Experimental study on the use of RoadCem blended with by-product cementitious materials for stabilisation of clay soils

This work presents an experimental study on the physical, mechanical and microstructural characteristics of two clay soils treated with by-product materials (GGBS and PFA) blended with a nano technology-based additive called RC (RC). The soils were initially treated with 8% of cement in the first phase of mixing, and in the other phases of mixing, the cement content was reduced by 50%, 60% and 70% and substituted with GGBS or different combinations of GGBS and 1%RC or PFA and 1%RC. Further, the paper discusses the shear strength, stabilisation mechanism, microstructural characteristics, and swell of the treated soils based on results of series of strength, scanning electron microscope and swell test. The results show that the inclusion of 1%RC increases undrained shear strength and reduces swell of the treated soils due to encapsulation effects associated with the formation of the crystalline reaction product in the hydration process and the resulting modification of cementitious product to bind very heavy clays together. The soil treated with 1%RC combined with 4%Cem and 3%GGBS, produces the best performance in terms of undrained shear strength and microstructural characteristics and the stabilisation mechanism of cement, RC and GGBS shows that it is due to interlocking of particles and wrapping effect.