objectives, your final design and your reasons for choosing it, discussion of results including a comparison of your predictions with your experimental results, your evaluation of how your chosen design performed with lessons learned and suggestions for improvements. Preparation of the oral report should wait until the written report has been prepared. Practice speaking on your feet without reading what you wish to say. Note cards and notes within PowerPoint or another presentation program are certainly acceptable and are often a good idea, but the speech should not be read word for word from them. Graphical and technical aids should be prepared well in advance, making sure that they are readable and not too “wordy.” Be prepared to answer questions from the audience once everyone in your group has finished speaking. Gear your talk to the level of the audience--do not try to "snow" them, or be flip in explaining what you did. There is no room for technical dishonesty--if the project didn't work, concentrate on why rather than trying to "explain away" mistakes. 11 II. LABORATORY POLICIES Most laboratory regulations are in effect for one of two reasons: to protect the student or to protect the equipment. The following rules must be observed by all students utilizing the laboratory: 1. Any accident which results in damage to person or property (yours or Widener's), no matter how minor, must be reported to the instructor as soon as possible. First aid materials are available from the instructor and/or lab technicians. 2. Eye protection shall be worn at all times in the laboratory when experimental work is being performed. 3. Smoking, eating, and drinking are not permitted at any time in the laboratories. 4. Horseplay, which is dangerous in a laboratory environment, will not be tolerated and will result in dismissal and a failing grade. 5. Laboratory experiments are designed to be completed during scheduled laboratory periods. If for some reason a group does not complete a lab in class, it will be necessary to make up the lab outside of class time. Makeup time must be approved in advance by the lab instructor. Outside of class periods, students may not work alone in a laboratory but rather, for safety reasons, must work in a minimum group of two. When students have finished their work, they must secure the room (close windows, disconnect power, switch off lights, clean up work area, return equipment to storage, lock doors, etc.). 6. Equipment must be handled carefully, with due attention paid to possible hazards. Students should understand procedures before beginning work. Consult the equipment manual or the instructor if there is a question about proper operation. 7. The laboratories must be left in a clean and tidy state, with equipment put away and messes thoroughly cleaned up. Failure to do so will result in the lowering of your grade. 12 III. Technical Writing Assignment: Review of Journal Article A. Objectives: 1. To become familiar with accepted format and style of writing for engineering lab reports, project reports, and research articles. 2. To access current civil engineering research articles, and to review these articles in terms of technical writing standards. B. References: Example Lab Report for CE 306. (Davis, 2003). Lab Report Editing and Review Guide (Davis, 2003) C. Background: The most current information on engineering topics can be found in research journals that are often published by professional societies, such as The American Society of Civil Engineers (ASCE). These articles are reviewed and edited before they are accepted for publication to ensure that the article conforms to technical writing standards as well as technical content standards of the journal. D. Procedure: 1. Search the library’s on-line journals for a technical research article a. The article should include experimental work and preferably also analytical calculations b. The article must be approved by the instructor before you leave the lab. c. You will need to attach an electronic copy of the article to your submission – you can obtain an electronic copy of the article by downloading it to the desktop and then emailing it to yourself or putting it on a thumb drive. d. Options for articles are as follows, or you may choose your own: Shear Behavior of Corrugated Tie Connections in Anchored Brick Veneer–Wood Frame Wall Systems by: Nikola V. Zisi and Richard M. Bennett, JOURNAL OF MATERIALS IN CIVIL ENGINEERING © ASCE / FEBRUARY 2011 13 Fire Survivability of Externally Bonded FRP Strengthening Systems by: S. K. Foster and L. A. Bisby, JOURNAL OF COMPOSITES FOR CONSTRUCTION © ASCE / SEPTEMBER/OCTOBER 2008 Scour at Vertical Piles in Sand-Clay Mixtures under Waves, by: Subhasish Dey; Anders Helkjær; B. Mutlu Sumer; and Jørgen Fredsø, JOURNAL OF WATERWAY, PORT, COASTAL, AND OCEAN ENGINEERING © ASCE / NOVEMBER/DECEMBER 2011 Shrinkage and Fracture Properties of Semiflowable Self-Consolidating Concrete, by: Gilson Lomboy; Kejin Wang, M.ASCE; and Chengsheng Ouyang, JOURNAL OF MATERIALS IN CIVIL ENGINEERING © ASCE / NOVEMBER 2011 Results from 18 Years of In Situ Performance Testing of Landfill Cover Systems in Germany, by: Stefan Melchior; Volker Sokollek; Klaus Berger; Beate Vielhaber; and Bernd Steinert, JOURNAL OF ENVIRONMENTAL ENGINEERING © ASCE / AUGUST 2010 2. To use the library: a. Go to Widener.edu b. Click on Library in quick links c. Go to Wolfgram Library d. Go to Find Articles e. Scroll through all Journals held until you find ASCE Publications f. Select an ASCE Publication g. Either scroll through recent journals by table of contents or search the entire ASCE journal for a subject of your interest. 3. Review the article with respect to the following assignment. Provide short answers to the questions and highlight and identify (by topic #) the sections of the article that refer to each topic. a. Technical Writing Assignment: Review a Technical Journal Article b. Select a technical article in an ASCE journal (Materials or Structures) that involves experimental measurements taken by the authors. Review the article with respect to the following questions. THIS ASSIGNMENT IS NOT DONE IN LAB REPORT FORMAT. 14 1. Provide a bibliographic listing (citation) of the article. Sample citations for different types of documents are provided in Chapter 11: Ethics and Documentation in Engineering Writing section of your textbook. 2. Outline the main headings and sub-headings 3. Figures and tables: Answer the following questions: a. Are all tables and figures identified by number with a brief descriptive title? If not, which tables and figures do not contain this information b. Are the table number and title located above or below the table? c. Are the figure number and title located above or below the figure? d. Are all tables and figures discussed in the article and appear on the same page or the following page after they are first discussed? Which tables and figures, if any, do not meet these criteria? e. Is there consistent use of abbreviations for units? 4. Equations: a. Are equations numbered and discussed in the text? If not, state the page number in the article where equations are not numbered or discussed. b. Are the variables (the symbols used in the equations) defined directly after the equation? If not, where are the symbols defined? For the following parts, print out a copy of the journal article and highlight the text in the article that corresponds to the question and write the type of content beside the highlighted text (i.e. background, objective, scope of work, conclusion, etc…). 5. a. b. c. d. e. Abstract Identify a background statement (if there is one) Identify the statement of objective(s) Identify the statement(s) of scope of work. Identify the significant results or findings. Do the results address the objectives? (Yes / No) Circle One 6. a. b. c. d. Introduction: Identify a background statement (if there is one). Identify the statement of objectives. Identify the statement(s) of scope. Identify background information or a literature review. 15 7. Methods and Procedures: a. Circle five (5) verbs that represent past tense. b. Circle five sentences that represent passive voice. c. Circle any instances where personal pronouns are used. If none are used, write “no personal pronouns” next to the heading. d. Identify pictures or drawings used to illustrate equipment or test procedures. If none are used, write “no drawings or illustrations” next to the heading. e. Identify any analytical procedures. If none are used, write “no analytical procedures” next to the heading. 8. Results and Discussion: a. Are all figures and tables discussed in the text before they are shown? If not, which table or figure is not discussed in the text before it is shown. b. Identify a table where raw or summarized data is shown. c. Identify text that is used to discuss the data in the table. d. Identify a graph where relationships between variables are shown. e. Identify text that is used to discuss the figure. 