Wednesday, February 12, 2020

Fabrication of a Reinforced Concrete Beam Lab Report

Fabrication of a Reinforced Concrete Beam - Lab Report Example Thirdly this gives sufficient space for the main reinforcement to develop full stressing and strength, which consequently prevents slipping of the bars. Lastly a sufficient cover gives a smooth surface which improves the aesthetics of the component as well. 3. 4. Bar codes are on the schedule so that the reader must understand that how the steel bar is is to be bended and what angles and shapes are to be made. In addition to this the reader can easily calculate the length of the bar, and consequently by using the diameter and the type of bar the total weight of the bar can be calculated and finally the total weight of the reinforcement. 5. The cover can be maintained by different methods. One method can be made by placing Metal plastic tipped bar chairs under the reinforcement so that a specified height can be maintained between the bottom surface and reinforcement. Then another method is to give spacer blocks, these can be small marble pieces or concrete plates. Another method used for very heavy reinforcement is the employment of Plastic strip bar chairs. 6. a) coarse aggregate = 122.4 Kg b) fine aggregate = 81.6 Kg c) cement = 40 Kg d) water = 22 Kg 7. Water cement ratio of the concrete is (weight of water / weight of cement ) is w/c = 22/40 = 0.55 SSD or saturated surface dry is a condition of the aggregate when all the surface pores of aggregate are fully filled and there is no excess water on its surface. In addition no more water will be absorbed by the aggregate when immersed in water. This aspect is important because if the aggregate is not saturated then it will start absorbing the water of the concrete which was supposed to be consumed in the hydration of the concrete. If there is less water in the concrete than required the concrete will not acquire the desired strength and the concrete will have microscopic cracks further weakening the concrete and this will also disturb the desired water cement ratio. Then this state helps in finding the absorptio n value of aggregates and also the specific gravity of aggregate. Lastly the aggregate must be saturated surface dry as the dry surface will help and ensure a good bond between the concrete and aggregate. 8. A clean beam form is important because presence of any loose material will attach on the surface of the beam and when the beam is subjected to bending the concrete around this loose material and the loose material it self will spall off. Hence the cover would be compromised and there is a chance that the steel reinforced will be naked and prone to environment resulting into its rusting and corrosion. 9. The indication of completion of the compaction is that the firstly there is no decrease/ decay in volume or height of the concrete and the movement of aggregates due to vibration in the concrete will very low. In addition the final indication is that the water will come on the surface of the concrete and it must be noted that as soon as the water film appears on the surface of th e concrete the vibrator must be pulled out of the concrete or else the concrete will segregate, resulting into separation of cement paste and aggregate. 10. The compaction of concrete is very important for its acquisition of desired strength, In essence compaction is the process in which the entrapped air is released from the