CE337 Spring 24 - Sample Lab Report

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Michigan State University *

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(SAMPLE LAB REPORT FOR CE 337) Relationship between Water Cement Ratio and Slump CE 337: Civil Engineering Materials Fall Semester 2020 Group and Section Number Student Name and Signature Student Name and Signature Student Name and Signature Student Name and Signature Student Name and Signature (Missing signature will be assumed as no contribution and yields 0 grade) Friday, September 20, 2019

1 ABSTRACT An experiment was conducted to determine the relationship between the water cement ratio of a Portland Cement Concrete (PCC) mix and the resulting slump. Six PCC mix designs were obtained with water cement ratios varying from 0.3 to 0.6 by weight. All other PCC mix design parameters were held constant. The ASTM C143 slump test was run on all six mixes and the results were graphed. The resulting graph provided strong evidence of a direct non-linear relationship between the water cement ratio and slump.

2 *Note: Any italic font indicates further TA explanations of lab report guidelines. Students should NOT include sections like these in their lab reports. Essentially, the abstract condenses your entire report into one paragraph. The Abstract tells the reader:  Purpose of the experiment(s)  BRIEF summary of methods used (Note how the titles of procedures were often used in place of descriptions of procedures.)  Important results An informed reader should be able to understand the experiment and its results from reading the abstract alone. Abstracts are SHORT! They should consist of no more than 150-250 words. Therefore, students must employ concise statements. Do NOT use vague language. Whenever possible include specific information.

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3 GROUP ORGANIZATION Lab Participation  Bob measured concrete components  Frank mixed the six concrete mixes  Sue filled and rodded the slump cone  Jane recorded all laboratory measurements Report Participation  Bob wrote the abstract, group organization, and procedure section  Frank and Sue created the graphs and wrote the results and conclusion sections  The discussion questions were answered as a group  Jane wrote the discussion section and proofread the report  David Adams from the writing center reviewed the final report In the Group Organization section, please describe how the work was divided up and what each group member’s responsibilities were. Include the names of all proofreaders. If you took your report to the CE Writing Center, please include the name of the Writing Assistant who helped with the report. This section should be no more than one page. A list format is acceptable.

4 INTRODUCTION The ASTM C143 slump test can be used as an indicator of workability. Workability of concrete relates to how easily the concrete can be placed. Concrete mix designs often are required to meet certain specified slump values. The slump value requirements ensure the concrete can be properly poured and finished during construction. This experiment explored the effects of water cement ratio on the slump of a PCC mix design. The objectives of the experiment were as follows:  Determine whether a relationship exists between water cement ratio and slump of a PCC mix design  Obtain an equation that can be used to adjust the water cement ratio of a given PCC mix design such that the concrete produces the desired slump. This experiment is based on the ASTM C143 method of determining the slump of Portland Cement Concrete. In addition, the standard linear regression analysis procedures were applied by the Microsoft Excel to obtain the theoretical relationship between water cement ratio and slump. The introduction must do the following:  Define parameters and/or relationships you were asked to calculate and/ or develop.  Explain why the parameters are important, what they are used for, and why they pertain to civil engineering.  State the objective of the experiment(s). Treat the objective as if you are doing research for industry. What are they paying you to find out? Objectives should NOT be written as follows: “An experiment was performed to teach students about slump.”

5 METHODS AND MATERIALS Six Portland Cement Concrete (PCC) mix designs were used to explore the effects of water cement ratio on slump. These six designs were identical except for the water cement ratio. These designs can be found in Table 2 in the Appendix. Each of the designs were mixed and subjected to slump testing. The slump testing procedure requires the use of a slump cone, tamping rod, ruler, and a pan. The ASTM C143 specifications were used to determine the slump of several Portland Cement Concrete (PCC) mixtures. The ASTM procedure is summarized below: 1. Mix the concrete and dampen the mold. 2. After filling the mold in three layers, rod 25 times between each lift and remove excess concrete from top of mold 3. Lift mold off of concrete using a strictly vertical motion and measure the difference in height between the mold and concrete. As stated above, the mold must be filled in three lifts and rodded 25 times between each lift. Each lift should be approximately 1/3 the volume of the mold. During the rodding procedure, the rod should penetrate slightly into the previous lift. When removing the mold from the concrete, care should be taken to avoid lateral or torsional motions. After the mold is removed, the slump must be measured. (See Figure 1 below.) The slump is measured by placing the rod horizontally across the top of the metal mold. The vertical distance from the center of the slumping concrete to the bottom of the horizontal rod is measured using a ruler. The slump is then recorded to the nearest ¼ inch. This procedure was repeated for each of the six PCC mix designs. Figure 1: Diagram of slump measurement Slump Cone Concrete Ruler Rod