9. Summary and Conclusion: a. Identify a statement of objective (if present). b. Identify a summary of significant results (if present). c. Identify the concluding statements (not a summary of results, but what is concluded from the results). 16 IV. Lab #1 Concrete Mix Design and Compression Tests A. Objectives: 1. To familiarize the student with the general characteristics of concrete and concrete materials and with laboratory methods of manufacture and test of concrete specimens 2. To determine the effect of varying design mixes and materials (water, cement, sand, and coarse aggregate) on the consistency of the fresh concrete and on the strength of the hardened material. B. References: ASTM C143-12 Standard Test Method for Slump of Hydraulic-Cement Concrete ASTM C39-05 Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens ACI Committee 211 Standard Practice for Selecting Proportions for Normal, Heavyweight, and Mass Concrete, ACI 211.1-91, American Concrete Institute, 2002 ACI Committee 214 Evaluation of Strength Test Results of Concrete, ACI 214R-02, American Concrete Institute, 2002 C. Background: Portland cement concrete is a widely used building material for many reasons: it can be readily formed into many shapes; it is both durable and corrosion resistant; it provides fire protection and water tightness; and has a relatively high compressive strength. Although concrete exhibits low tensile strength, this disadvantage can be overcome by reinforcing it, normally with steel. The properties of concrete, in both the freshly mixed and the hardened state, are closely associated with the characteristics and relative proportions of its components. The solid portion of the hardened concrete is composed of the aggregate and a new product which is the result of a chemical combination of cement with water. The remaining portion of the space occupied by a given volume of concrete is composed of free water and air voids, with the air voids usually not occupying more than 1 or 2% of the volume, unless special chemicals (air entraining admixtures) are used to trap more air voids in the concrete. After a period of time, the amount of free water depends on the extent of chemical combination of water and cement, called hydration, and loss from evaporation. 17 The cement-water paste is the active component in the concrete and the properties of the water-cement paste depend upon the characteristics of the cement, the relative proportions of cement and water, and the completeness of the chemical combination or hydration. The completeness of the hydration requires time, favorable temperatures, and the continued presence of moisture. The period during which the concrete is definitely subjected to these conditions is called curing. On construction work, curing may vary from 3 to 10 days; in the laboratory the common curing period is 28 days. Good curing is essential for the production of quality concrete. There are five types of Portland cement, as indicated below: Type I. Type II Type III Type IV Type V For use in general concrete construction when the special properties specified for the other four types are not needed For use in general concrete construction exposed to moderate sulfate action, or where moderate heat of hydration is required For use when high early strength is required For use when a low heat of hydration is required For use when high sulfate resistance is required All types are made of approximately 60% lime-bearing material and 40% of a clayey material, which are ground, mixed together, and then heated to fusion. The product is then ground fine and mixed with about 3% gypsum. A sack of cement contains 1 cubic foot of material and weighs 94 pounds. The sand and gravel (fine and coarse aggregate) used in a concrete mixture should be well proportioned or graded from fine to large particles. Sands generally vary in particle size from 1/4" down to those that pass a 100 mesh sieve (10,000 openings per square inch). Gravels vary upward from 1/4" to 1.5" and often to 2.5". If the sand and gravel are well graded, the void space will be minimized and less cement paste will be needed to produce concrete. Concrete mix proportions may be based on volume or weight of materials and are stated, for example, as 1-2.5-3.5 mix by volume, meaning that 1 part of cement, 2.5 parts of sand, and 3.5 parts of gravel, all by volume, should constitute the mix. The water-cement ratio (quantity of water divided by quantity of cement used) is the single most important factor influencing the strength of the final product. The only property of concrete which improves with a higher water-cement ratio is the workability, or the ease with which the concrete can be placed. Consistency relates to the state of fluidity of the mix and ranges from the driest to the wettest mixtures. The most common test to determine consistency is the slump test (ASTM C143), which is performed by measuring the subsidence, or slump (in inches), of a pile of concrete 12" high, formed in a mold that has the shape of a cone. 18 The tendency for water to rise to the surface of freshly placed concrete is known as bleeding, and results from the inability of the material to hold all the mixing water. Concrete subject to bleeding is not as strong or durable as concrete that does not bleed. The strength of concrete is taken as an important index of its quality. Strength tests are commonly made in compression and flexure and occasionally in tension. The compression test of a 6 by 12-inch (or 4 by 8 inch) cylinder at age 28 days, after moist storage at a temperature of 70oF, is a standard ASTM test (ASTM C39). The compressive strength of concrete, made and tested under standard conditions, ordinarily varies from 2500 to 6000 psi, although much higher strengths can be obtained by using special additives. The tensile strength of concrete is roughly 10% of the compressive strength; and the flexural strength (strength in bending) of plain concrete, as measured by the modulus of rupture, is about 15 to 20% of the compressive strength. The principal factors affecting strength are: 1. Water-cement ratio--the higher the water content, the lower the strength. 2. Age--the strength of concrete generally increases with age, although practically all the strength has been achieved after 28 days. 3. Character of the cement--the finer the cement, the higher the strength. 4. Curing condition--the greater the period of moist storage, the higher the strength. Evaluation of strength data is required in many situations, such as: • Evaluation of mixture submittal; • Evaluation of level of control (typically called quality control); and • Evaluation to determine compliance with specifications (job-site acceptance testing) A strength test result is defined as the average strength of all specimens of the same age, fabricated from a sample taken from a single batch of concrete. A strength test cannot be based on only one cylinder; a minimum of two cylinders is required for each test. Concrete tests for strength are typically treated as if they fall into a distribution pattern similar to the normal frequency distribution curve. A sufficient number of tests are needed to indicate accurately the variation in the concrete produced and to permit appropriate statistical procedures for interpreting test results. To satisfy statistically based strength-performance requirements, the average strength of the concrete fcr′ should be in excess of the specified design compressive strength fc′. The required average strength fcr′ used in mixture proportioning depends on the expected variability of test results as measured by the coefficient of variation or standard deviation. The strength test record used to estimate the standard deviation or coefficient of variation should represent a group of at least 30 consecutive tests. If the number of test results available is less than 30, a more conservative approach is needed; and when the number of strength test results is less than 15, the calculated standard deviation is not sufficiently reliable to be of use. In those cases, the concrete is proportioned to produce much higher average strengths fcr′ than the specified design strength fc′. 