EARLY-AGE MECHANICAL BEHAVIOR AND ACTION EFFECT OF CEMENT CONCRETE PAVEMENT WITH ASPHALT INTERLAYERS

By using three-dimensional finite element analysis, structural behavior of early-age Portland cement concrete pavement (PCCP) with asphalt interlayers was studied. The effects of the asphalt interlayers on the formation process as well as the early-age behavior of PCCP were analyzed with respect to its mechanical properties. The analysis results show that the combined action of built-in temperature in early age, concrete's creep, hardening process and the environment fields cause more significant early-age curling and interfacial debonding at the slab corners. Such effects were however neglected by traditional theories. PCCP with asphalt interlayers has smaller debonding areas and larger curling deformation compared with the directly-overlaid pavement without asphalt interlayers. In addition, combining with specific heavy traffic, structure effect of the early-age curling and debonding may have an unfavorable influence upon fatigue life of pavement structures with asphalt interlayers. On the basis, it is suggested to use bases with larger stiffness in PCCP with asphalt interlayers. In particular, the thickness of the asphalt interlayers should be less than 30 mm, and the elastic modulus of asphalt mixture should be of low values.