A study on cracking behavior of marine soil modified with ultrafine slag under cured and uncured conditions
Authors :- R Wanare, P Jayanthi, KKR Iyer
Publication :- Materials Today: Proceedings, 2022
Desiccation cracking leads to alteration of the soil properties, as it creates the pathways for water ingress into subsoil medium. Researchers have reported the effects of cracking on soil such as, higher settlement, compressibility, reduction in stability and bearing capacity, and quality degradation of landfill liners. Although previous studies have focused on understanding the cracking behavior of soils and its mitigation, such studies for marine soil are rare. Therefore, keeping in view the challenges faced by geotechnical engineers for construction on marine soil, this paper presents an experimental study, on the drying behavior of marine soil, with the application of commercially available ultrafine slag (Alccofine® 1203) as a sustainable material, to minimize its cracking potential. Additionally, secondary admixture (activator) has been utilized to improve the efficacy of stabilization process. The study is done for both uncured and 7 days cured conditions, with proportion of ultrafine slag varying from 2.5% to 40%. Parameters such as, variation in water content, and crack and shrinkage intensity factor (CSIF), have been studied for both unstabilized and stabilized soils. It is observed that during drying, the CSIF values for stabilized soil reduces upto 38%, for cured conditions, and upto 57% for uncured conditions. Further, ultrafine slag less than 10% is not effective in reducing the CSIF values, and stabilized soils with activators exhibit better efficacy in reducing CSIF values. Moreover, uncured specimen exhibit better performance as compared to cured specimen for both unstabilized and stabilized marine soil, suggesting the importance of initial pozzolanic reactions in development of tensile strength in soil (uncured specimen), that reduces the susceptibility of soil to cracking. The study suggests potential of ultrafine slag as a sustainable material for controlling the cracking characteristics for marine soils and for stabilization of dredged material.