19 The strength of concrete in a structure and the strength of test cylinders cast from a sample of that concrete are not necessarily the same. The strength of the cylinders obtained from that sample of concrete and used for contractual (job-site) acceptance are to be cured and tested under tightly controlled conditions. The strengths of these cylinders are generally the primary evidence of the quality of concrete used in the structure. The engineer specifies the desired strength, the testing frequency, and the permitted tolerance in compressive strength. It is impractical to specify an absolute minimum strength, because there is always the possibility of even lower strength test results simply due to random variation, even when control is good. D. Materials: Type I Portland cement, sand, gravel, and lubricant for molds E. Equipment: For mixing: scale for weighing, concrete mixer or mixing pan, shovels, trowel, slump cone, 12" scale, tamping rod, measuring beakers, mallet, wet towels, plastic, 3” by 6" or 4” by 8” cylinder molds (Note: 3 by 6” cylinders are not permissible when testing concrete strength by ASTM C39) . For testing: rigid end caps, and concrete testing machine. F. Procedure: This experiment requires several laboratory periods. During the first period, concrete mixes will be designed and cylinders prepared for testing. Cylinders will be tested at four weeks (28 days) and either one week (7 days) or two weeks (14 days) after the first period. Specific instructions regarding the mix design will be given at the time of the experiment, using ACI 211.1-91 Standard Practice for Selecting Proportions for Normal, Heavyweight, and Mass Concrete. Results will be compiled from all groups, with each group using a different water-cement ratio for comparison and analysis. a. 1. Concrete Mix Preparation Design one batch of non-air-entrained concrete, following the guidelines of the American Concrete Institute. Mix enough concrete to mold four test cylinders and to fill a slump cone. Mix the materials by first combining the sand and cement, then adding the gravel, and finally the water. Keep accurate records on the amount (by weight) of each of the materials used. 2. Once a mix has been prepared, its consistency should be measured with the slump cone apparatus, which is a truncated cone conforming to ASTM specifications. To make the slump test (ASTM C143), dampen the slump cone, scoop, tamping rod, and metal working surface. Holding the cone in position by standing on the foot pieces, fill the slump cone in three equal layers, rodding each layer 25 times with the tamping rod, making sure to cover the full area of the concrete with the tamping motion and that the 20 3. 4. 5. 6. strokes barely penetrate into the previous layer. For the final layer, pile the concrete above the top of the cone to account for settlement. If the level settles below the top of the cone, add additional concrete. Carefully strike off the surface using the tamping rod. Raise the slump cone by means of the handles, without any twisting or side motion. Place the cone next to the concrete, with the tamping rod over the cone. If one side of the concrete falls away or shears off, repeat the test. Measure the slump to the nearest 1/4" and classify the mix as wet (over 6"), normal (1-6"), or stiff (under 1"). The slump test is a good field test for consistency and may actually be used to determine the amount of mixing water. If the mix is outside the "normal slump" range, mix the concrete again and make adjustments to bring it into the normal range. If the slump is greater than that required, add more fine and/or coarse aggregates. If the slump is less than required, water and cement in the appropriate ratio should be added. Make sure that accurate records are kept of whatever materials are added so that the actual ratio of materials can be reported. Observe the general characteristics of each mix, making note of its troweling workability. To determine troweling workability, work the concrete with a trowel. If it works smoothly and with little effort, the troweling workability may be called good. Rate as good, fair, or poor. Fill the molds completely in three equal layers, tamping each layer 12 times, and each time tapping the sides of the mold 5 to 10 times with a mallet to remove air voids. Overfill the third layer to account for consolidation. Finish the top by striking off with the tamping rod and troweling it smooth. Cover the top immediately to prevent evaporation. Properly identify samples and clean up work area, equipment and tools. Arrange for proper curing of your specimens (moisture and temperature). Strip the molds from the specimens after about a 24-hour curing time. The samples then should be submerged in water or stored under wet burlap covered with plastic for 7 days. b. Compression Testing of Concrete Cylinders 1. Prior to compression testing, measure the diameter of the concrete cylinder using calipers. Measure the cylinder at mid-height at four different locations around the circumference of the cylinder. 2. Before testing the compression cylinders they must be capped on the ends to permit uniform bearing when the load is applied. A cap is a small plane surface of suitable material, such as gypsum plaster or hardened steel. Wipe clean the bearing faces of the hardened steel bearing caps and of the test specimen. Insert the test specimen into the bearing caps. 3. Place the test specimen with bearing caps in place on the table (platen) of the testing machine directly under the spherically seated (upper) bearing block. Wipe clean the bearing faces of the upper and lower bearing blocks. Seat the specimen in the testing machine and close the protective doors. 4. Apply the load continuously and without shock, at a constant rate within the range of 20 to 50 psi per second. During the application of the first half of the estimated maximum load, a higher rate of loading may be 21 permitted. Do not make any adjustments in the controls of the testing machine while the specimen is yielding rapidly (immediately before failure). Increase the load until the specimen fails, and record the maximum load carried by the specimen during the test. Note the type of failure and the appearance of the concrete if the break appears to be abnormal. Standard failure modes are shown in Figure 1. MAKE SURE THE PLATEN DOES NOT RISE ABOVE THE MAXIMUM HEIGHT MARKED ON THE TESTING MACHINE. Fig. 1 Concrete Cylinder Compression Failure Modes G. Calculations: 1. Record data from all lab groups in your lab section. Develop a data table to record the details and test results of each cylinder, including: Group # Specimen # Mix date Test date Mix design proportions by weight Targeted compressive strength Cylinder size Slump Workability Ultimate load Ultimate compressive strength, and Type of fracture. Data tables will be shared among all groups by posting to shared files on the Campus Cruiser course web page. 2. The actual compressive strength is calculated as the failure load divided by the cross-sectional area of the specimen. Report the strength to the nearest 10 psi. 3. Calculate the average compressive strength and range (difference between maximum and minimum strengths) for cylinders from the same mix (i.e. by lab 22 groups in your section) and test date (i.e. same age at testing). Discuss the effect that age at testing has on compressive strength. 4. Using the average 28 day strengths for the different mix designs, plot a curve showing the compressive strength as a function of water/cement ratio, and discuss if your curve follows the expected trend. 5. Did your mix designs produce the strengths you were expecting at 28 days? What are some reasons why the actual average compressive strengths might not agree with the targeted compressive strengths from the mix designs? 6. The targeted compressive strength is the strength that is expected to be produced on average from a mix design. It is also known as the required average strength, fcr′, but is NOT the same as the specified strength, fc′, engineers use in structural design calculations. The targeted strength must be larger than the specified structural design strength, fc′; how much larger depends on the quantity of test results available. The fewer the tests, the larger the amount by which fcr′ must be greater than fc′. For cases where there are not enough strength tests to establish a standard deviation (i.e. when there are less than 15 strength tests), the average compressive strength fcr′ must exceed the design strength fc′ by fcr′ ≥ fc′ + 1000 when fc′ < 3000 psi fcr′ ≥ fc′ + 1200 when fc′ is between 3000 and 5000 psi fcr′ ≥ 1.10 fc′ + 700 when fc′ > 5000 psi Based on the above, make recommendations for reasonable values for design strength fc′ for which your concrete mix designs could be used. 23 V. Lab # 2: Measuring Tensile Properties of Metal Specimens A. Objectives: 1. To measure and compare the strength and several elastic and nonelastic properties of metal specimens To compare the measured values of each property to reference values reported in the literature To observe and compare the differences in the behavior of materials under load, To study the types of fractures. 2. 3. 