Evaluation of the stiffness modulus of a 0/14 bituminous concrete as a function of temperature

In Côte d’Ivoire, the development of the road network represents a major challenge for the national economy, with more than 80% of interurban transport carried out by road. However, bituminous pavements are subjected to mechanical and climatic stresses that accelerate their degradation. Among the factors influencing their durability, temperature plays a decisive role in the mechanical properties of asphalt mixtures, particularly the stiffness modulus. This study addresses this issue by evaluating the evolution of the stiffness modulus of a 0/14 bituminous concrete as a function of temperature.

The study was conducted at the Laboratory of Building and Public Works (LBTP) using aggregates from massive rocks and a 60/70 grade bitumen. Experimental methods included aggregate characterization tests (particle size distribution, sand equivalent, Los Angeles, Micro-Deval), bitumen tests (penetration, softening point), as well as mechanical tests (Marshall, Duriez, rutting, stiffness modulus according to NF EN 12697-26).

The results show that the stiffness modulus decreases significantly with increasing temperature: above 5000 MPa at 10°C, it drops to less than 1000 MPa at 40°C. This variation reflects a loss of rigidity and mechanical performance, making the asphalt more vulnerable to deformation. These findings highlight the need to adapt asphalt formulations to local climatic conditions to ensure pavement durability.