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6 Keep this part as brief as possible (DO NOT ALLOCATE MORE THAN ONE PAGE FOR EACH EXPERIMENT). Methods and Materials section should include:  A brief description of the key equipment used.  A brief description of the general experiment set up. This is especially important if you have a test repeated on several different materials. (See first paragraph of sample.)  The a brief procedures followed during the test.  ASTM designations of the procedures used.  Diagrams of special equipment

7 RESULTS The data collected from each of the six slump tests is shown below. Table 1 shows the water content of each tested mix and the experimentally determined slump. Table 1: Water Content and Slump Mix Water/Cement Ratio Slump (in) 1 0.30 1.20 2 0.35 1.75 3 0.40 2.50 4 0.45 8.00 5 0.50 5.50 6 0.60 10.00 Figure 2, displayed below, graphically demonstrates the experimentally determined relationship between slump and water content. Due to suspected error, the data point from mix 4 was excluded from the study. This point is shown on Figure 2, but was not factored into the experimentally determined relationship. Figure 2: Relationship between Slump and Water Content Figure 2 indicates that the slump and water cement ratio of these mixes are related by the following formula: 2 79.6 42.4 6.77 Y X X    (1) Where X represents the water cement ratio and Y represents the slump in inches. y = 79.616x 2 - 42.377x + 6.7677 0 2 4 6 8 10 12 0.25 0.35 0.45 0.55 0.65 Water Cement Ratio Slump (in) Experimental Data Points Suspected Error Point

8 The results section presents the experimental results. It includes the following:  Reduced data in clear, properly constructed tables and graphs.  Paragraphs that briefly describe the data contained in the table and graphs. The results section does NOT include discussion of the data. It merely presents the data to the reader. There are two important formatting issues with tables and graphs.  All graphs, figures and tables MUST be numbered and titled and centered. The title appears BELOW all graphs and figures. However, the title appears ABOVE all tables. (See sample above.)  ALWAYS include units on every table and graph.

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9 DISCUSSION The experimental results found in Figure 2 provide evidence of a direct non-linear relationship between the water cement ratio and slump. The results indicate that as the water cement ratio increases there is a corresponding increase in the measured slump. These results were not surprising. As the amount of water present in the concrete mix increases the mix becomes more fluid, and it begins to lose its internal cohesiveness. This results in increasing slump values. Equation 1 can be used to predict the effect of changing water cement ratio on concrete slump. When viewed in context with the other slump test results, the 4 th mix design had a higher slump than expected. The exceptionally high slump value caused suspicion about the accuracy of this particular data point. By excluding the 4 th data point from the study, the accuracy with which slump values could be predicted by the water cement ratios (or visa versa) was increased. Figure 3 in the Appendix shows the new trendline and equation that must be applied if data point 4 is not excluded. The resulting trendline does not fit as well to the experimental data. If the equation is used to predict either the slump or the water cement ratio, the mismatch between experimental data and the trendline will result in poorer predictions. The slump test is particularly prone to human error. The list below contains two human errors that could have been responsible for the unexpectedly high slump value of the 4 th data point. 1. Using too much water 2. Removing the mold incorrectly The use of incorrect amounts of water could occur in a variety of ways. The simplest explanation is that too much water was added due to incorrect measurement. Standing water in the equipment could also contribute to a cement mixture with too much water. Either of these errors would increase the actual water/cement ratio of the PCC mix. As this experiment demonstrated, increasing the water/cement ratio would lead to a higher slump value. The ASTM C143 procedure clearly states that the slump mold must be removed with no lateral or torsional motion. If the removal of the slump mold imparts torsional or lateral forces on the concrete, then the slump value obtained from this test may be greater than the true value. The false slump reading indicates a higher workability than the concrete actually has.