4. The specific properties to be determined are: 1. Elastic strength in tension: a. Modulus of Elasticity b. Yield point (upper and lower if possible) c. 0.2% Yield Strength d. Proportional Limit 2. Ultimate tensile strength 3. Rupture Strength (True and Engineering) 4. Ductility: a. Percent elongation in 2" b. Percent reduction in area B. References: Davis, Troxell, and Hauck, The Testing of Engineering Materials, 4th Edition, McGrawHill, 1982, Chapters 2, 8, and 13. ASTM E8-04 Standard Test Method for Tension Testing of Metallic Materials C. Background: The static tension test is probably the most common and simplest of all the mechanical tests. When properly conducted on suitable test specimens, the tension test comes closest to evaluating fundamental mechanical properties for use in design, although the material properties found by tension testing are not necessarily sufficient to enable the prediction of performance of materials under all loading conditions. In the tension test, a prepared specimen is subjected to gradually increasing (i.e., static) uniaxial load until failure occurs. This operation is accomplished by gripping opposite ends of the piece of material and pulling it apart. The test specimen elongates in a direction parallel to the applied load. 24 The test specimens are usually either cylindrical or rectangular in shape and of approximately constant cross section over the length within which measurements are made. A uniform distribution of stress should develop over the critical cross section perpendicular to the direction of the load In tension test of metals, the properties usually determined are yield strength, tensile strength, ductility (percent elongation), and type of fracture. In more complete tests, determinations of stress-strain diagrams (Fig. 1), modulus of elasticity, and other mechanical properties are included. It is customary to compute stress on the basis of the cross-sectional dimensions before loading and to compute strains on the basis of the original length between gage marks. Stresses and strains based on the original dimensions are sometimes called nominal, conventional, or engineering stresses and strains as opposed to the true stresses and strains which are computed on the basis of the instantaneous (and changing) dimensions. Other terms of importance in this experiment are summarized below. Elasticity is the property of a material by which deformations disappear upon removal of the stress. In tests of material under uniaxial loading, three criteria of elastic strength or elastic failure have been used: the elastic limit, the proportional limit, and the yield strength. The elastic limit is defined as the greatest stress a material is capable of developing without a permanent deformation (set) remaining when the stress is removed. To determine the elastic limit would require successive applications and release of greater and greater loads until a load is found at which permanent deformation is produced. The determination of the elastic limit is too involved to be practical and thus is rarely made. The proportional limit σP is defined as the greatest stress that a material is capable of developing without deviating from straight line proportionality between stress and strain. Most materials exhibit this linear relation between stress and strain within the elastic range, and the values of the elastic limit for metals do not differ greatly from the values of the proportional limit, which is determined by use of a stress-strain diagram. The modulus of elasticity (E) of a material is the ratio of stress to corresponding strain within the proportional limit. In terms of the stress-strain diagram, the modulus of elasticity is the slope in the initial straight line portion of the curve. The determination of the proportional limit can be imprecise because of difficulty in detecting when the stress-strain curve ceases to be a straight line. Thus, the yield strength σY can be used as a measure of elastic strength. The yield strength is most often determined by the offset method. A given value of strain (0.002 in/in or 0.2% is most commonly used for ductile metals) is laid off along the horizontal axis of the stress-strain diagram. A line parallel to the initial straight line portion of the stress-strain diagram is drawn from the offset point. The value of stress where this line intersects the stress-strain diagram is the yield strength for the specified offset. 25 Figure 1 – Example of a Stress-Strain Diagram If the test is conducted at an appropriate speed with a ductile material, it is possible to distinguish between two critical points in the yield range, the upper yield point and the lower yield point. Although the upper yield point is the one usually reported, it is very sensitive to the rate of loading, and it appears that the lower yield point is of more significance, as far as the fundamental properties of the material are concerned. Stiffness has to do with the relative deformability of a material under load. It is measured by the rate of stress with respect to strain. The greater the stress required to produce a given strain, the stiffer the material is said to be. As the sample is loaded in tension, it elongates in the axial direction, while the lateral dimensions get shorter (contracts). The ratio of the absolute value of the lateral strain to the axial strain is called Poisson's Ratio. For steel, Poisson's Ratio may range from 0.250.35, so the lateral strains are only 1/4 to 1/3 that of the axial strain. Ductility is the property of a material that enables it to undergo considerable deformations before rupture and at the same time to sustain a considerable load. Mild steel is a ductile material. A nonductile material is said to be brittle; that is, it fractures with relatively little or no elongation. Cast iron and concrete are brittle materials. Usually the tensile strength of brittle materials is only a fraction of their compressive strength. The usual measures of ductility are percent elongation and percent reduction of area in the tension test. Ductile materials will "neck down" prior to fracture; that is, the reduction in the cross-sectional area can actually be observed during the test. The term ultimate strength has to do with the maximum stress a material can develop. Ultimate strengths are computed on the basis of the maximum load carried by a test piece and its original cross-sectional dimensions. The tensile strength is the ultimate strength in uniaxial tension. The stress at failure is sometimes called the breaking stress or rupture stress; engineering rupture stress is calculated using the original cross-sectional area, while true rupture stress is calculated using the cross-sectional area after failure. 26 When conducting tests to failure of materials and of structural parts or members, it is important to observe and to record the type of failure and the characteristics of the fracture. This observation should include the phenomena associated with final rupture and evidence of change of condition such as yield, slip, scaling, necking down, local crack development, etc. Although observations of failure are qualitative, much can be learned from a study of failures, and with experience it is possible to recognize from a break the kind of stress that caused failure and the type of material. In this connection it is important to be alert in order to discover the presence of flaws and defects, for premature failure is often caused by defects. D. Specimens: Each group will be given standard threaded specimens of different materials for testing to failure. E. Equipment: Tinius-Olsen machine, extensometer, data acquisition software, dial calipers, 2" gage punch, reduction of area gage. F. Testing Procedure: Each group will be given specimens of different materials to test. Groups will take turns in testing the specimens. The data collected by each group will be shared with the entire class. Repeated tests for a given specimen type will allow calculation of a mean, variance, and standard deviation. 1. Measure and record the diameter of each specimen using the standard micrometer. 2. Make 2-inch gage marks on each specimen using the 2" gage punch. Note: Do not hit. Push down with the hand or lightly tap. 3. Start the testing machine in accordance with the appropriate instructions. 4. Install the specimen. 4. Install the extensometer. 5. Select the appropriate testing program to plot the stress versus strain curve, and load the data acquisition program to download the test data (load, strain, and elongation). 7. Load the specimen, removing the extensometer from the specimen after the material starts to yield but before necking begins. 27 8. Continue the test until the specimen ruptures (breaks). Record ultimate (maximum) load and load at rupture. (See #1 under Measurements & Calculations.) 