3. Submission Date and Procedure Upload to Turnitin link on module web by 23.55 9th March 2015. 4. Feedback on coursework Feedback will be via the submission link on the module web usually within 3 weeks of submission. 5. Module Learning Outcomes related to this coursework After the successful completion of this exercise you will be able to: ? Use laboratory data at an appropriate level of accuracy and interpret it in terms of underlying engineering principles. ? Present relevant information and analysis in a clear and unambiguous way. ? In response to a relevant engineering problem, carry out calculations that lead to a solution, at the level expected of a student on a career path to Incorporated (210CAB) or Chartered (211CAB) Engineer. 6. Aims and objectives The specific aim of this coursework is to undertake an investigation to validate the theory associated with concrete mix design, and the analysis and design of reinforced concrete beams. The objectives are: 1. Design and batch a normal concrete trial mix using the BRE method. The mix is then modified to produce a selfcompacting concrete (SCC), possibly with PFA as a partial cement replacement. 2. Perform standard workability tests and report results. 3. Cast a variety of concrete samples and perform standard tests on them to determine mechanical properties of the hardened concrete. 4. Re-design the non-SCC trial mix using the observed workability and strength results. 5. Analyse the concrete results for all mixes used in the exercise by the module cohort and draw conclusions on the efficacy of using partial cement replacement and self-compacting concrete to improve the sustainable use of concrete in practice. 6. Fabricate, cast and load-test a reinforced concrete (RC) beam. 7. Predict the load-deflection performance of the RC beam from established theory and compare the results with those achieved, drawing conclusions on the validity/limitations of the established theory. 7. Procedure All students should independently prepare a mix design and check against those from other members of their group. Any inconsistencies should be investigated and resolved so that the group has a definitive mix design before attending the laboratory session. If the group does not do this they will lose the marks allocated for that part of the assessment and an alternative mix will be provided for them to use. C O V E N T R Y U N I V E R S I T Y Page 2 of 9 7.1 Health and Safety risk management in laboratory activities The main risks that we are aware of are as follows. If you become aware of another risk you should advise the supervising staff member. Loose clothing and long hair can get caught in machinery. Do not enter any part of the lab where the overhead crane is being used. The concrete moulds are heavy, especially when full. Take special care not to drop them. Do not attempt to carry a full mini-beam mould on your own. The noise from the vibrating table is intense. Wear ear defenders if you use it for more than two minutes. Do not use any of the machinery without a trained staff member to help you. Minimise skin contact with cement. Wash off all splashes immediately after the lab. The water in the curing tank is very alkaline. If you have to reach into it for your samples you should use the glove and wash your hands afterwards. You must observe the following mandatory precautions ? Do not use lab equipment without the specific authority of the supervising academic staff member. ? Wear strong footwear “ with reinforced toe-caps (you must bring these with you to the lab). ? Gloves are available and must be worn in the casting area ? Safety Goggles are available and must be worn in the casting area. 7.2 Trial mix design Design a 0.035 m3 trial mix to the following specification: Characteristic strength: see Table 1 Test age1: 28 days Percentage defectives: 5% Slump flow: see Table 1 (but assume a target slump of 100 mm for the design process) Cement: CEM1 class 52.5 Coarse aggregate: 10 mm maximum size, uncrushed Fine aggregate: 50% passing 600 ?m sieve Notes: 1 all students should design for 28 days even though some may test earlier or later depending on the rota. The mix should be designed to have a powder content of at least 500kg/m3. This may require the use of PFA, which may be assumed to develop 30% of the strength of an equivalent mass of cement (i.e. C+0.3F), up to a maximum proportion of 40% PFA. Table 