3 PRE-LAB WORK - Preparations before the test Before the test, each student must complete the work described in Sections 3.1 and 3.2. 3.1 BACKGROUND PREPARATIONS. Complete the background preparations

for the test and answer the questions below (keep all answers short and sweet; just a paragraph or a list of bullet points is fine, as long as you make your answer clear and intelligible). Read through the whole of the Lab Script and the Lab Report template. Watch the following set of videos on You Tube, titled collectively: Bare Essentials of Reinforced Concrete (https://www.youtube.com/playlist?list=PLXdvc710lmyJ6VY6QKtKfhpBzAzj3WpM_). These are also available on VITAL CIVE241. Answer the following questions on these videos (make notes of your answers while watching the videos). The questions follow the order of the videos on YouTube. Video title What is Reinforced Concrete? - Bare Essentials of Reinforced Concrete with Prof Tim Ibell Pt1 Reinforced concrete beam resisting bending - BE of Reinforced Concrete with Prof Ibell Pt2 Compatibility of steel and concrete - BE of Reinforced Concrete with Prof Tim Ibell Pt3 Durability of Reinforced Concrete - Bare Essentials of Reinforced Concrete with Prof Tim Ibell Pt4 Resisting Shear - Bare Essentials of Reinforced Concrete with Prof Tim Ibell Pt5 UNIVERSITY OF LIVERPOOL Q No. Questions A B C D E F G Concrete has very poor tensile strength properties. How do structural engineers overcome this problem? How does the failure of an under-reinforced RC beam differ from an over-reinforced RC beam? Which type of failure is better for RC beams in structures? What are the two types of bond mechanisms that join reinforcing steel and concrete in RC beams? Apart from its strength, give three good reasons why steel is used to reinforce concrete structures. What are the two key reasons for adequate concrete cover to steel reinforcement? Without shear links in an RC beam, would a shear failure be gradual or brittle? Page 5 Visit the Health and Safety Executive (HSE) website (http://www.hse.gov.uk/) and search for 'cement' click through and read the various documents on this topic. The items on dermatitis are unpleasant but you should still look at these. Make sure that you: (i) download and read the HSE Information Sheet No.26 on cement (CIS26 - cement) and (ii) watch the Dermatitis video (this is also available on CANVAS CIVE241). Health, safety and wellbeing See paragraphs above D. E 3.2 THEORETICAL CALCULATIONS. Carry out sufficient theoretical calculations to predict the performance of the RC beam prior to the lab testing taking place. Throughout this lab, when doing any calculations: (i) ignore the self-weight of the RC beam and (ii) do not apply any load factors to the applied loading of the RC beam. It is reasonable to assume that the effect of the self-weight is only small and its presence in calculations tends to make the calculations more complicated and harder to interpret. We can safely ignore it for the purposes of this learning experience. In design, it should be accounted for. A, B and C. F. RCB Lab Script v1/ CIVE241 Q No. H I Questions What does it feel like to get dermatitis? You are the contractor on an in situ multi- storey reinforced concrete framed building. Give two ways that you can prevent your workers coming into contact with cement. Draw the (A) bending moment diagram (BMD), (B) shear force diagram (SFD) and (C) the deflected shape of the RC beam supporting the load arrangement shown in Figure 1. Assume that the testing machine is applying a force of 10kN to the RC beam (therefore each load F is 5 kN). As noted above, do not factor up this load of 5kN. Estimate, by calculation, the theoretical cracking bending moment Mor of the RC beam and the corresponding load For. When doing this, do not apply the materials factors of safety for the tensile strength of the concrete (fctm and fctm,fl). UNIVERSITY OF LIVERPOOL Calculate the maximum theoretical applied force that can be applied to the RC beam (giving two point loads of Fapp,el) before the steel reinforcement reaches its yield stress. In doing this calculation, make use of the material safety factors for both steel and concrete (1.15 and 1.5 respectively). Until the loading to the beam reaches this point, the steel reinforcement will behave elastically. With greater loads, plastic deformation of the steel reinforcement will take place. [Note: during the actual lab test, the loading to the RC beam will be taken to around 10kN (or similar value, at the discretion of the Lab Technician) before being cycled back to zero to investigate the elastic properties of the RC beam. After this exercise the loading to the RC beam will be increased gradually until the beam fails.] At the point that Fa is reached, the beam will be at its ultimate moment capacity Mu which can be calculated from first principles or can be calculated from the equations in Appendix A. State the theoretical ultimate moment capacity M₁ of the RC beam. app,el Calculate VRd to demonstrate that the shear links will provide adequate shear resistance to prevent the RC beam from failing in shear even when the applied load reaches Fapp,el. In doing this calculation, do not apply a load factor to the applied Page 6 load. NOTES FOR THE PRE-LAB WORK 1. Marks are attached to the successful and timely completion of both the Lab Report and the Pre-Lab Work. All the work required in Sections 3.1 and 3.2 must be completed and presented to the lab demonstrator before the lab commences. 2. Students may not be allowed to participate in the test without showing the demonstrator that the tasks listed in Items 3.1 and 3.2 above have been completed. 3. At the start of the lab, a single mark of 10% of the assignment will be given on a pass/fail basis for the pre-lab work. If you have completed the pre-lab work, you will gain a mark of 10%. If you do not show that you completed the pre-lab work, you will be given zero marks. The quality of the pre-lab work will be assessed when the Lab Report is submitted and marked. 4. Conventions must be followed for drawing BMDs and SFDs. The bending moment diagram is drawn on the tension face of the member. The shear force is considered positive and the diagram is drawn above the datum where externally applied shear forces are clockwise in nature and internally resisting shear forces are anti-clockwise. So, for a simply supported horizontal beam with a central point load acting vertically downwards, the BMD would be drawn on the bottom of the beam and the left-hand side of the shear force diagram would be positive and drawn above the datum and the right-hand side would be negative and drawn below the datum. tve UNIVERSITY OF LIVERPOOL VALVE -ve 0 * RCB Lab Script v1/ CIVE241 BMD Draw on tension (KNM) face of element 0 SFD (KN) DEFLECTS SHAPE (no units) Figure 4 Sketches of BMD and SFD, etc. to illustrate conventions to be used in the Pre-Lab Work and the Lab Report Page 7 RCB Lab Script v1/ CIVE241 5. Note that the load F in Figure 1 is half the total load applied by the testing machine. 6. In Appendix 1 some relevant design equations are provided. You should also refer to your notes from lectures and the VITAL site for the module.