Assessment of different agents for stabilisation of a clay soil

Abstract

The effects of different agents on stabilisation of a clay soil were investigated through a series of laboratory experiments. The selected agents were cement, Ground Granulated Blast Furnace Slag (GGBS), mixture of GGBS and MgO (Magnesia) (GGBS:MgO) and mixture of GGBS, MgO and cement (GGBS:MgO:Cement). Mixtures of GGBS:MgO and GGBS:MgO:Cement were prepared at ratios of 3:1 and 3.0:0.5:0.5 by weight respectively. 5%, 10% and 15% of these agents were mixed with soil samples. Atterberg limits and standard compaction tests were conducted on the mixtures. Also, unconfined compressive strength (UCS) tests were performed on compacted samples from the natural soil and the above mixtures at curing times of 7, 14 and 28 days. The results showed that all the used agents cause increase in the strength of the samples and the amount of increase is dependent on the percent of the agents and the curing time. It was revealed that the activation of GGBS with MgO and MgO:Cement is effective in increasing the strength in comparison with GGBS alone. Based on the scanning electron microscopy (SEM) results, it was found that the increase in strength of stabilised soil is resulted from bonding between soil particles and stabilizing agents.