1 Required characteristic strengths, slump flows and cement replacements for trial mixes and lab groups Group No. Characteristic strength (N/mm2) Slump flow (mm) Group No. Characteristic strength (N/mm2) Slump flow (mm) Group No. Characteristic strength (N/mm2) Slump flow (mm) CE1 20 600 CE11 20 650 CE21 20 700 CE2 25 600 CE12 25 650 CE22 25 700 CE3 30 600 CE13 30 650 CE23 30 700 CE4 35 600 CE14 35 650 CE24 35 700 CE5 40 600 CE15 40 650 CE25 40 700 CE6 45 600 CE16 45 650 CE26 45 700 CE7 50 600 CE17 50 650 CE27 50 700 CE8 55 600 CE18 55 650 CE28 55 700 CE9 60 600 CE19 60 650 CE29 60 700 CE10 65 600 CE20 65 650 CE30 65 700 Page 3 of 9 7.3 Concrete Casting Lab Before starting the laboratory work all members of the group should agree on a trial mix design having designed the mix individually. Batch and mix the required volume of concrete using the pan mixer. Measure the workability of a sample of the concrete using the slump test detailed in BS EN 12350-2:2009 Testing Fresh Concrete, Part 2: Slump test. Return the sample to the pan mixer and add superplasticizer and VMA compounds in accordance with the manufacturers instructions to produce the Self-Compacting Concrete (SCC) mix. Record the amounts of each compound added. Measure the workability of the SCC mix using: Slump flow (BS EN 12350-8:2010 Testing Fresh Concrete, Part 8: Self-compacting concrete “ Slump flow test) V-funnel (BS EN 12350-9:2010 Testing Fresh Concrete, Part 9: Self-compacting concrete “ V-funnel test) L-box (BS EN 12350-10:2010 Testing Fresh Concrete, Part 10: Self-compacting concrete “ L-box test) Report and record the test results in accordance with BE EN 12350. Make the following concrete test samples: 3 No. 100 mm cubes 3 No. 100 mm diameter, by 200 mm long cylinder Using the pre-bent reinforcement bars, links, tying wire and spacers provided, make up a reinforcement cage to the bar schedule drawing provided in the lab and place in the 1.5 m by 100 mm by 200 mm reinforced concrete beam mould (for use in the RC beam lab). Take care to ensure that the reinforcement cage is placed the correct way up in the mould and that the lifting hooks are securely fastened to the top of the cage. Record the bar sizes and spacing, and dimensions of the spacer blocks used to provide the concrete cover to the main steel bars. Demoulding and curing The moulds for all samples except the large beam must be struck after 24 hours. All students (except part-time undertaking their lab in the Xmas study break) should go to the laboratory to do this. Samples must be covered with polythene when cast and removed from the moulds. All specimens must be indelibly marked with the group number and date of casting, and placed in curing tanks. All moulds must be cleaned and lightly oiled for re-use. Failure to do this will result in test samples being destroyed and a mark of zero being awarded as a result. 7.4 Concrete Testing Lab (typically 4 weeks after casting but will vary depending on the rota) Determine the wet mass of each cube and cylinder. Test the cubes and cylinders in compression, recording the maximum load for each. The test machine output will be uploaded to the module web. Download the output file for your group and use it to determine the compressive strength, Elastic modulus and the rate of loading for each test. The test machine takes 10 readings every second so a column for time may be added to the spreadsheet. The rate of loading is obtained by plotting the load (on the y-axis) against time (on the x-axis) and finding the gradient. The Elastic modulus in compression is obtained by plotting the load (on the y-axis) against displacement (on the x-axis) and finding the gradient (converting to stress and strain. 7.5 RC beam Testing Lab (typically 4 weeks after casting but will vary depending on the rota) Set up the beam as shown in the Appendix and take zero demec and deflection gauge readings. Record the positions of the demec points and ensure that the load is applied at 1/3rd span positions and that the deflection is measured at midspan. Load the beam in equal increments of 3 kN up to a load of 30 kN. At each load increment record demec and deflection. Note the load at which cracks first appear, their length and direction in the beam for each load increment. Page 4 of 9 Continue to apply the load in 1 kN increments measuring deflections only. When the deflection begins to show large increases, remove the deflection gauge and load to failure. Record the failure load and carefully observe and record the mode of failure. Photographs may be used to record your observations. 