10 The discussion portion is the single most important section of your report. The discussion section must:  Explain and Analyze results  Discuss whether results are surprising/unexpected.  Discuss whether results are acceptable  Identify observed sources of error. (I.e. Human errors.)  Identify theoretical sources of error. (I.e. Flaws, limitations in the experiment itself)  Identify how the error may have affected the results. It is important for you as a student to demonstrate thoughtful analysis of the results. Discuss patterns you see in the data. When possible, compare your numbers to standard ranges given in your textbook or other reference materials. Are you in range? Does your data make sense? Does it comp are with what you know SHOULD have happened? If not… Think. What could have gone wrong? Are there problems with the procedure that would have led to poor results? If so, what are they? Did your group make mistakes in lab? THINK! What could have happened to influence your data? After you have some ideas on what could have influenced your data, Come up with ideas to explain HOW and WHY the error influenced your data. Did the error give you high values? Low values? Finally, is your data acceptable? Can people rely on it?

11 CONCLUSIONS The experiment yielded the following conclusions: 1. There is a direct non-linear relationship between the water cement ratio and the slump. 2. Equation 1 can be used to determine the water cement ratio required to produce the desired slump. It should be noted that Equation 1 has only been validated for the experimental mix design used in this experiment. It is likely that the relationship equation between the water cement ratio and slump vary for different PCC mix designs. The Conclusion section must: 1. List conclusions reached as a result of the experiment 2. Re-state any limitations, assumptions, or violations of assumptions that might qualify the conclusions. Do NOT include conclusions that are not supported by your data!

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12 REFERENCES (Follow one of the APA, MLA or Chicago citing guidelines, stick to one) 1. Mamlouk & Zaniewski, Materials for Civil and Construction Engineers. 1999, Addison- Wesley **References must be included anytime material other than lab notes are used. Be sure to reference the textbook if material is used from it.

13 Appendix Table 2: Experimental Mix Designs Mix Number Water (g) Cement (g) Coarse Aggregate (g) Fine Aggregate (g) 1 150 500 1500 1300 2 175 500 1500 1300 3 200 500 1500 1300 4 225 500 1500 1300 5 250 500 1500 1300 6 275 500 1500 1300 Figure 3: Relationship between Slump and Water Content when data point 4 is included. **The Appendix provides a place to put detailed information (raw data, calculations ect.) of interest to only a few readers. Please note that all tables and figures MUST be numbered and given a title. As always, tables are labeled on the top and figures are labeled on the bottom. Failure to follow this convention will result in loss of points. y = 30.471x - 8.3793 0 2 4 6 8 10 12 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 Water Cement Ratio Slump (in) Experimental Data Points Suspected Error Point

14 Sample Calculations A set of sample calculations showing one example of EVERY value which involved calculations (including simple arithmetic) must be submitted with the report and should be placed in the appendix. Sample calculations must be neat and they may either be hand-written on engineering paper or word-processed. Sample calculations are essential and a large reduction in the report grade will be given if calculations aren’t submitted according to these guidelines. In all cases the following format is to be used.  Include the equation written in general form.  Show the equation with your numbers substituted into it.  Clearly indicate the answer obtained from the equation. The following is an example: 1. Moisture Content Weight of Pan = 2.2 grams Weight of Pan + wet sample = 10.5 grams Weight of Pan + dry sample = 10.3 grams MC Pan wet sample ( ) Pan dry sample ( ) Pan dry sample ( ) Pan ( ) 100 %  Pan wet sample Pan dry sample Pan dry sample Pan MC 10.5 10.3 10.3 2.2 100  MC 2.469  % ANS

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15 Miscellaneous Report Guidelines 1. Each section of the report must be clearly identified and cannot be combined with other sections. 2. Do NOT skip any section. The penalty is severe. 3. Personal pronouns (I, we, you, me, ect.) should NEVER be used in a technical report. Students will be penalized for using personal pronouns. 4. Avoid tense changes. You may write in either past or present tense, but do not switch between the two. 5. Use double spacing, one side of the paper, same font type and size all on the reports. 6. Obey labeling conventions for tables and graphs. 7. Pages MUST be numbered!!!!!!!!!!!! Failure to do so will result in loss of points. 8. You will receive an electronic copy of this sample lab report. The TA’s suggest that you use it as a template for your own lab reports. However, do NOT include the italicized TA comments regarding report guidelines. * Grading will be done according to the Rubric posted on d2l website. Make sure you are aware of that and consult it while drafting the report.

CE337 Spring 24 - Sample Lab Report

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