Development of High Strength Geopolymer Concrete using Nano Silica

Cement production became responsible of polluting the atmosphere by the emission of greenhouse gases. This issue motivate the researchers to work hard to develop a new cementitious materials used in concrete having much lower foot print in environmental pollution. This paper presents the development of high strength geoploymer concrete using nano silica. Ground granulated blast furnace slag (GGBFS) is used as main cementitious material and silica fume (SF) is used as cement replacement by different ratios. The alkaline activator is used in different temperature and samples cured by different methods. Nano silica then added to the optimum geopolymer concrete sample by ratios 1, 2 and 3% of the total weight of cementitious materials. Samples tested for mechanical properties. The results showed that using hot activator and oven curing samples gives higher mechanical properties. Also using nano silica up to 2% increases the compressive strength up to 24% at age 28 days.