Structural Performance Assessment of Green Concrete: Partial Replacement of Fine Aggregate with Pond Ash

This study focuses on the structural behavior of reinforced concrete (RC) columns and slabs with partial replacement (0%, 10%, 20%, 30%, and 40%) of fine aggregates with pond ash (PA). In the first phase, the reinforced concrete columns and slabs were tested to verify their overall ultimate load capacities, failure modes, and load displacement behavior. To simulate the behavior of reinforced concrete columns and slabs under static loads, in the second phase, a nonlinear finite element analysis (FEA) was performed using the ANSYS software. Compared to the control mixture, the mixture with a PA replacement level of 20% proved to be the most promising by providing improved structural performance and crack resistance. This indicates that replacing sand with PA by approximately 20% can improve concrete strength and crack resilience. The experimental results were compared with finite element models, and a strong correlation was demonstrated by comparing the experimental data and FEA results, with average error margins of 5.4% and 6.7% for columns and slabs, respectively. Furthermore, the load-deformation behavior of the experimental tests and cracking modes agreed well with the finite element model. In summary, this research encourages the use of environmentally friendly building materials by highlighting the utility of PA as a fine aggregate, especially in areas with a shortage of natural sand.