7.6 The Report Experimental method Note any variations in standard test methods (sample testing) or those stipulated in this document (RC beam test) that may be the cause of any observed discrepancies in your results. Results and Analysis For the casting and sample testing: ? Present the results from the mix design and workability tests (casting lab), density and compressive tests (testing lab) for your group. Do not quote results without explaining how they have been obtained. ? Enter your results into the shared results spreadsheet (link on module web) within 1 week of completing the testing lab. Appendix A shows the results that are needed. ? Select any 1 of the 3 slump flow workability values used. Plot graphs of PFA content vs. cube strength, and cement content vs. cube strength, for all mixes with the same workability. ? Plot a graph of slump flow vs. cylinder strength for all mixes with the same characteristic strength as your group. For the RC beam test: ? Present the load, deflection and demec readings in an appropriate format along with any pertinent additional information for the test. ? Plot a graph of load vs. mid-span deflection. Annotate this graph with the loads at which major crack developments and increased deflection were observed and when the deflection gauge was removed. ? Plot the strain distribution across the depth of the beam for every 6 kN interval. ? Plot a graph of load v maximum compressive stress in the concrete using an appropriate value for Elastic modulus from the sample tests (or Table 1 in Appendix B). ? Determine the theoretical mid-span deflection, and add it to the graph of load vs. deflection. ? Using the EC2 stress block approach, calculate the theoretical ultimate load for your beam (bending and shear). Assume any values that you have not obtained, citing references. See Appendix B for further information to assist in the preparation of the report. Discussion For the casting and sample testing: ? Compare all of the results obtained including workability, density, standard deviations, compressive strengths and elastic modulus values with those expected (from cited reference sources or from your calculations) and discuss the source of any discrepancies. Your expected values must be specifically for the mix you have used. General references are not appropriate. The loading rates are not results but they may affect the results. They should be compared with the values in the relevant standard and the effect of any differences should be discussed with the relevant test. ? From the PFA vs. strength, and cement content vs. strength graphs describe the relationships and what this shows regarding the sustainable use of PFA as a cement replacement material. ? From the slump flow vs. cylinder strength graph describe the relationship and what this shows about the influence of superplasticiser on the compressive strength of concrete. Page 5 of 9 Mix Re-design: For your original mix (before superplasticiser and VMA were added), re-design the mix in order to achieve the design specification “ adjust water content, cement content (or cement and PFA), and estimated wet density. Do not forget to include the effect of any changes to the w/c you may have made by increasing or reducing your design water content during mixing. If your mix segregated or the workability was incorrect you should suggest new quantities for admixtures. You should explain your mix re-design in this section of the discussion. For the RC beam test: ? Compare your actual vs. theoretical results. Describe any discrepancies with reference to any assumed values or assumptions in the theoretical calculations. Consider in particular the apparent location of the neutral axis and the mode of failure. ? State, with justification, if your beam was œunder-reinforced or œover-reinforced, and the implications for the mode of failure. 