 This study examined the potential of rice husk ash, RHA, a type of agricultural waste, as a replacement for Portland cement in high-performance concrete. Results showed that the addition of RHA resulted in improved mechanical properties, including compressive and flexural strengths, and chloride ion penetration resistance. Furthermore, the use of RHA was found to be comparable to the use of silica fume, SF, another commonly used additive for high-performance concrete. Therefore, this study suggests that RHA could be a viable alternative to SF in high-performance concrete applications. This article was authored by Andres Salas Montoya, Chu Wuchang, and Ji Hyun Kim.