Resilient Response of Mechanical Cement-Stabilized Laterite Gravel

Rapid economic growth is leading to ubiquitous expansion in highway projects around the world. Utilization of natural aggregate resources for the construction of flexible pavement has led to uncontrollable quarrying in the state of Kerala, India. The recent landslides in Kerala are the aftermath of extensive quarrying activities. Utilization of treated native soil in the subbase and base layers of flexible pavement can widely avert the danger associated with ecological imbalance due to quarrying. In this study, engineering properties of mechanical-cement-stabilized laterite gravel were investigated for their effective utilization as a subbase course material in flexible pavements. The effects of cement content and the curing period on the resilient modulus and permanent strain of laterite gravel-stone chips-cement (LSC) mixes were investigated. A mix of 70% laterite gravel +30% stone ships stabilized with 7% cement was obtained as the optimum mix. The optimum LSC mix with a 28-day curing period exhibited 55% higher resilient modulus and 78% lower permanent strain than the conventional granular subbase (GSB). On the basis of finite element analyses of flexible pavement, it was found that the pavement with optimum LSC mix in subbase exhibited a design life ratio of 1.13 and 1.29 with respect to that of pavement with conventional granular subbase corresponding to rutting and fatigue failure criteria.