8. Submission Requirements Your report should have the following format and A4 page limits: Title Page 1 Summary 1 List of Contents 1 List of Figures and Tables 1 Introduction 1 Experimental Method 1 Results and Analysis 10 Discussion 5 Conclusions 1 References 1 9. Marking Scheme / Criteria: This coursework constitutes 20% of the marks for the module and is an INDIVIDUAL exercise even though the laboratory work was done in groups. Ensure that you submit an individual report of your own work. The following marking scheme will be used: Item Proportion of mark (%) Mark range (%) 0 “ 39 40 “ 59 60-79 80-100 Results and Analysis 50 “ “ “ “ Mix design 4 Casting and sample testing 10 Graphs from shared group results 12 RC-beam test 12 RC-beam theoretical values 6 RC-beam ultimate load 6 Discussion 30 “ “ “ “ Casting and sample testing 8 Shared group results 8 Mix re-design 6 RC-beam test 8 Quality of report presentation Academic writing in summary, introduction & conclusions. Tables, figures, calculations. Correct referencing. Page limit, report structure. 20 Page 6 of 9 The following marking criteria will be used: Mark range Guidelines 80 “ 100% The report contents are entirely relevant and demonstrate an excellent understanding of theories, concepts, issues and methodology, as appropriate. There will be evidence of wide-ranging reading and/or research beyond the minimum recommended. The report will be written and presented in a clear, well-structured way with clarity of expression. There is evidence of a high degree of independent analytical and critical skills being employed. 60 “ 79% The report demonstrates a good understanding of theories, concepts, issues and methodology, as appropriate. There will be few, if any significant errors. Little irrelevant material has been presented. There will be evidence of reading beyond the minimum recommended where appropriate. The report will be well organised, clearly written and presented. There is some evidence of independent analytical and critical skills being employed. 40 “ 59% Demonstrates a reasonable understanding of the issues but the report is incomplete with substantial errors or misunderstandings. Some evidence of reading/research beyond that recommended may be present. Some inclusion of irrelevant material. May not be particularly well-structured, and/or clearly presented and is likely to contain a poor standard of English. 30 “ 39% 0 “ 29% Inadequate answer with little relevant material and poor understanding of theories, concepts, issues and methodology, as appropriate. Fundamental errors and misunderstandings will be present. Material may be largely irrelevant. Poorly structured and poorly expressed/presented using a poor standard of English. Clear failure to provide answer to the assignment. Little understanding and only a vague knowledge of the area. Most of the material presented is irrelevant. Contains serious and fundamental errors that demonstrate a lack of understanding. Virtually no evidence of relevant reading/research. Poorly structured and inadequately expressed/presented consisting of extremely short answers, and in note form only or very poor English. Page 7 of 9 Appendix A “ Results Sheet to be completed on the shared results spreadsheet (see link on Module web). Design Specification Group Number Characteristic Strength (N/mm2) Target slump (mm) 100 Target slump flow (mm) Mix design used Cement (kg) PFA (kg) Water (kg) Fine aggregate (kg) Coarse aggregate (kg) Trial mix Superplasticiser (g) VMA (g) Actual water used (kg) Workability tests Slump (mm) Slump flow (mm) d1 d2 L box (mm) H1 H2 V funnel flow time (s) Hardened concrete density test Cube mass (wet) (kg) Cylinder mass (wet) (kg) Strength tests* Age at testing (days) Cube strength (kN) Cylinder strength (kN) Loading rates Cube (N/mm2/s) Cylinder (N/mm2/s) Calculated strengths Compressive Cube strength (N/mm2) Compressive Cylinder strength (N/mm2) Calculated Elastic modulus Compression (Cube) (kN/mm2) Compression (Cylinder) (kN/mm2) Page 8 of 9 Appendix B “ RC beam test Plot values for every 6kN increments Use different colours Only use values of Ec from Table 1 if you are unable to determine it from your concrete sample test results. Page 9 of 9 NA Group No. CE21 Design Specification Characteristic strength (N/mm²) 20 Target Slump (mm) 100 Target Slump flow (mm) 700 Batch volume (m³) 0.035 Mix Design Cement (kg) 10.01 PFA (kg) 7.5 Water (kg) 7 Fine Aggregate (kg) 31 Trial Mix Superplasticiser (ml) 130 VMA (g) 3.6 Actual water used (kg) 6.1 Workability tests Slump (mm) 75 Slump flow d1 (mm) 700 Slump flow d2 (mm) 750 L-box H1 (mm) 103 L-box H2 (mm) 85 V-funnel flow time (s) 12.6 Dry Weight (g) Volume Depth (cm) Height (cm) Wet Weight (g) Hardened concrete density test Cube 1 mass (kg) 2.2284 Cube 