Abstract:
This study explores a sustainable approach to concrete production using recycled aggregates, fly ash and nylon fibre. Demolition waste served as coarse aggregate, fly ash replaced part of the cement, and nylon fibre reinforced the mix. Fourteen concrete batches were tested with varying fly ash (two and a half percent, five percent, seven and a half percent and ten percent) and nylon fibre (0.1 percent, 0.15 percent and 0.2 percent) contents. A standard 1:2:4 mix with a 0.55 water-cement ratio was used. The optimal mix, with two-and-a-half percent fly ash and 0.2 percent nylon fibre, showed improved compressive strength (4.4 percent and 15.6 percent) and tensile strength (twenty-four percent and thirty-four-and-a-half percent) compared to conventional and recycled aggregate concrete. Higher fly ash content reduced strength, and the absence of nylon fibre decreased tensile strength, emphasising the importance of reinforcement. This approach enhances concrete performance and supports more sustainable construction.