9. Remove the broken specimen and shut off the machine (if finished testing) following the operating instructions. DO NOT SHUT OFF THE MACHINE UNDER LOAD!!!!! 10. Note the geometry and appearance of the fracture. Measure and record the final diameter of the necked section using the reduction of area gage or calipers. Measure and record the final gage length between the set of 2" gage marks most closely centered on the break. G. Measurements and Calculations: a. Prepare a data table to record the following information for all specimens tested; data tables will be shared among all groups by posting to shared files on the Campus Cruiser course web page. Group ID: Specimen ID: Material: Diameter (in) Cross-sectional area (in2) Gage Length (in) Yield Load (lb) Ultimate Load (lb) Rupture Load (lb) Final Diameter (in) Final Cross-sectional area (in2) Final Gage Length (in) 2. Use the load and strain data from the data acquisition software to develop a stress vs strain plot to illustrate material properties for the specimens your group tested. The stress-strain diagrams (for your group’s specimens) should be included in the Results and Discussion section, and the graphs should be labeled to illustrate the material properties determined from the tensile test (for example, the value for E should be shown as the slope of the linear portion of the stress-strain graph, the proportional limit, yield stress, etc should be labeled). 3. Compute the following parameters for the specimens your group tested. At least one complete set of sample calculations should be provided in the Appendix of the report. Prepare a table to present the results for your specimens. 28 a. b. c. Modulus of Elasticity (psi) Proportional limit (psi) Yield Point (psi) - not all specimens have a definite yield point, while others will have both upper and lower yield points. d. Yield Strength at 0.2% Offset (psi) e. Ultimate Strength (psi) f. Rupture Strength (psi) - use original area g. True Rupture Strength (psi) - use final area h. Percent Reduction in Area i. Percent Elongation Note: Modulus of Elasticity, yield point and yield strength at 0.2% offset can be computed using each specimen’s load-strain-elongation data. All other properties can be determined using information recorded in the data tables. 4. For each type of material tested (i.e. for steel samples and for aluminum samples), prepare a table (see format below) to summarize results from all groups for yield strength, ultimate strength, rupture strength, % elongation, and % reduction of area. Calculate the means and standard deviations. Which property tends to be the most uniform or consistent among different specimens of the same material? Which properties show a large amount of variation? Specimen Type________________________ Property Group #1 Group #2 Group #3 Avg. Standard Deviation Yield Strength, ksi Ultimate Strength, ksi Rupture Strength, ksi % Elongation % Reduction of Area 5. Reference values (modulus of elasticity, yield strength, ultimate strength, percent elongation) for each specimen should be obtained (Matweb.com is a good data source) and compared to your results. In your discussion of results, compare the material properties you determined to published values for similar materials. What sources of error or variability were significant for your results? Which material was strongest? Which material was most ductile? How did the change in cross-sectional area affect the value of the rupture strength? 29 VI. Lab #3 Measuring Forces in Truss Members Using Strain Gages A. Objectives: 1. To become familiar with the operation and application of electrical resistance wire strain gages to measure stresses in simple structures. 2. To experimentally determine the internal forces in simple structures, and to compare those results with values obtained analytically. B. References: The chapter on truss analysis in any Structural Analysis (or Statics) textbook C. Background: The elastic stretching or straining of steel is of the order of one to four thousandths of an inch for each inch of length. The accurate measurement of such strains can be made by mechanical, optical, or electrical gages. The first strain gages were mechanical, but today strains are usually measured with electrical strain gages. An electrical resistance wire device, known as the SR-4 strain gage, consists of loops of very fine wire cemented to a thin paper strip. The gage is cemented to the specimen with a firm, tough cement that allows the gage to stretch with the specimen to which it is attached. The changes in length of the wires alter their electrical resistance, which is measured and calibrated to indicate the actual strain. Proper bonding of the gages to the member is essential for obtaining reliable results. Care must also be taken that the gage does not absorb moisture, since this will cause resistance changes which affect gage stability. Strains are determined by placing a wire gage in a four-arm Wheatstone bridge d-c circuit. When the gage resistance is changed by deformation of the gage, the bridge circuit is unbalanced. To compensate for strains caused by temperature and humidity variations, a so-called dummy gage (a duplicate of the active gage) is connected into the Wheatstone bridge circuit. The active gage measures strain due to stress, plus deformations due to temperature and humidity effects, while the dummy gage measures deformation due to temperature and humidity effects only. Although this setup can be used satisfactorily, it is more convenient to contain the Wheatstone bridge setup within a specially designed strain indicator. The strain indicator is calibrated to read strains (rather than resistances), and includes electronic amplification to get a stronger signal. 30 To obtain direct or axial strain averaged from two sides of a tension or compression member and at the same time to cancel out unwanted bending strains, two active gages can be mounted back-to-back on opposite sides of the specimen. In this experiment, strain gages will be used to determine the forces in the members of a truss. A truss is defined as a structure consisting entirely of straight two-force members that are pin-connected together at their ends. These connection points are called joints, and it is further specified that all loads are applied to the truss at the joints, rather than along the members. When a truss is subjected to an external load, the members develop internal axial forces which are related to the applied external load by the geometry of the truss and the magnitude, location, and direction of the applied load. Figure 1 – Example of a Truss Trusses may be analyzed by the method of joints, which consists of taking free body diagrams of joints in the truss and solving the force equilibrium equations for the member forces. In addition, if the strain in a member is measured, the stress in that member can be found from Hooke's Law (stress = Modulus of Elasticity times strain). Once the stress is determined, the axial force in a member can be found (stress = P/A so P = stress times area). D. Specimens: Several pin-connected triangular trusses, each instrumented with strain gages, and constructed from 1018 steel (yield stress = 36,000 psi, E = 30,000,000 psi). Tests will be conducted on the following truss configurations: 45-45-90 truss; 60-60-60 truss; and 3060-90 truss. E. Equipment: Tinius-Olsen Testing Machine, digital strain equipment, dial calipers F. Procedure: 1. Measure and record the cross-sectional dimensions and length of each member and pin. Check the strain gages for broken leads, making any necessary repairs. 2. Theoretically calculate the load to cause yielding of the most severely stressed member of each truss. Also calculate the force to cause failure in the pin connections. Through statics, these can be related to the external force being 31 applied to the truss by the Tinius Olsen machine. These calculations will be done in the lecture prior to the Truss Lab. 3. Theoretically calculate the critical buckling load for the truss. For a member to buckle, it must be in compression. From the Euler buckling equation, the force to elastically buckle a member equals 2 EImin/L2. Through statics, this member force can be related to the external force on the truss. These calculations will be done in the lecture prior to the Truss Lab. 4. Set up a truss in the Tinius-Olsen Testing Machine, making sure that loads and reactions are applied at truss joints and that they do not interfere with the members. 5. Connect the strain gages to the strain indicator and balance and calibrate all gages per instruction manual. 6. Apply five loads to the truss starting with the smallest load which gives a reasonable strain reading. The maximum load applied to the truss should be based on your calculations of the failure load divided by an appropriate factor of safety. The load increments should be approximately equally spaced between the first and fifth readings. Record the applied load and corresponding strain readings for all members. NOTE: Each truss member has two strain gages mounted on opposite sides of the member. Record readings from both gages, then average these readings to determine the strain for that member. Using the average of two strain gages for a single member eliminates unintentional bending effects. G. Calculations: 1. Find the forces in all truss members corresponding to each experimentally applied load, by appropriately relating average strain to stress (Hooke's Law) and stress to force (force = stress x area). b. Calculate all truss member forces analytically using the method of joints. 