Mechanical Properties of Sand Enhanced by Combined Polymer Stabilizer and Natural Fibers

In this research, a soil reinforcement approach was explored by introducing a polyvinyl acetate polymer treatment along with sisal fiber material, considering two mean particle sizes (D = 0.63 and 2.00 mm). The sand specimens were mixed with varying sisal fiber contents (F = 0 to 0.8%) and polyvinyl acetate polymer contents (PVAc = 6%, 9%, and 12%). A series of unconfined compression tests were performed to evaluate the compressive strength of the tested materials. The experimental findings indicate a positive correlation between the concentration of polyvinyl acetate polymer and the unconfined compressive strength within the tested range. The shear strength and of the sand initially increases with rising sisal fiber contents and then decreases with further increments in sisal fiber, peaking at a maximum value when the fiber content reaches a threshold of 0.6%. The findings validate the significance of the strain energy parameter as a reliable indicator for elucidating and forecasting the mechanical characteristics of soil reinforcement. New correlations have been developed to predict variations in unconfined compressive strength and peak strain energy based on the studied parameters (F, PVAc, and D). The agreement between predicted and measured characteristics validates the effectiveness of these established relationships in accurately predicting UCS and strain energy factors.