Effect of Nano-Clay on Alkali Activated Water-Cooled Slag Geopolymer

Ground granulated blast furnace slag is a finely ground, rapidly chilled aluminosilicate melt material that is separated from molten iron in the blast furnace as a by-product. Rapid cooling results in an amorphous or a glassy phase known as GGBFS or water-cooled slag (WCS). Alkaline activation of latent hydraulic WCS by 6% sodium hydroxide was studied. Nano clay is an ultrafine material that produced from firing kaolin material up to 800ºC for 2hrs with a heating rate of 5ºC/min; this can modify mechanical, microstructural and thermal properties of geopolymer products and added to the geopolymer mix in the ratio of 0 up to 7% of the dry weight. Curing was performed under 100% relative humidity and at a temperature of 38ºC. Gelenium Ace super-plasticizer was added in the ratio of 4% from the dry weight to ensure good dispersing of the used nano clay. Results showed that increasing the percentage of nano clay up to 1% results in an enhancement in the mechanical properties as compared with control mix up to 90 days, while higher ratio leads to matrix dilution and so negatively affect mechanical characteristics of the resulting products. The study of thermal properties is taken place for the different ratios by experimental and mathematical evaluation. Study shown that the thermal properties as well as thermal insulation properties improved with the increased ratio of nano clay in ratio 1-1.5%.