Study on the Effect of Alkali Activated Ground Granulated Blast Furnace Slag on Cracking and Shrinkage
Authors :- R Wanare, KKR Iyer
Publication :- Proceedings of 9IYGEC 2023, Volume 1, Lecture Notes in Civil Engineering, Springer, 2024
Marine soils are prone to cracking during drying and can pose great challenges due to loss in bearing capacity, deterioration, and failure of slopes, etc. However, crack reduction/mitigation of marine soils has not gained much attention of researchers. The present study focuses on understanding the effect of ground granulated blast furnace slag (GGBS) with secondary admixtures/alkali activation, on the cracking and shrinkage characteristics of marine soil. The cracking/shrinkage characteristics of marine soil have been evaluated during drying at 27 ± 2 °C and 50 ± 5% relative humidity, and images have been taken at regular stages of drying. Crack and shrinkage intensity factor (CSIF)/shrinkage intensity factor (SIF) have been utilized to quantify the cracking and shrinkage/shrinkage characteristics, respectively. GGBS (5–15%), lime (0–3%), and alkaline materials (0–3%) such as KOH, NaOH, Na2CO3, and Na2SiO3 have been utilized as admixtures in the present study. It has been observed that marine soil with GGBS yields some reduction in CSIF but does not result in crack mitigation. Further, the addition of GGBS and lime in marine soil results in a substantial reduction in CSIF, but results in peripheral/internal cracking and shrinkage for most specimens. Furthermore, the addition of lime and alkaline materials (viz., KOH, Na2SiO3, etc.) with GGBS in marine soil results in complete crack mitigation. The study results are quite encouraging in the context of stabilization of dredged soil in marine environment and improving the stability of marine shores and slopes.