Replacing the Aggregate by Rice Husk Ash in Roller Compacted Concrete for Composite Pavements

World rice production reaches 662 million tons per year. The husks represent 20% of this amount and when burned, 20% of this byproduct is transformed into rice husk ash (RHA). In general, there is not an environmental management policy concerning this residue. Roller compacted concrete (RCC) is a material which permits the incorporation of industry byproducts such as RHA. This article presents laboratory results of mixtures of RCC with the addition of RHA in its application in composite pavements. Natural RHA was utilized in order to partially substitute the mineral aggregate in diverse proportions within the RCC dosage. The properties evaluated were compressive strength, flexural strength, and modulus of elasticity. The results demonstrated that a significant improvement in the properties studied may be achieved with the addition of RHA in RCC. This study also indicates that the addition of RHA in mixtures of RCC may lead to reduced consumption of cements and lesser demand for aggregate minerals. As such, the use of this material in highway construction in rice-producing regions would contribute to environmental management of this residue.