Comparative Study between the Technique of Treating Lateritic Gravelly Soil Improved with Crushed Granite (Litho Stabilization) and the Technique of Treating Soil with Cement: The Case of the Section of the Saaba Road Linking the Bypass Road in the City of Ouagadougou in Burkina Faso
Bernard GOUBA *
Department of Civil Engineering, University Center of Kaya, Burkina Faso and Laboratory of Renewable Thermal Energies (L.E.T.RE.), Joseph KI ZERBO University, Burkina Faso.
Boukari Sawadogo
Civil Engineering Department, University of Technology and Management, Ouagadougou, Burkina Faso.
*Author to whom correspondence should be addressed.
Abstract
Burkina Faso is a developing country, with most of the transport being done by land. Like all Sahelian countries, Burkina Faso uses lateral gravel as a foundation layer and 60 to 70% of the base layers.
In view of the current high traffic, its use in road construction in its natural state sometimes has low load-bearing capacity causing the rapid degradation of the foundations, which led Burkina Faso to adopt a technique of improving lateritic gravels with cement (cement soil) and crushed granite (litho-stabilization). In our study, we use a sample of recycled lateritic gravelly material taken from borrowed heaps and enhanced with crushed granite and cement at different percentages to achieve the bearing capacity meeting the technical specifications of the CCPT.
After improvement with crushed granite at 20%, 25%, and 30%, we obtained the following result at 25% CBR index 124 at 98% and 82 at 95% and after formulation study, the cement improvement made with 1%, 1.5%, 2% gave a satisfactory result at 1.5% with a CBR of 90 to 95% and 138 to 98%. Cement improvement offers better technical results than litho-stabilization. However, from an economic point of view, cement soil is less expensive than litho-stabilization because of the low percentage of cement addition (1.5%).
Keywords: Lateritic gravelly, litho-stabilization, cement floor, improvement, index, carbon loan