Mechanical Properties of Cement Paste Containing Rice Straw Ash

Abstract

The purpose of this research was to study the mechanical properties of cement pastecontaining rice straw ash (hereinafter referred to as RSA) which was a by-product from rice strawburning in ferrocement incinerator. Physical and chemical properties of RSA were analyzed.Mechanical properties were obtained including normal consistency, initial and final setting times,compressive and splitting tensile strengths. An investigation on the expansion in water and dryingshrinkage were also determined. Water to binder material ratio was kept constant and equal to 0.4.The main variable was the percent of replacement of RSA in cement (0, 20, 40, 60 and 80%).The tested results showed that the strength of cement paste at 28 days can be developed byreplacing RSA in cement up to 40%. For other properties, when the percent of replacement ofRSA in cement increased, adsorption, normal consistency, final setting time, expansion in waterand drying shrinkage increased whereas initial setting time and normalized compressive strengthdecreased.