Effect of the Particle Size on TDA Shear Strength Parameters in Triaxial Tests

Abstract

Tire recycling and reuse in North America and worldwide have increased considerably, intending to reduce the harmful effects of scrap tires on the environment. Accordingly, the use of tire derived aggregates (TDA) as backfill material in civil engineering applications is on the rise at an unprecedented rate. However, to use TDA in the construction industry, its strength and stiffness parameters properties must be evaluated. One key factor that is known to influence the strength and stiffness of backfill material is the particle size of the used material. Hence, in this paper, a series of large-scale triaxial tests on five TDA samples with different maximum particle size, Dmax, of 19.05, 25.4, 38.1, 50.8 and 76.2 mm were conducted to investigate the effect of the particle size on the obtained results. The tests were done under consolidated drained conditions using three confining pressures of 50, 100, and 200 kPa. The results showed that the shear strength of TDA increase by increasing the maximum particle size while the cohesion did not show a specific trend. Moreover, the samples exhibited an increase in the secant elastic modulus by increasing the particle size.

Evaluation of the Shear Strength Behavior of TDA Mixed with Fine and Coarse Aggregates for Backfilling around Buried Structures

“…They concluded that sand-tire shred mixtures can be used as a lightweight material beneath conventional soils, and can exhibit a high resilient modulus due to confinement. Masad et al [37] also observed a strain-hardening behavior in pure tire chips similar to the observations of [33,34]. Lee et al [9] performed a series of large-scale triaxial compression tests to study the shear strength behavior of tire chips mixed with sand.…”

“…These researchers also noted that the effect on the cohesion intercept was negligible due the low confining pressures, ranging from 34.5 to 55 kPa. El Naggar and Zahran [33] carried out a series of large-scale triaxial compression tests of large size TDA particles at confining pressures ranging from 50 to 200 kPa to investigate the effect of the particle size on the TDA shear strength parameters. Whereas El Naggar et al [34] conducted consolidated drained triaxial tests on TDA with large particles using the same large-scale triaxial apparatus of [33] to develop an empirical hyperbolic material for TDA.…”

“…El Naggar and Zahran [33] carried out a series of large-scale triaxial compression tests of large size TDA particles at confining pressures ranging from 50 to 200 kPa to investigate the effect of the particle size on the TDA shear strength parameters. Whereas El Naggar et al [34] conducted consolidated drained triaxial tests on TDA with large particles using the same large-scale triaxial apparatus of [33] to develop an empirical hyperbolic material for TDA. El Naggar and Zahran [33] and El Naggar et al [34] reported internal friction angles ranging from 21.3 • to 25.6 • and cohesion intercepts from 28 to 32 kPa for different particle sizes when the failure was assumed to occur at 15% as per the ASTM standards as no peak was observed.…”

“…Whereas El Naggar et al [34] conducted consolidated drained triaxial tests on TDA with large particles using the same large-scale triaxial apparatus of [33] to develop an empirical hyperbolic material for TDA. El Naggar and Zahran [33] and El Naggar et al [34] reported internal friction angles ranging from 21.3 • to 25.6 • and cohesion intercepts from 28 to 32 kPa for different particle sizes when the failure was assumed to occur at 15% as per the ASTM standards as no peak was observed. Ashari et al [35] carried out a series of large-scale triaxial compression tests of sand-TDA mixtures at confining pressures ranging from 50 to 200 kPa.…”

Dynamic Properties of Granulated Rubber Using Different Laboratory Tests

“…It was concluded that the TDA backfill resulted in significantly less acceleration amplification at the backfill surface. Thus, the geotechnical properties of TDA have been extensively investigated recently to accurately predict its behavior under dynamic and static loads [13][14][15][16][17][18][19][20][21].…”