Industrial waste without proper control may lead to contamination and cause environmental pollution. Transforming waste such as coal bottom ash (CBA) wastes into a sustainable construction material is so much help in reducing the waste in the surroundings and is also environmentally friendly. In this research, cement was replaced with CBA in the concrete to analyse the effect on concrete performance. Consequently, this project focuses on physical and mechanical properties of concrete before and after using CBA. In the design stage for concrete mixing, the ratio for raw materials selected was 1:1.35:3.2 for cement, sand, and aggregates, respectively (grade 25). Two different major categories of concrete were made and compared. The first category is ordinary concrete with control concrete mix (CM), while the second category is concrete which uses 5%, 10%, 15%, 20%, 25%, and 30% of CBA partial replacement in the volume of cement in the concrete mix. The samples we used in this research were cubes 100 mm x 100 mm x 100 mm prepared for the water absorption, density, and compression test. The workability of concrete containing CBA with fixed water quantity was lower corresponding to that of the control mix. The hardened concrete density was reduced, and the water absorption increased with an increased amount of ground CBA. The results for the compressive test of control samples are 22.940 N/mm at 28 days of curing, and the highest percentage was 10% CBA which is 28.28 MPa. Since the strength of the concrete with CBA is increasing so, modified concretes can be considered to use in construction.
