Impact of WPSA and GGBS as a partial cement replacement on the hardening characteristics of cement concrete

The present study examines how the characteristics of hardened concrete are impacted by waste paper sludge ash (WPSA) and ground granulated blast furnace slag (GGBFS). In this experimental investigation, five mixes with maximal replacement levels of ordinary Portland cement (OPC) with WPSA and GGBS of up to 50% weight. The mechanical strength of hardened concrete specimens was determined using compressive and flexural strength only and compared to results obtained from ANSYS Workbench R 18.1. The loading conditions used for experimental setup and ANSYS analysis are same. The specimens were tested using the first center point crack loading. The study also explores comparison of experimental and ANSYS R 18.1 Workbench results to estimate the difference in accuracy. Due to the use of the various percentages of GGBS and WPSA, the relationship between compressive strength and design mix was found out to be not optimal. This study encompasses the use of ANSYS Work bench model. On the reference cube and beam, nonlinear FEM analysis revealed the same deformation values for RC (reference concrete) and CPG5 (50% OPC + 25% WPSA + 25% GGBS), indicating that other mixes are stiffer than RC and cube. Comparative study shows that the percentage error was about 5-7% in case of flexural and 0.5-3% in case of compressive. With WPSA's high water requirement, the mixtures became too permeable and sticky, making them challenging to compress. As a result, the minimum replacement of cement with WPSA gives maximum strength. Thus, the strength of CPG1, which replaces cement with 45% GGBS and 5% WPSA, is higher than that of standard concrete. Further research is needed before WPSA can be used extensively and mixed with different binder chemicals.