Effect of olive waste ash on the properties of high‐strength geopolymer concrete

Abstract This study examines the effect of incorporating olive waste ash (OWA) into high‐strength geopolymer concrete (HSGC) by partially replacing fly ash (FA) and/or granulated blast furnace slag (GBFS) in the presence of rice husk ash (RHA). A total of 18 different mixtures were prepared and divided into three groups: (1) Utilizing OWA as a partial replacement for FA at a weight ratio of 10%–50%. (2) Incorporating OWA as a partial substitute for GBFS, with a weight ratio of 10%–50%. (3) Incorporate OWA as a partial substitute for FA and GBFS, with a recommended weight ratio of 10%–50%. The slump flow test was used to analyze the fresh properties of the HSGC. The hardening properties were examined by measuring the compressive strength, tensile strength, flexural strength, and modulus of elasticity. Furthermore, an analysis was conducted on the water absorbency, sulfate attack, and chloride penetration depth. A scanning electron microscope was used for the microstructural analysis. The inclusion of OWA in HSGC mixtures resulted in a significant enhancement of the compressive strength. Specifically, adding 20% OWA to FA increased the compressive strength by 8.9% at 28 days. Similarly, 30% OWA for GGBS and 30% OWA for GGBS + FA led to compressive strength improvements of 20% and 17.8%, respectively. OWA application resulted in an enhanced microstructure density of the HSGC samples. The ideal substitution ratio varied between 20% and 30% based on weight.