Analysis of Geo-Concrete Composite for Use as a Pavement Base Course for Low-Traffic Roads

The present study concerns the improvement of the bearing capacity of a reddish clay lateritic gravel (GLAR) by adding a quantity of crushed granite 0/31.5 in order to use the mixture as a road base course. Geotechnical tests were carried out on natural GLAR, and Geo-concrete composite based on GLAR improved with 0/31.5 mm crushed granite stone at three mass ratios (20wt%, 30wt% and 40wt%). The results show a reduction in the Plasticity Index from 18.7% for the natural lateritic material, to 12.2%, 11.0% and 7.3% respectively at the 20wt%, 30wt% and 40wt% crushed granite amendment mass rates, representing a reduction from 34.76% to 60.96%. Analysis of the geo-concrete composite’s compactness showed that the dry density of the new composite increased by 2.81%, 4.75% and 17.36% with the introduction of Crushed granite 0/31.5 in the GLAR. Moreover, the 95% CBR bearing capacity of OPM has been improved by 2.94%, 5.88% and 27.94% respectively at 20wt%, 30wt% and 40wt% addition of crushed granite material. These results are in line with CEBTP 2014 specifications and indicate that these lateritic gravels reinforced with 0/31.5 mm crushed granite at rates of at least 20% can be used in road construction for the base course. Optimum mechanical stabilization or litho- stabilization is achieved with a 30% incorporation of crushed granite material in GLAR.