Effect of burning temperature on alkaline reactivity of rice husk ash with lime

AbstractThe rice husk ash (RHA) is a by-product of rice milling, being used as a soil stabiliser to build roads, an economical alternative with environmental benefits. A research of the influence of kind and temperature of burning on the reactivity of RHA and mixtures with sandy soil and lime was made. A no controlled temperature RHA and RHAs done with different controlled temperatures were used. X-ray diffraction analyses and loss on ignition tests were carried out on RHAs. X-ray diffraction analyses, unconfined compressive strength, and splitting tensile strength tests were conducted on mixtures of sandy soil with different RHAs and lime. The results showed that the optimal reactivity of the RHA is reached for a range of controlled temperature of 650–800°C, providing a significant increase on the strength and stiffness of mixtures.Keywords: road materialsoil stabilisationrice husk ashburning temperature\vskip-1pc AcknowledgementsThe authors are grateful to the CAPES of the Brazilian Ministry of Education, to the Postgraduation Program in Civil Engineering of the Federal University of Rio Grande do Sul (Brazil) and the Geotechnical Department of University of the Republic of Uruguay for having funded and supported the research. Also, we thank Arrozur S.A. of Uruguay for providing the ash.