3 Compare the experimental results with the analytical values by calculating the absolute errors and the relative errors (%) with respect to the analytical value. 4. Discuss the results and sources of error and variability. 32 VII. Lab #4 Wooden Beam Tests A. Objectives: 1. To study the strength and rigidity of different types of wood. 2. To determine material properties and typical factors of safety for wooden beams. B. References: Western Wood Products Association Websites: www.wwpa.org www.lumberbasics.org www.wwpa.org/techguide C. Background: Structural lumber is graded for its strength and physical working properties; aesthetics are secondary. The basic framing classifications are organized by size classifications and performance capabilities. Dimension Lumber - 2" to 4" thick and 2" (nominal) and wider. Western Dimension Lumber design values, beginning in the Design Values section, are expressed as Base Values. These values must be adjusted for size and repetitive member use, prior to adjusting for other conditions of use. Dimension Lumber grades are divided into the following 3 classifications: structural light framing, light framing, and stud 1. Structural Light Framing (2x2 through 4x4, used where high-strength design values are required in light framing sizes, such as in engineered wood trusses.) Grades are: SELECT STRUCTURAL, No. 1 & BTR (DF-L, DF & Hem-Fir species only), No. 1,No. 2, No. 3 2. Light Framing (2x2 through 4x4, basic framing lumber, as used in most light-frame construction, e.g. wall framing, sills, plates, cripples, blocking, etc.) Grades are: CONSTRUCTION, STANDARD, UTILITY c. Stud (2x2 through 4x18, an optional grade intended for vertical use, as in load bearing walls.) The grade is: STUD Structural Joists & Planks (2x5 through 4x18, intended for engineering applications for lumber 5" and wider, such 33 as floor and ceiling joists, rafters, headers, small beams, trusses and general framing applications. Grades are: SELECT STRUCTURAL, No.1 & BTR (in Douglas Fir, Douglas Fir-Larch, or Hem-Fir species only.), No. 1, No. 2, No. 3 D. Materials: Wood beam specimens of different types and cross sections Adjustable beam supports, bearing plates, steel scale E. Equipment: Tinius-Olsen testing machine configured for compression testing F. Procedure: For each beam to be tested 1. Measure cross sectional dimensions and compare to nominal dimensions. 2. Position the beam in the Tinius-Olsen machine, to apply a concentrated load “P” at midspan. Use bearing plates between the supports and the wood and between the loading block and the wood. Record the beam span, and distance from supports to the load point. 3. Select the testing software to plot applied load “P” versus deflection at midspan. Apply load slowly until a significant failure occurs. Record ultimate load and sketch and identify the type of failure. G. Calculations: 1. Draw shear and bending moment diagrams as a function of applied load “P.” Where do the peak values for shear and moment occur? 2. Calculate the modulus of rupture for the wood fr = Mc/I at the ultimate load. 3. Using design values for wood in the National Design Specification (NDS) for Wood Construction published by the American Forest and Paper Association and the American Wood Council to calculate the factors of safety (modulus of rupture divided by allowable stress) for the bending stresses. Plot the factors of safety as a function of L/h (beam span divided by depth). Discuss any trends you see. 4. Using the formula Δ = PL3/48EI for the maximum deflection at midspan of a simply supported beam with a concentrated load at the midpoint, calculate the theoretical deflection at 25%, 50%, and 100% of ultimate load. Use values for modulus of elasticity E (not Emin which is used for beam stability) and moment of inertia I as given in the design aids from the Western Woods Producers (see attached tables). Plot the theoretical deflections from your calculations on the same graph as your experimental load versus deflection plot. Discuss why theoretical deflections should diverge from the experimental deflections as the load increases. 34 35 36 37 38 39 40 IX. Lab # 5 Beam Stresses and Deflections A. Objectives: 1. To use strain measurements to obtain values of the normal stress in a beam, and to compare the measured stress values with values computed from the bending stress equation. 1. To compare measured and theoretical values of beam deflections. 2. To compare how different support loading conditions affect beam stresses and deflections. B. References: Beer & Johnston, Mechanics of Materials, Chapter 4 and Sections 7.1-7.4. Chapters on beam deflections in any Structural Analysis text. C. Background: In this lab, a beam overhanging both ends will be tested, which is different from a simply supported beam, as seen in Figure 1. Although both beams have a pin (horizontal and vertical reaction forces) and roller (vertical reaction force) support, the bending moment and therefore the bending stresses will be 0 at the supports for the simply supported beam in Fig. 1b with the beam reactions at the ends of the beam. However, bending moment and stresses do not have to be 0 at a hinge or roller support when the beam overhangs the support, as seen in Fig. 1a. In this case, depending on loading arrangement, internal bending moment can be present at the supports. When typical gravity (downward) load acts on the beam overhangs, the bending moment at the supports will be negative, and thus the bending stresses at the supports will be tension on the top and compression on the bottom of the beam. Two different load arrangements will be tested in this lab, as shown in Fig. 2. For each load arrangement, mid-span deflection will be measured directly by using a deflectometer, while bending stresses at mid-span and at one of the supports will be determined indirectly from strain gages. Fig. 1a: Beam overhanging both ends Fig. 1b: Simply supported beam 41 a b P/2 a P/2 Fig. 2a: Loading Condition 1 a b a P/2 P/2 Fig. 2b: Loading Condition 2 Although it may not be obvious, drawing shear and bending moment diagrams will show that the loading condition in Fig. 2a is identical to that in a simply supported beam with a length L = 2a+b; the moment (and bending stress and strain) at the hinge and roller supports are equal to 0 and the maximum moment is positive and constant between the two loads. However, the bending moment diagram for the beam in Fig. 2b looks entirely different, with negative moment occurring at the supports. Likewise, the deflections at mid-span are very different for the two loading conditions. The loads in Fig. 2a cause the beam to deflect downward with maximum deflection at mid-span, while the loads in Fig. 2b cause the beam to deflect upward at mid-span. The theoretical deflections for either loading case can be calculated by several different methods, including the moment-area method, conjugate beam, or by integrating the differential equation of the elastic curve. D. Specimens: 1018 steel tubing 2 x 1.5 x 1/8” wall thickness. For the steel, E = 29 x 106 psi and σy = 50 ksi. E. Equipment: Tinius Olsen machine, deflectometer, digital strain indicator F. Procedure: 1. Draw shear and bending moment diagrams for both loading arrangements and calculate safe design loads, based on an allowable bending stress = 0.6σy. 42 2. Measure the dimensions of the beam, and mount it on the supports in the testing machine. Carefully connect the strain gages to the digital strain indicator and balance and calibrate all gages. Position the deflectometer under the midspan of the beam, being careful to not disturb the strain gages. Position the load apparatus to apply two concentrated loads in the middle of the beam span. 3. Apply five loads to the beam. The maximum load applied should be based on your calculations for the safe design load. The load increments should be approximately equally spaced. Record the applied load and corresponding strain readings for all members, as well as the deflectometer reading for the mid-span deflection. 