CONTRIBUTION TO THE IMPROVEMENT OF BITUMINOUS ENROBES: APPLICATION TO THE DEVELOPMENT WORKS OF THE YAOUNDE-DOUALA MOTORWAY IN CAMEROON

The frequent closure of roads for the sake of maintenance and refurbishment is an increasing problem for the road administrators and users, because of induced high costs, restrictions and influence they impose, traffic jam, and the many other disruptions such interventions have on traffic. In these circumstances, carriageways with long life span, with adapted tar, have much to offer, especially if they can exhibit optimum performances without requiring major repairs for over 30 years. On high traffic roads, research has shown that binders with elevated modules are a reliable and credible alternative to render their life span more sustainable and durable. In this context, the advantages presented by the absence of important repairs and refurbishing can be enough to justify the initial high costs of these advanced carriageway coatings. Studies on the different binders to be used were done, which have permitted in accordance with the performance of the layers, the required tests and the different study levels. Also, this has permitted us to analyze the obtained results and conclude that due to the expected needs, the LA and MDE tests, the PSV tests are the criteria that determine the selection of aggregates; The complexes modular methods, fatigue resistance (level IV), is to be necessary for the forecasting of the mechanical behavior of bituminous materials.