Enhanced sand strength through low-density polyethylene reinforcement

Abstract

The current study examined the impact of incorporating low-density polyethylene (LDPE) on the behavior of sand through consolidated-drained triaxial tests. The tests varied parameters such as percentage addition and inter-particle void ratio. Results showed that the peak strength of LDPE-mixed sand increased by roughly 40% for 1.5% to 2.0% LDPE content compared to unreinforced specimens. However, peak strength decreased with further increases in LDPE content beyond 2.0%. Thus, LDPE content of 1.5% to 2.0% was identified as the optimal mass percentage for increasing sand strength. The shear stiffness of the LDPE mixed sand also decreased by 25–35% compared to unreinforced samples. The study attributed strength variation and stiffness reduction of sand mixed with LDPE to friction characteristics between sand particle-to-sand particle, sand particles-to-LDPE, and LDPE-to-LDPE, and microscopic observations of the specimens. Although low-friction LDPE reduced initial stiffness, peak strength increased due to the pullout resistance of LDPE sheets across potential shear bands. However, excessive LDPE addition caused pronounced overlapping of LDPE sheets, leading to a decrease in frictional properties and a reduction in strength.