Experimental Studies on Controlled Low Strength Materials Using Black Cotton Soils and Comparison of Results with Taguchi Model

Abstract

In developing countries like India, due to fast urbanization and rapid development of infrastructure resulted in the use of soft and weak soils around for various Civil Engineering applications. The mechanical behavior of such nature of the soil has to be improved by employing stabilization and reinforcement techniques to make it reliable for construction activities. The black cotton soil is one of the major issues in India. BC soils when exposed to variation in moisture content they undergo high swelling and shrinkage making it more complicated for engineering point of view. The present study investigates the feasibility of controlled low strength material for stabilizing BC soils. The ACI-229R report describes controlled low-strength material (CLSM) as a cementitious material having compressive strength less than 8.3 Mpa (28 days). For the present study, a new greener CLSM comprising Class F fly ash, Cement, Common effluent treatment plant (CETP) Sludge, and Water was developed. The flowability and unconfined compressive strength test was carried out. It was observed from the experimental result that the maximum flowability was 19.8 cm for GF6 and maximum UCS value 0.259 MPa for GF7 mix. After finding the optimum mix, experimental work was carried out by mixing controlled low strength material with black cotton in different proportions. The CBR test was conducted to assess the strength gain of BC soil with different proportions of controlled low strength material and it was observed that there was a reduction in overall flexible pavement thickness of 11% by Controlled low strength material as subgrade stabilization In addition to that, Prediction model was generated using Taguchi’s method of design to avoid the conventional trial and error process. The results indicate that there was an increase in the nconfined compressive strength by increasing the (B/W) ratio.