Durability study on ambient cured geopolymer concrete made with various molarities of NaOH

Geopolymer concrete is an innovative variation of the conventional construction material that reduces the environmental impact of producing Ordinary Portland Cement (OPC) while simultaneously improving the efficient use of industrial by-products. By altering the molarities of sodium hydroxide to 4M, 6M, 8M, 10M, and 12M, five combinations of geopolymer concrete were prepared for this study. After 28 days of curing at room temperature, the strength properties, viz., the compressive strength (DT and NDT), the splitting tensile strength, and the flexural strength were evaluated. Additionally, the durability properties such as the initial water absorption, saturated water absorption, sorptivity, average effective porosity, abrasion resistance, and chemical attack resistance were studied as well. All the findings of the geopolymer concrete were compared to those of the M35 grade OPC concrete. The experimental test results showed that, with the exception of GPC-4M, the other Geopolymer concrete mixtures met the target strength requirements of the M35 grade concrete. The findings revealed that the GPC-8M concrete specimens performed the best in terms of strength and durability. Consequently, widespread use of geopolymer concrete, which is prepared with fly ash (FA) and ground granulated blast-furnace slag and cured in ambient air, is recommended instead of OPC concrete.