Avlamè Lateritic Aggregate Stabilised with Cement, Technical Characteristics and Possibilities of Use in Road Construction

Abstract

Benin, like many African countries south of the Sahara, has lateritic gravel that does not meet the technical specifications required for use in road bases. In fact, recourse to quarries with lower quality materials, such as the lateritic quarry of Avlamè, is felt with the exhaustion of good quality materials. Faced with this situation, it is important to enhance the value of the Avlamè lateritic aggregate by the cement stabilisation technique with a view to its use in the base layer of pavements in Benin. Thus, an experimental study on the lateritic aggregate of Avlamè with different cement dosages was carried out according to the standards in road construction. This characterization allowed to highlight the mechanical properties of the lateritic aggregate treated with cement at different dosages. The most important results are obtained with the dosage of 4.50% cement. These are dry density 2.34 t/m3 , plasticity index 8.98%, yield strength 27.33%, CBR 221.33%, direct tensile strength 0.28 MPa, compressive strength 4.30 MPa and secant modulus 1531.71 MPa all obtained at 95% of the modified Proctor optimum. Using the strength adjustment curves, the 6.50% cement content gives a direct tensile strength of 0.51 MPa against a compressive strength of 15.10 MPa and a secant modulus of 2163.36 MPa. These results show that Avlamè lateritic aggregate can be used as a base course for semi-rigid pavements when it is stabilised at a cement content of at least 6.50% in accordance with the specifications of the CEBTP 1984 guide and revised in 2019