Evaluation of Stabilized Weak Subgrade Material on Pavement Performance under Different Axle Configurations: Fid-Bau Portal

Evaluation of Stabilized Weak Subgrade Material on Pavement Performance under Different Axle Configurations

Quadri, H. A. / Abiola, O. S. / Odunfa, S. O. / Azeez, J. O.

This study evaluated the performance of stabilized weak Ota-Idiroko road subgrade material to fatigue failure under heavy axle configurations and at different pavement layer thickness combinations. The subgrade was stabilized with calcium carbide waste (CCW) by weight (0, 4, 8, 12, 16, and 20%) and the blends were subjected to California bearing ratio (CBR), elasticity modulus (E), and density tests. Parameters from these tests were employed to simulate the horizontal tensile strain at the bottom of asphaltic cover under the application of Truck 2 and Truck 7 Axles for each blend from where number of load repetitions to fatigue failure (N_f) and damage factor due to fatigue failure (D_f) were determined using ANSYS finite element software. The stabilized blends were modeled to have a uniform thickness of 1,000 mm and an overlying layers of three different pavement layer thickness combinations of Subbase (150, 200, 250 mm), Base (150, 200, 250 mm) and asphaltic cover (40, 60, 100 mm) to represent Pavement layer thickness variations 1–3 respectively. Results showed that stabilization of weak subgrade with all blends of CCW effectively reduced horizontal tensile strain at the bottom of asphaltic cover, damage factor due to fatigue failure and increased the number of load repetitions to fatigue failure under the applications of Truck 2 and Truck 7 Axles with the blend of S + 12% CCW exhibiting best performance which was majorly a function of its high Elasticity modulus (125.27 MPa).