Model Study on Cyclic Loading Responses of Flexible Pavement System Laid on Expansive Subgrade

Abstract

Flexible pavement system laid on the expansive soil subgrades show signs of continuous distress in the form of cracking, unevenness, rutting, etc., during its service period. Extensive laboratory, model, and field studies have been carried out by various researchers have shown promising results with the utilization of industrial by-products, i.e., quarry dust, rice husk ash, blast furnace slag, flyash, etc., for the stabilization of expansive subgrade. These materials offer two folded advantage of effective utilization and solution for their safe disposal. In this present work, an attempt has been made to study the efficacy of flyash in stabilizing the expansive soil subgrade. Laboratory experimentation was conducted for finding the optimum content of flyash required for treating the expansive soil. Model flexible pavement systems are prepared in circular tanks with different untreated and flyash treated subgrade layers. Tests are conducted to study their cyclic load responses. The experimental results show that model flexible pavement with 10% flyash treated subgrade is showing low heaving and low settlement to the applied cyclic loading. The coefficient of elastic uniform compression, representing variation of elastic rebound of the model pavements is assessed for model pavements.