4. Set up the beam as in step 2, but this time position the load apparatus to apply two concentrated loads symmetrically on the overhangs. Repeat step 3 for the case with loads applied to the overhangs. G. Calculations: 1. Experimental Stresses: Find the stress from each strain gage corresponding to each experimentally applied load, by appropriately relating strain to stress using Hooke's Law. 2. Theoretical Stresses a. Draw shear and bending moment diagrams for your beam for the two loading conditions. On the moment diagram, locate the points where strain gages are located. These are the points at which theoretical stresses will be computed. b. Calculate the theoretical bending stress corresponding to each strain gage location by using the elastic bending equation  th  c. 3. Mc I NA Eq. 1 Compare the theoretical stresses calculated using Equation 1 with the experimental stresses calculated using the experimental strains and Hooke’s Law, and determine percent error. Theoretical Deflections: Calculate the theoretical deflections and compare them to the experimental deflections from the deflectometer and calculate percent errors. a. For the case with two loads between the supports (Fig. 2a), the equation for theoretical mid-span deflection is Δ = Pa(8a2 + 12ab + 3b2)/48EI 43 b. For the case with loads on the overhangs (Fig. 2b), the equation for theoretical mid-span deflection is Δ = Pab2/16EI 4. Plot the theoretical deflections from your calculations on the same graphs as your experimental load versus deflection plots. Discuss your observations. 44 X. Lab #6 Hot Mix Asphalt Superpave Volumetric Design and Compaction Tests A. Objectives: 1. To familiarize the student with the general characteristics of Hot Mix Asphalt (HMA) concrete and with the Superpave method of HMA mix design, and laboratory test methods for compacted bituminous specimens. 2. To perform standard laboratory tests on compacted HMA mixtures to determine the effect of varying design mixes and materials on the degree of compaction and percent air voids in compacted bituminous samples. B. References: AASHTO T166 Bulk Specific Gravity of Compacted Hot Mix Asphalt Mixtures Using Saturated Surface-Dry Specimens, American Associated of State Highway and Transportation Officials PA Test Method No. 715 Determination of Bulk Specific Gravity of Compacted Bituminous Mixtures, Pa. Dept. of Transportation, June 2003. ASTM D6925-07 Standard Test Method for Preparation and Determination of the Relative Density of Hot Mix Asphalt (HMA) Specimens by Means of the Superpave Gyratory Compactor ASTM D2041-03a Standard Test Method for Theoretical Maximum Specific Gravity and Density of Bituminous Paving Mixtures ASTM D2726-05a Standard Test Method for Bulk Specific Gravity and Density of NonAbsorptive Compacted Bituminous Mixtures ASTM D3203-05 Standard Test Method for Percent Air Voids in Compacted Dense and Open Bituminous Paving Mixtures C. Background: Asphalt pavement is made from aggregates (stone, sand or gravel) using asphalt cement (a derivative of crude oil refining) as the “glue” or binder. It is produced by heating asphalt cement and mixing it with aggregates and mineral fillers. The resulting product is referred to as “hot mix asphalt” or “HMA.” Typical proportions are 94 to 96 percent aggregate and 4 to 6 percent asphalt cement. Asphalt pavement is built in layers. The first step is to remove topsoil and compact the earth. Then, a base that will help to carry the load is placed and compacted. (The base 45 may be constructed solely of stone, or it may include both stone and asphalt.) Two or more layers of hot mix asphalt are then placed and compacted. Pavement thickness is chosen based on what kind of stresses the pavement must withstand (trucks vs. cars) and other factors such as soil conditions and climate. It also depends on the materials used in the asphalt and what materials might be present in the lower layers of the pavement. Whenever asphalt pavement is placed and compacted, there will be a certain amount of air voids, the small pockets of air between the coated aggregate particles. The amount of air voids is expressed as a percent of the bulk volume of the compacted paving mixture. Efforts should be made to keep compacted air voids between 3% and 8%. Once voids reach 8% or higher, the voids become interconnected and allow air and moisture to permeate the pavement which reduces pavement durability. On the other hand, there must be sufficient air voids to allow a slight amount of added compaction under traffic loading without bleeding and loss of stability that would lead to pavement rutting. If air voids fall below 3%, there will be inadequate room for expansion of the asphalt binder in hot weather and when the void content drops to 2% or less, the mix becomes plastic and unstable. Mixes are usually designed for 4% air voids (e.g. 96% compaction) in the lab and compacted to at least 93% (e.g. less than 7% air voids) in the field. PennDOT acceptance standards are based on an optimum 4% air voids (96% compaction) in laboratory specimens for approved mix designs, with an acceptance range of 92% to 97% compaction (from 8% down to 3% air voids) in field samples. When samples from the field are tested and fall outside this acceptance range, penalties are imposed on the contractor (i.e. contractor doesn’t get paid full price for the asphalt that was placed or contractor may be required to remove and replace the asphalt). The objective of HMA mix design is to develop an economical blend of aggregates and asphalt. Historically asphalt mix design has been accomplished using either the Marshall or the Hveem design method. The most common method was the Marshall, which had been used by about 75% of the Departments of Transportation (DOTs) throughout the US and by the Federal Aviation Administration (FAA) for the design of airfields. Then in 1995, the Superpave mix design procedure was introduced by the Federal Highway Administration. Superpave builds on the knowledge from Marshall and Hveem procedures. The primary difference between the three procedures is the machine used to compact the specimens and the tests used to evaluate the mixes. Superpave procedures are used by DOT’s throughout the US for the design and quality control of HMA highway projects. No matter which design procedure is used, the HMA mixture that is placed on the roadway must meet certain mix requirements:  Sufficient asphalt to ensure a durable, compacted pavement by thoroughly coating, bonding and waterproofing the aggregate.  Enough stability to satisfy the demands of traffic without displacement or distortion (rutting).  Sufficient voids to allow a slight amount of added compaction under traffic loading without bleeding and loss of stability. However, the volume of voids should be low enough to keep out harmful air and moisture. 46  Enough workability to permit placement and proper compaction without segregation. The Superpave design method for hot mix asphalt (HMA) consists of three phases: (1) materials selection for the asphalt binder and aggregate, (2) volumetric proportioning of aggregate and binder, and (3) evaluation of the compacted mixture based on specimens compacted using the Superpave gyratory compactor (SGC). The SGC compacts the asphalt mixture into a mold using a gyratory motion that causes a kneading action. The appropriate number of gyrations varies for different highway projects, and is determined based on traffic and project site high temperature conditions. As traffic and temperature increase, the number of required gyrations at which the asphalt mixture is evaluated also increases. There is no general strength test to complement the volumetric mixture design method. Industry has expressed the need for a simple strength test to complement the Superpave volumetric mix design method and ensure reliable mixture performance over a wide range of traffic and climatic conditions. So far, no simple strength test has been adopted for use with the Superpave design method. D. Materials: Several samples of HMA mixtures compacted in a Superpave Gyratory Compactor (SGC). The instructor will provide the theoretical maximum specific gravity (Gmm) for each sample. Gmm is the ratio of the weight of a given volume of voidless (no air voids) HMA at a given temperature to the weight of an equal volume of water at the same temperature. E. Equipment: 5 kg balance or scale fitted with a suspension apparatus and holder to permit weighing the specimen while suspended in water, water bath equipped with overflow outlet for maintaining a constant water level, oven for drying specimens. F. Procedure: (based on AASHTO T166 Test Method A) For each specimen 1. Weigh and record the dry mass. Designate this mass as “A”. 2. Fill the water bath to overflow level with water at 77o F (25o C) and immerse the specimen for 4 minutes. 3. Weigh and record the submerged weight, with the specimen in the water bath and using a suspension apparatus and holder. Designate the submerged weight as “C”. 4. Remove the sample from the water and quickly surface dry with a damp towel. 