An Investigation into the Compressibility and Lateral Stresses of Sand–Carpet Mixtures Using a Large Oedometer Apparatus

Abstract

In this paper, the deformation properties of sand, reinforced with carpet waste, are investigated by carrying out a set of large-scale oedometer tests under different overburden pressures. The oedometer apparatus employed in this study has been equipped with vertical and lateral pressure cells, which allow the value of the soil’s coefficient of lateral pressure at rest, to be determined as well as its compressibility. Carpet waste was added to sand at weight percentages of 0, 5, 10 and 15%. Results were indicative of a reduction in the coefficient of lateral pressure at rest, K0 with the increase in carpet content of the mixtures. The reduction in the value of K0 amounted to 10% at a carpet content of 15%. The compressibility properties of the mixtures were evaluated as well, by recording one-dimensional displacement in the samples. Results demonstrated an increase in the coefficient of volume change with the increase in carpet content, particularly for lower levels of overburden pressure. Predictive models were developed based on the multi-linear regression (MLR) procedure to predict the coefficient of lateral pressure at rest and coefficient of volume change for the sand–carpet mixtures normalized to the values of sand.