Influence of Additives and Durability Cycles on the Resilient Modulus of Asphalt Stabilized Soil

Saad Issa Sarsam; Abeer Husain Mohsen

doi:10.3759/joge.v4i2.3688

Abstract

Asphalt stabilized subgrade soils usually show a nonlinear and time dependent response under traffic loading. The elastic property of asphalt stabilized soil is defined by the resilient modulus to represent the nonlinearity behavior with respect to stress level. The aim of this work is to study the impact of durability cycles and additives on the resilient modulus and plastic parameter of the asphalt stabilized soil. Additive materials such as lime and silica fumes of (0.5, 1.5, and 2) % by weight of dry soil have been added after determination of the optimum fluid content which was (15%), (6% cutback asphalt+9% water). Durability of asphalt stabilized soil in terms of (freezing-thawing) and (cooling-heating) cycle was investigated under repeated indirect tensile strength. It was observed that Resilient modulus increases by (100%) and (20%) when lime and silica fumes were added, respectively. The variation in the rate of resilient modulus among number of durability cycles was detected. Resilient modulus decreases by (57%, 65% and 68%) and by (4%, 12.5% and 59%) under (10, 20 and 30) cycles of (cooling and heating) for asphalt stabilizes soil mixed with 2% of lime and silica fumes, respectively, while it decreases by (75%, 80% and 83%) and by (73%, 76% and 83%) under (10, 20 and 30) cycles of (freezing-thawing) of asphalt stabilized soil mixed with (2%) of lime and silica fumes, respectively.Keywords: Aspha