Sugarcane bagasse and rice husk ash pozzolans: Cement strength and corrosion effects when using saltwater

The production of ordinary Portland cement (OPC) contributes to the release of harmful greenhouse gases. In an effort to reduce these emissions, this study explores biomass materials to evaluate their use as partial replacements for ordinary Portland cement. Rice husk and sugarcane bagasse are agricultural waste products and large amounts of these are currently landfilled, making them inexpensive and available. When combusted at high temperatures they form rice husk ash and sugarcane bagasse ash with pozzolanic characteristics. The high silicon dioxide levels in these products make them good options to use as partial replacement for OPC. Replacement with 20% rice husk ash or 10% sugarcane bagasse ash give similar compressive strength and corrosion resistance for hardened cement paste samples compared to control OPC samples, if appropriate amounts of plasticizer are used. Porosity as measured by water adsorption trended higher with increased water to cement ratio due to replacement of cement with pozzolan, since water to binder ratio remained constant at 0.45:1. This study used saltwater in the mix, to investigate the use of a resource that requires less energy use in ocean-bordering areas.