Feasibility Study of Retaining Walls Backfilled with Sand-Tire Chip Mixtures

Abstract

Proper management of waste tires is a major problem in many regions of the world. Scrapped tires in different forms are being used in various civil engineering applications. This paper presents the feasibility study on the use of recycled tire chips mixed with sand as lightweight backfill material for retaining wall applications. Properties of sand and sand-tire chip (STC) mixtures and model tests conducted on retaining wall models with these materials are briefly summarized. Investigations on use of different STC mixtures (different proportions) indicated that STC30 mixture (30% of tire chips by weight) is most efficient in improving wall behavior in terms of displacements and pressures. To evaluate the financial benefits in the construction of cantilever retaining wall for three different sizes (3, 6, and 9 m height) with STC0 (sand alone) and STC30 mixture as the backfill material, wall designs including the structural designs and cost analyses are presented. Based on the feasibility studies, it is indicated that STC30 mixtures have lower bending moment and shear force on stem, heel, and toe. Thus, the STC30 shows the better sustainable backfill material for retaining wall structures providing a financial benefit of about 30%.