Mechanical effects of rice husk ash in ultra-high performance concretes: A matrix study

Rice husk ash (RHA) has been observed to greatly improve both the mechanical and durability performance of conventional concrete mixtures, including increases in compressive strength while improving resistance to chloride ion transport and decreased permeability. This study explores the effects of using RHA as a mineral admixture in an ultra-high-performance concrete (UHPC) matrix, for which very high compressive strengths have already been achieved through dense particle packing and selection of materials. RHA is a promising material because of its widespread availability, its effectiveness as a pozzolanic material, and its potential for creating more environmentally sustainable building materials. Results of this study indicate that through the inclusion of RHA, the compressive strength of various mixtures at various water-binder ratios was improved and that RHA should be considered further for its use as a pozzolan in UHPC.