Comparison Of Mechanical Properties Of Clayey Soil Stabilized With GGBS And Flyash Using Geopolymerisation Process

There has always been a need to stabilize the soil to make it stable, induce strength, and be durable. Physical and chemical methods are followed for this purpose, followed by mechanical means to stabilize the soil. Much research in this regard has been done in the past, but the results were never too satisfactory as it was not possible to entirely alter/convert the soil crystal structure, or in other words, to recrystallize the silicates aluminates and lime present in the soil. Geopolymerisation, a comparatively new technology, comes as an aid towards this problem. Recent research on this process has proven beneficial for stabilization, but most studies have stated their results are based on a change in one or two parameters at a time. The present study has examined at least two parameters in detail that significantly influence the geopolymerisation of soil. These are alkali concentration and binder composition. For a given sodium silicate to sodium hydroxide ratio, i.e., 2.5, compacted soil samples have been prepared at 10% alkali solution by weight of dry soil mass and tested after 7 & 28 days. Water has been used beyond the alkali solution to achieve a maximum dry density of soil mass. It has been found that GGBS is much beneficial in the presence of flyash as their combined synergic effect improves both the gradation and polymerization potential in the soil mixture. About 40% soil substitution is appreciated as more substitution will encourage more alkali requirements which will not be cost-effective.