Mechanical Performance Evaluation of M20 Concrete with Rice Husk Derivatives

Abstract

In the context of Nepal, rice production generates considerable amounts of agri cultural waste, notably rice husk. This study inspects the performance of M20 grade concrete incorporating rice husk and its derivatives, such as rice husk ash (RHA) and rice husk biochar (RHB), as partial replacement of cement by weight. A replacement level of 5% for each material was selected to evaluate its effect on the workability and mechanical properties. The slump test analysis revealed a minimal decline in workability due to the porous nature and water absorption capacity of the materials. The mechanical strength (compressive) results at 28 days exhibited the incremental improvement for mixes containing 5% RHA (28.1MPa) and 5% RHB (26.9 MPa) compared to the control mix (26.4 MPa), while a minimal reduction was noticed for the combined mix, as 15% in total replacement of cement by RH-derivatives (23.7MPa). The development in strength is assigned to the pozzolanic reaction of amorphous silica present in RHA, which assists in the formation of additional calcium silicate hydrate (C-S-H) gel. The presence of chemical bonds such as Si-O-Si bonds, which highlight the silica contribution to the concrete matrix at the time of hydration, can be analyzed by Fourier Transfer Infrared Spectroscopy (FTIR) analysis. The promotion of sustainable construction and efficient agricultural-waste management can be effectively achieved by using rice husk derivatives as supplementary cementitious materials. The study clarifies that the rice husk derivatives can be effectively utilized as supplementary cementitious materials (SCMs), promoting sustainable construction and efficient agricultural-wastemanagement.