This task is about calculation and analysis of a beam, which is a compound bar made up of concrete and steel reinforcement. The specific activities completed involved relevant design calculations of a beam subjected to tensional force. The beam has a rectangular cross section and is reinforced with steel rebars. When the tensional force or load is applied at the centre of the beam, it causes deformation. The top part of the beam is under compression while the bottom part of the beam is under tension. The total elongation along the section of the beam under tension from the neutral axis has been calculated and the elongation diagram drawn. Findings show that elongation increases with the increase in distance from the neutral axis with maximum elongation occurring at the farthest distance from the neutral axis. The elongation was calculated using the maximum shear force.
The results obtained from the calculations were used to establish the most appropriate design of the beam i.e. its size including cross section, and size, spacing and number of steel reinforcement. Based on the unconventional size of the beam, the mix design of the concrete had to be modified. This was necessary because the comprehensive strength of the concrete had to be improved so as to make it more compatible with the tensile strength provided by the steel reinforcement thus increasing the overall strength of the beam. The size of the beam is 2.5" by 2.125" whereas the excavation of the beam is 3.5" by 3.125". After determining the concrete mix design that is suitable for the unconventional beam size, the weight of each component was also determined as follows: coarse aggregates – 6.4 lb, fine aggregates – 5.1 lb, cement – 2.1 lb and water – 0.83 lb.