Study on direct coal liquefaction residue influence on mechanical properties of flexible pavement

To study the influence of DCLR (direct coal liquefaction residue) on mechanical properties of flexible pavement, the DCLR/compound DCLR modified asphalt mixture was prepared. The 15 °C and 20 °C compression resilience moduli of DCLR/compound DCLR modified asphalt mixtures were measured using the uniaxial compression test. The influences of DCLR/compound DCLR modified asphalt mixture on deflection, upper layer thickness, and bending flexural tensile stress of layer bottom were analyzed using Bisar3.0 and HPDS software. The test results show the DCLR/compound DCLR modified asphalt has higher compression resilience modulus. Due to higher resilience moduli of DCLR/compound DCLR modified asphalt mixture, they can be used as bottom layer in pavement. Under the identical loadings, the upper layer thickness can be reduced by adding DCLR and compound DCLR. If the upper layer thickness is same, the bending flexural tensile stress of layer bottom and deflection will decrease significantly.