5. Weigh and record the mass of the saturated surface dry (SSD) specimen. Designate this mass as “B”. Any water that seeps from the specimen during the weighing operation is considered part of the saturated specimen. Because the 47 SSD mass is more difficult to properly measure, repeat this measurement several times until you get readings that are in reasonable agreement with each other. G. Measurements and Calculations: 1. Prepare a data table to record the following information for all specimens tested; data tables will be shared among all groups by posting to shared files on the Campus Cruiser course web page. Group ID: Specimen ID: Base or Top course; Dry Mass, “A” (kg): Saturated Surface Dry Mass, “B” (kg): Submerged Weight, “C” (kg): 2. Perform the following calculations for each specimen tested in lab (include data from all lab groups so that means and standard deviations can be calculated). a. Calculate the Bulk Specific Gravity Gmb of the asphalt mixture, which is defined as the ratio of the weight in air of a unit volume of a permeable material at a given temperature relative to the weight in air of an equal volume of water at the same temperature. The Bulk Specific Gravity can be calculated from Gmb = A/(B-C) where Gmb = A= B= C= Bulk Specific Gravity Mass of dry specimen in air, g Mass of SSD specimen in air, g Weight of specimen in water, g b. Calculate the Percent Water Absorbed (by volume) = 100 x (B-A)/(B-C) If the percent water absorbed is greater than 3 percent, Bulk Specific Gravity should be calculated using paraffin-coated specimens. Indicate whether or not your specimens are acceptable for percent water absorbed, or if they should have been paraffin-coated. c. Calculate the Percent Compaction and Percent Air Voids for each sample Percent Compaction = Bulk Sp. Gravity/Max. Th. Sp. Gravity = 100 x Gmb/Gmm Percent Air Voids = 100 – Percent Compaction 3. Calculate averages and standard deviations using data from all samples of the same mix design. Compare average results from different design mixes. Do the samples fall within PennDOT’s acceptance criteria? 48 Relationship Between Turbidity and Suspended Sediments for Ridley Creek ENGR 111-D1 (C.E. Lab #1) Conducted: 10/3/98 Submitted to: 10/10/98 Joe Smith Lab Group Members: John Doe Mary Jones Abstract: The objective of this experiment was to develop a predictive relationship between turbidity and suspended sediment (SS) concentrations following storm events for Ridley Creek. Since the turbidity of the stream can be continuously measured during a storm, the turbidity measurements can be used to estimate the suspended sediment concentrations washed into the stream during rain storms. Water quality samples were collected from Ridley Creek during three storms in 2001 and analyzed for turbidity and SS concentrations. Linear regression was used to develop a statistically significant linear relationship for predicting SS as a function of turbidity. 2 Introduction Runoff from storm events can wash large quantities of sediment into streams. Fish and other aquatic life may be adversely impacted under high sediment concentrations. The objective of this experiment was to develop a predictive relationship between turbidity and suspended sediment (SS) concentrations for Ridley Creek. Since the turbidity of the stream can be continuously measured, the turbidity measurements can be used to estimate the suspended solids concentrations washed into the stream during the entire storm. Water quality samples were collected from Ridley Creek during three storms in 2001 and analyzed for turbidity and SS concentrations. The data were graphed and analyzed to find the best equation to describe the relationship between sediment concentrations and turbidity for Ridley Creek. Background Turbidity is cloudiness in the appearance of a liquid caused by solids, particles and other pollutants. Turbidity is not color related, but relates rather to the loss of transparency due to the effect of suspended sediment (SS), colloidal material, or both. A body of water, such as a lake, is a natural example of turbidity. All of us have seen lakes that are very clear to the eye, and are sometimes fascinated by the depth to which one can see. On the other hand you find 'murky' waters where you couldn't see your hand at arm's length. Typical sources of turbidity in drinking water include waste discharges, algae and aquatic weeds, humic acids and other organic compounds resulting from decay of plant 3 matter, high iron concentrations, and runoff from watersheds flushing sediment into a stream. Turbidity measurement provides an indication of the clarity of water and water quality. The nephelometric turbidimeter, which measures turbidity by the light scattered at 90 degrees to the incident beam, is the preferred method for measuring turbidity because of its sensitivity, precision, and applicability over a wide range of particle sizes and concentrations. Thus, Suspended sediment (SS) load in streams and rivers include organic and inorganic particles that are suspended in and carried by the moving water. Turbidity is generally a much better predictor than water discharge for estimating suspended sediment (SS) concentrations in rivers. Although it is now possible to collect continuous turbidity data even at remote sites, sediment sampling and load estimation are still conventionally based on water discharge. With frequent calibration, the relation of turbidity to SS can be used to estimate suspended loads more efficiently. The sampling can be automated using a programmable data logger which signals a pumping sampler to collect SS specimens at specific turbidity thresholds. The approach has potential for monitoring any water quality constituent whose concentration is better correlated with an easily measured (in situ) parameter, such as turbidity, than with water discharge. Methods and Procedures Water quality samples were collected from Ridley Creek near the Widener campus every 15 min. during three storms in 2001. The 1 L samples were immediately delivered to the environmental lab and analyzed for SS and turbidity using procedures published in 4 Standard Methods for Water Quality Analyses (2000). Turbidity measurements were conducted on a Hach 1000P portable nephelometric turbidimeter which was calibrated before each use. The experimental data were then graphed and a linear regression equation was developed using Excel. Results and Discussion The results of the SS and turbidity measurements are listed in Table 1 for each storm event. Several of the turbidity samples exceeded the upper measuring limit of the turbidimeter (indicated as “>ML” in Table 1), and these data were not used in the remaining analyses. Figure 1 shows the graph of SS vs. turbidity for all the measurable samples, and it is clear that a linear relationship exists between turbidity and SS. Linear regression was applied to the SS and turbidity data using Excel, and a statistically significant relationship was developed. Table 2 summarizes the results of the regression analysis, and Equation 1 shows the predictive equation for SS as a function of turbidity. SS = 1.56 NTU – 3.1 EQ. 1 where: SS = suspended solids concentration in mg/L NTU = turbidity measurement This equation can be used to predict SS concentrations based on turbdity measurements for ...
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Hot Mix Asphalt Superpave Volumetric Design and Compaction Tests
ENGR 111-D1 (X. Lab #6)
Conducted: 27/04/2018
Submission date: 27/04/2018

Name:
Lab Group Members:

Abstract:
Asphalt Superpave volumetric design and compaction tests give engineers’ vital data of
what type of asphalt they should use in specific climatic and traffic conditions. The main objectives
of this experiment was to (1) To acquaint student with the most universal characteristics/features
of Hot Mix Asphalt (HMA) concrete and with the Superpave method of HMA mix design, and
laboratory test methods for compressed bituminous specimens and (2) To execute a
standard/measure laboratory tests on compacted HMA mixtures to find out the effects or results of
altering design mixes and materials on the level of compression and percent air voids in pressed
together bituminous samples. The specimens/samples were registered for their dry weight, weight
submerged under water, and the saturated surface after drying. The obtained results showed that
the top-virgin samples were the lightest specimen submerged under water, and the base-virgin
specimens were found to be the heaviest of all. The final outcomes were used to compute the bulk
gravity of the used asphalt mixture, the percentage water absorbed, percent concretion, and the
percentage air voids for each of the specimens. The standard deviation and the average of the same
specimens were employed to compare the average results from the different design blends/mixes
and unfold if the specimens were within the PennDOT’s adoption standards.

2

Introduction
Hot mix asphalt is a material that is consistently and frequently used by engineers in the
construction of roads and highways. Different hot mix asphalt mixes are used according to
different traffic and climates. When designing a road in a particular area an engineer should put
into account the compaction and air voids percentage as the main factors. The main objectives of
this experime...


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