1 mass (kg) 2228.4 10x10x10 1210.4 Cube 2 mass (kg) 2.2669 Cube 2 mass (kg) 2266.9 10x10x10 1232.5 Cube 3 mass (kg) 2.2577 Cube 3 mass (kg) 2257.7 10x10x10 1223.7 Cylinder 1 mass (kg) 3.5337 Cylinder 1 mass (kg) 3533.7 10 20.1 1933 Cylinder 2 mass (kg) 3.5343 Cylinder 2 mass (kg) 3534.3 9.9 19.9 1940 Cylinder 3 mass (kg) 3.5401 Cylinder 3 mass (kg) 3540.1 10 20.2 1934.7 Strength tests Age at testing (days) 21 Cube 1 max load (kN) 360.71 Cube 2 max load (kN) 385.18 Cube 3 max load (kN) 352.18 Cylinder 1 max load (kN) 210.74 Cylinder 2 max load (kN) 196 Cylinder 3 max load (kN) 197.6 Loading rates Cube 1 (N/mm²/s) 0.8 Cube 2 (N/mm²/s) 0.8 Cube 3 (N/mm²/s) 0.8 Cylinder 1 (N/mm²/s) 1 Cylinder 2 (N/mm²/s) 1 Cylinder 3 (N/mm²/s) 1 Calculated strengths Cube 1 (N/mm²) 36.071 Cube 2 (N/mm²) 38.518 Cube 3 (N/mm²) 35.218 Cylinder 1 (N/mm²) 21.074 Cylinder 2 (N/mm²) 19.6 Cylinder 3 (N/mm²) 19.76 Calculated Elastic Modulus Cube 1 (kN/mm²) Cube 2 (kN/mm²) Cube 3 (kN/mm²) Cylinder 1 (kN/mm²) Cylinder 2 (kN/mm²) Cylinder 3 (kN/mm²) Test code Group 21 Cylinder 3 Material type Specification and grade comment comment Time 11:37:30 Date 2/3/2015 Load 2000kN Disp 19.409 28.275 19.897 28.276 20.508 28.278 21.118 28.279 21.79 28.282 22.461 28.285 23.132 28.29 23.804 28.294 24.414 28.299 24.963 28.307 25.452 28.313 26.001 28.323 26.489 28.333 26.917 28.342 27.588 28.354 28.259 28.368 28.809 28.381 29.724 28.395 30.579 28.413 31.372 28.429 32.349 28.442 33.386 28.456 34.363 28.468 35.4 28.481 36.438 28.493 37.292 28.503 38.208 28.513 39.062 28.523 39.856 28.534 40.649 28.543 41.321 28.552 42.175 28.563 43.03 28.571 43.884 28.581 44.617 28.59 45.349 28.601 46.204 28.61 47.058 28.618 47.852 28.629 48.645 28.638 49.377 28.648 50.11 28.658 50.903 28.667 51.758 28.677 52.246 28.687 52.917 28.697 53.65 28.708 54.382 28.72 55.054 28.731 55.786 28.741 56.396 28.754 57.129 28.767 57.922 28.78 58.838 28.792 59.937 28.802 60.913 28.815 61.768 28.825 62.5 28.836 63.049 28.847 63.843 28.857 64.636 28.87 65.613 28.882 66.589 28.893 67.444 28.903 68.359 28.912 69.092 28.923 69.824 28.934 70.557 28.944 71.167 28.955 72.083 28.966 72.998 28.976 73.975 28.987 75.012 28.998 75.745 29.007 76.721 29.015 77.637 29.022 78.552 29.031 79.59 29.037 80.444 29.045 81.36 29.051 82.214 29.057 83.069 29.063 83.923 29.07 84.839 29.076 85.693 29.079 86.487 29.083 87.402 29.089 88.074 29.094 89.05 29.1 89.844 29.103 90.637 29.111 91.431 29.114 92.285 29.118 93.018 29.123 93.872 29.128 94.666 29.132 95.52 29.137 96.191 29.141 96.863 29.146 97.839 29.15 98.45 29.156 99.426 29.161 100.22 29.166 101.07 29.17 101.93 29.175 102.72 29.179 103.64 29.184 104.37 29.189 105.22 29.192 106.02 29.196 106.93 29.201 107.6 29.205 108.58 29.208 109.13 29.213 110.23 29.218 110.84 29.221 111.88 29.225 112.61 29.228 113.34 29.233 114.14 29.236 114.99 29.239 115.91 29.242 116.64 29.247 117.43 29.25 118.29 29.254 118.96 29.257 119.87 29.262 120.67 29.265 121.4 29.268 122.25 29.271 123.05 29.277 123.9 29.279 124.76 29.282 125.49 29.285 126.22 29.289 127.01 29.292 127.69 29.295 128.48 29.3 129.46 29.303 130.07 29.306 130.86 29.312 131.71 29.317 132.39 29.32 133.24 29.326 133.85 29.329 134.77 29.333 135.56 29.338 136.35 29.344 137.08 29.347 137.94 29.353 138.67 29.358 139.59 29.362 140.44 29.367 141.24 29.373 141.97 29.375 142.76 29.379 143.74 29.384 144.47 29.388 145.14 29.393 146.12 29.398 146.85 29.401 147.77 29.404 148.38 29.408 149.35 29.413 150.21 29.416 150.88 29.42 151.73 29.424 152.53 29.427 153.38 29.431 153.99 29.436 154.91 29.439 155.58 29.442 156.49 29.446 157.29 29.449 157.9 29.454 158.69 29.459 159.61 29.462 160.34 29.466 161.13 29.469 161.8 29.474 162.66 29.48 163.27 29.485 163.94 29.489 164.79 29.492 165.59 29.498 166.26 29.503 166.93 29.507 167.66 29.514 168.33 29.518 169.01 29.524 169.74 29.53 170.59 29.536 171.26 29.543 172.12 29.549 172.91 29.555 173.71 29.561 174.38 29.568 175.11 29.575 176.03 29.581 176.7 29.588 177.55 29.596 178.22 29.602 179.14 29.61 179.99 29.616 181.03 29.622 181.82 29.63 182.74 29.634 183.65 29.64 184.39 29.646 185.18 29.652 186.04 29.657 186.71 29.662 187.38 29.668 188.29 29.674 188.84 29.68 189.7 29.688 190.31 29.695 190.98 29.701 191.59 29.709 192.2 29.716 192.75 29.727 193.54 29.736 194.21 29.745 194.76 29.756 195.43 29.765 195.92 29.776 196.35 29.787 196.53 29.799 196.04 29.813 194.15 29.829 188.35 29.851 181.76 29.875 174.07 29.906 161.19 29.938 42.053 29.98 12.634 29.99 6.2866 29.95