Compressive strength, modulus of elasticity, and water permeability of inorganic polymer concrete

Inorganic polymer concretes (IPCs) were produced from rice husk–bark ash (RHBA) combined with fly ash (FA) as a cementitious raw material. Six different mixtures were used to study the properties of IPC. Since RHBA is rich in silica material, varying the ratio of FA to RHBA results in differing SiO2/Al2O3 ratios. To keep the SiO2/Al2O3 ratio constant, the ratio of FA to RHBA was fixed at 80:20 by weight. High concentration sodium hydroxide solution and sodium silicate solution were used as a liquid component of the concrete mixture. The mixing and curing of these inorganic polymer concretes were performed under ambient conditions. Compressive strength, modulus of elasticity, and water permeability of the IPCs were investigated at specified intervals up to 90 days. The results showed that the compressive strength, modulus of elasticity, and water permeability of IPCs depend on the mix proportions, especially the solution to ash (S/A) ratio and the paste to aggregate (P/Agg) ratio. Moreover, the results showed that the water permeability and the elastic modulus of IPCs were significantly related to their compressive strength.