Flexural Behaviour of a Reinforced Concrete Beam Blended with Fly ash as Supplementary Material

Two small-scale reinforced concrete beams, one made of ordinary Portland cement (NC) and the other blended with supplementary material using fly ash (SMFA), were investigated to gain insights into their flexural behaviour. Class F fly ash by 15 per cent of the mass of cement was added in the concrete mix of SMFA beam, enabling the reduction of cement usage. The specimens were designed under-reinforced having low steel bar ratio and were tested under four-point bending to failure. To ensure the beam failing in flexure, the M/Vd ratio of 3.2 was customary to allow the development of flexural cracks transpired over the centre span as the load further increased. Predictions incorporating manual calculation and computer simulation using Response-2000 were also performed and compared against the experimental data. The results showed that the NC and SMFA beams were generally equivalent in terms of load-deflection response, crack pattern, and mode of failure. Nonetheless, it should be marked that the load-carrying capacity of the SMFA beam was 22 per cent higher than that of NC beam, while the deflection of the SMFA beam was found to be significantly higher. Predictions from the manual calculation and computer simulation using Response-2000 were also in good agreement with the results obtained from the experiment.