A comparative study between strength and durability of bentonite and natural gum stabilised sand

Abstract

ABSTRACT The loss in strength of engineered geo-materials due to their exposure to adverse environmental conditions is a major problem and is investigated in terms of durability. In the present study, geo-materials are developed using the sand obtained from river Yamuna and is stabilised with bentonite or two different types of biopolymer (Guar gum and Xanthan gum) separately. The maximum percentage of bentonite is fixed as 25% by dry weight, whereas the biopolymer (0.5%, 1.0%, 1.5%, and 2.0%) is used by making its solution with distilled water. A continuous increase in the unconfined compressive strength is observed in the bentonite stabilised sand whereas an optimum percentage of both the biopolymers is observed as 1.5%. The penetration resistance is presented in term of CBR value and resilient modulus is calculated using the same. Although, the bentonite and Guar gum stabilised sand demonstrate higher strength compared to Xanthan gum stabilised sand; however, the former is not found stable when submerged in water. More than 50% loss in strength for sand stabilised with 1.5% and 2.0% Xanthan gum is observed. Further, the stability of the biopolymer stabilised sand in submerged condition is discussed with the help of SEM images.