Experimental study on sustainable stabilization of marine soil with ultrafine slag and activator for controlling its cracking characteristics

Desiccation cracking results in deterioration of soil properties, accelerates infiltration of water in soil, increases settlement and reduces the strength of soil. Soil stabilization has been utilized for mitigation of cracking in soils. However, the effect of soil stabilization on cracking behaviour of marine soils, has not received much attention. In this regard, the present study evaluates the cracking and shrinkage behaviour of marine soil. Efforts have also been made to understand the effect of ultrafine slag as sustainable admixture with/without activators (lime/cement) on crack mitigation and shrinkage reduction for marine soil. It has been observed that at lower proportion of ultrafine slag (upto 10%), the effect of stabilization is negligible, probably due to inadequate nucleation sites for cementation. However, at higher proportion of ultrafine slag (20–40%), the reduction in crack and shrinkage intensity factor (CSIF) and shrinkage intensity factor (SIF) for restrained and unrestrained specimen has been noted as 12–38% and 17–49%, respectively. From the study, it has been further observed that stabilization of marine soil with ultrafine slag and activator is more effective in reducing the crack/shrinkage intensity, as compared to only ultrafine slag; wherein soil M1 with 19.5% ultrafine slag and 0.5%C has been noted to be the optimum combination in the study, exhibiting crack mitigation during drying for moderate (27 °C) and high temperature (45 °C) regimes. The study also presents the mechanism for understanding the cracking and shrinkage behaviour of unstabilized and stabilized marine soils. The study findings would be quite useful for stabilization of marine soils for shore protection applications, and for stabilization of dredged material for their reutilization in infrastructure applications.