Sand–Tire Chip Mixtures for Sustainable Geoengineering Applications

Abstract

The applications of scrap tire-derived recycled materials in civil engineering applications have been increasing largely because of their potential economic and environmental benefits. This paper first evaluates sand–tire chip (STC) mixture properties and then discusses about the application of STC mixtures in geoengineering applications through laboratory model studies. Locally available sand and tire chips of 20 mm long with 10 mm square cross section are adopted for preparing the STC mixtures. Tire chips are mixed with sand in various percentages, ranging from 10 to 70 % with an increment of 10 %. Index and mechanical properties of sand–tire chip mixtures are determined for different proportions. Based on large direct shear tests, it was found that internal friction angle values are increased with TC contents up to 30 %. The study indicates that the optimum percentage of tire chips of the selected size is in the range of 30–40 % by weight, which is the equivalent of 50–60 % by volume. Model tests on retaining wall models by using various STC mixtures ranging from 10 to 50 % were discussed. The paper concluded that the STC mixture at the optimum ratio results in lightweight material with 20 % less unit weight with better strength parameters and compressibility behavior, which can effectively be used for geoengineering applications.

Notations

TC(%):

Percentage of tire chips

W _tc :

Weight of tire chips, kg

W _s :

Weight of sand, kg

G _m(cal) :

Calculated specific gravity of mixture from density test

W _m :

Weight of sand–tire chip mixture, kg

W _tc :

Weight of tire chips, kg

G _s :

Specific gravity of sand

G _tc :

Specific gravity of tire chips

e _total :

Total void ratio

V _m :

Volume of mold

V _tire :

Volume of tire chips in the mixture in m³

V _sand :

Volume of sand in the mixture in m³