Strength Characteristics of Clay-Rubber Waste Mixtures in UU Triaxial Tests

Abstract

This paper presents results of undrained and unconsolidated (UU) triaxial tests related to the influence of tire waste addition on strength characteristics of red clay from Patoka in Southern Poland. Angle of internal friction and cohesion values were estimated for 30 specimens prepared from pure red clay (RC), its mixtures with two different fractions of shredded rubber in 5%, 10%, and 25% mass proportions as well as for pure powder (P) and granulate (G). It has been observed that the addition of granulate contributes more to the increase in the angle of friction than the addition of powder (uu = +1% (G-5) / +16% (G-10) / +31% (G-25), uu = +1% (P-5) / +10% (P-10) / +19% (P-25)). On the other hand, rubber additions reduce cohesion in mixtures, and the effect is enhanced with increases in their grain size and percentage composition (cuu = −31% (G-5) / −63% (G-10) / −87% (G-25), cuu = −67% (P-5) / −58% (P-10) / −58% (P-25)). It has been noticed that a change of parameters uu and cuu causes a decline of shear stresses at increasing granulate content. There is an inverse relationship for powder. At the same time, it has been shown that the failure strain, hence a change in red clay-rubber (RCR) mixtures plasticity, is related to the level of confining stress 3 and the type of rubber waste. Results of tests and their comparison with results of other researchers show that each time it is necessary to experimentally verify a given soil with specific rubber waste.

Advances in Properties of Rubber Reinforced Soil

“…It is found that the mixing of granular or fragmented rubber into cohesive soil can reduce the mass of soil and improve the shear strength of soil mass [89,90]. Because the density of rubber particles is smaller than that of clay particles, the density of the mixture decreases [70]. Compared with cohesive plain soil, the dry bulk density and optimum water content of clay mixed with rubber particles are reduced, so the reinforced soil has lower specific gravity, which can be used as light filler [91,92].…”

“…e addition of rubber particles contributes more to the increase of friction angle than powder. [70] Advances in Civil Engineering clay, which can also improve the permeability coefficient of soil and improve the drainage characteristics of clay [93]. Some studies have shown that rubber can reduce the dynamic shear modulus of clay and increase the damping ratio, which indicates that rubber can effectively improve the seismic isolation and shock absorption performance of clay [32,94].…”

Application of Clay–rubber Mixtures for the Transportation Geotechnics—the Numerical Analysis

“…Rubber waste from car tires can be used for this purpose, according to the rule "end-of-life tires" (ELT). Each such new application requires research [18,24,50]. Among the tests performed, direct shear tests [6,28,45], unconfined compression tests or triaxial tests [1,18,46] dominate.…”

Stress-dilatancy relationship of sand-rubber mixtures

“…Shreds and larger chips often increase 1260 (2022) 012003 IOP Publishing doi:10.1088/1757-899X/1260/1/012003 2 peak shear strength but smaller chips, crumbs have no effect on strength or negative effect [10,11]. The rubber fibres inclusion into clays gives benefits at low stress levels and no benefits at high stress levels [10,12].…”