Development of Granular Sub Base Using Marginal Materials

Abstract

Granular Sub Base course is the sub base layer constructed in the flexible pavements. It is used as drainage layer to drain the precipitated water and the capillary rise water from sub grade to side drains. For developing GSB, locally available lateritic soil procured from the field is used. Since the soil is not meeting the specifications of MORTH for sub base, its properties have to be improved by blending with marginal materials like sand or quarry dust which are abundantly available in this region. Crushed granite aggregates have been used to meet gradation requirements for granular sub base course. Proportioning to get the required gradation of GSB has been tried in the laboratory to satisfy the GSB requirements and permeability tests were also conducted on thus prepared GSB's. Cost analysis has also been carried out to know the savings in terms of conventional materials.