DEVELOPMENT OF A NEW PRODUCT FOR THE OPTIMIZATION OF THE GEOTECHNIC CHARACTERISTICS OF THE BASE COURSE IN THE ROADS CONSTRUCTION IN SOUDANOSAHALIAN AREA: CASE STUDY OF THE MAROUA AGGLOMERATION

Road infrastructure is expensive for developing countries. Indeed, on the one hand the outdated implementation techniques, and the unavailability of standards materials such as crushed gravels in some project areas, attest to and accentuate this difficulty. The northern part of Cameroon is part of the Sudano-Sahelian area of the African continent. Which is characterized by the scarcity and remoteness of rocky deposits as well as the delicacy of extraction conditions, illustrative of areas where road construction generates the most prohibitive expenditures. The work carried out, which is based on the mixture techniques commonly used in soil concretes, aims to implement locally in abundance available materials, by associating them a minimum fraction of hydraulic binders, in order to obtain a new constituent for the base course of road construction, according to the universal standards. After a comprehensive documentary compilation and experimental approach in the laboratory with samples taken in the extreme north of Cameroon, the results are convincing: the constituent of the mixture comprising 70% of sand, 25% of soil and 5% of hydraulic binder, meets the eligibility criteria prescribed in the implementation of the base course in road construction, in particular the bearing index or stability (CBR) and the hardness of skeleton's (Rc, Rc ‘) product. This mixture would be recommended for road construction in the Sudano-Sahelian areas, alternating with crushed gravels which is scarce. Its implementation according to the prescribed optimal conditions, generally reduce considerably the expenses for an efficient development of road network in the Sudano-Sahelian area, and precisely in the north of Cameroon