Fatigue behavior of Lateritic soil stabilized with enzyme and effectiveness of flexible pavement with stabilized soil as sub-base

Abstract

The Lateritic soil is abundantly available in coastal Karnataka (India). To improve its properties the soil has to be stabilized either mechanically or chemically. Soil stabilization using enzyme is one of the methods developed recently. Various experimental investigations have shown that Atterberg's limit values are improved favorably and there is increase in CBR values. The unconfined compressive strength increases with the increase in curing period when treated with enzyme. These improvements mainly depend on type of soil and enzyme used. In recent past many enzymes have come to the market which can be used as a stabilizing agent. In the present investigation commercially available enzyme is used for stabilization of lateritic soil and improvement in Unconfined Compressive Strength (UCS) has been investigated. It has been observed that the enzyme treated soil shows significant improvement in terms of UCS with longer curing period. Considering this, fatigue behavior of enzyme stabilized soil samples has been studied to find relationship between UCS, fatigue life, enzyme dosage and curing period and correlation between them has been established through multiple regression analysis. Considerable amount of improvement is observed in its fatigue behavior when subjected to repeated loading. This enzyme stabilized soil is used soil as sub base layer in the design of flexible pavements. Using the results of laboratory tests on enzyme treated lateritic soil, the thickness of sub base required has been calculated with the help of "KENPAVE" software. The thickness obtained is compared with the thickness suggested by Indian Road Congress (IRC) for defined sub grade strength (CBR value). Cost comparison has been made considering conventional method of design. � 2011, Advanced Engineering Solutions.