Effects of colloidal nano-silica incorporation on the durability and mechanical properties of Portland Limestone Cement (PLC) concrete

Portland limestone cement (PLC) concrete is considered more environmentally friendly than ordinary Portland cement (OPC) because it contains less clicker content; however, in many cases PLC cement compromises the durability and mechanical properties of concrete. In this study, colloidal nano-silica (CNS) was used to improve the durability and mechanical properties of PLC concrete. The effects of two types of water reducers (lignin and polycarboxylate) on PLC samples were also studied. The results indicate that CNS incorporation improved the durability and mechanical properties of PLC concrete. The compressive strength of CNS samples improved by nearly 15%, the flexural strength increased by 16% with polycarboxylate, and by 4% with lignin water reducers, and the electrical resistivity increased by 40% at 28 days.