Impact of Rice Husk Ash Properties on Concrete Strength: Experimental and Machine Learning Study

Abstract

This study explores the substitution of cement with rice husk ash in concrete, aiming to reduce the pollution and energy consumption caused by cement production. Through a series of experiments, including slump test, water absorption test, compressive strength test, and dynamic compression test, the effects of calcination temperature and average particle size of rice husk ash on concrete performance were evaluated. The findings indicate that the use of rice husk ash lowers slump while increasing the concrete’s water absorption capacity. With higher calcination temperatures, both compressive and dynamic compressive strengths initially improve, followed by a decline. Smaller rice husk ash particles lead to better performance in these strength tests. The ideal parameters identified were a calcination temperature of 650°C and a particle size of 5 µm. A machine learning approach, utilizing the eXtreme Gradient Boosting (XGB) model, was employed to predict dynamic compression strength, and the predictions were cross-referenced with experimental data. Shapley analysis was applied to assess the influence of individual variables on the strength outcomes. Results confirmed the accuracy of the XGB model, with an R2 value of 0.9435 and a mean absolute error (MAE) of 2.29 MPa, with particle size showing a more significant impact on dynamic compressive strength than calcination temperature.