Characterization of Paving Blocks for Road Pavement: Case of the Urban High-Intensity Manpower Program in Senegal

A large network of paving blocks has been initiated in some districts of the region of Dakar (Senegal) within the framework of the Urban Program of High Intensity Manpower (PUHIMO). The purpose of this study is to explore the process of production of paving blocks to be used for roads and sidewalks. The study also seeks to investigate the materials used for the formulation of hydraulic concrete for the manufacturing of paving blocks that are H-shaped. The blocks made are 20 × 10 × 6 cm 3 of size. The originality of this paper is the complete substitution of crushed basaltic sand by the fines of alumina phosphate that are stored for a long time over large areas. These fines particles of phosphate are generated by the physical processing (crushing, transportation and screening) of the raw alumina phosphate material. This paper deals with how to make good paving blocks out of crushed basaltic sand on the one hand and on the other hand with how to substitute basaltic sand for fines of alumina phosphate as waste for their recycling. The finished products are tested, for their resistance to splitting rupture, for their abrasion and for their water content, to see their compliance with the European standard EN 1338, which defines, according to the results obtained, their use or not in road pavement and in sidewalks. The standard values must be below 23 mm for abrasion, 3.6 MPa for the tensile rupture strength and 6 % for the percentage of total water content. Average abrasion values of 20.71 and 22.67 mm, 5 and 3.46 MPa of splitting rupture strength, 5.26 and 7.73 % of average water content are obtained in paving blocks made respectively out of crushed basaltic sand and out of fines of alumina phosphate. These results obtained testify good physical and mechanical characteristics of the paving locks made out of fines of alumina phosphate compared to the standard, if tolerance values are taken into account.