Thermal reflective cracking of asphalt concrete overlays


Dave EV, Buttlar WG. Thermal reflective cracking of asphalt concrete overlays. International Journal of Pavement Engineering [Internet]. 2010;11 (6) :477 - 488.


Reflective cracking of asphalt concrete (AC) overlays is one of the most extensive pavement distress and damage mechanisms in composite pavement structures. Numerous studies have been performed to evaluate the reflective cracking potential of AC overlays under different loading scenarios. Most of these studies have focused on reflective cracking due to tyre loading. A very limited amount of work has been performed to evaluate non-load-associated thermal reflective cracking of overlays. Thermal reflective cracking mechanisms have been studied and are described in this paper using recently developed hot-mix asphalt mixture tests and fracture models. A series of finite-element-based pavement simulations were performed in an effort to better understand thermal reflective cracking mechanisms as a function of several key material and pavement structure variables. The enhanced integrated climatic model was used to estimate pavement temperature gradients as a function of position and time. A fracture mechanics-based cohesive fracture model was used for the simulation of damage and cracking, which was tailored for use with quasi-brittle materials such as AC. The pavement simulation model utilises creep and fracture properties from American Association of State Highway and Transportation Officials and American Society for Testing and Materials-specified tests and analysis procedures. Three asphalt mixtures manufactured with Superpave low-temperature performance grades of -22, -28 and -34 were studied in pavement structures with three distinct overlay thicknesses. Simulations were conducted with three Portland cement concrete (PCC) slab conditions to study the effects of joint spacing and rubblisation on thermal reflective cracking. The simulation results provide a new insight towards the mechanisms underlying the development of thermal reflective cracking. The curling of PCC slabs due to temperature differential and joint opening caused by pavement cooling was found to be critical in the initiation of thermal reflective cracking. This effect is greatly minimised or eliminated in the case of pavement rubblisation. © 2010 Taylor & Francis.


American Association of State Highway and Transportation Officials;American society for testing and materials;Asphalt concretes;Asphalt mixture;Asphalt overlay;Climatic models;Cohesive fracture model;Composite pavements;Damage mechanism;Finite-element;Fracture model;Fracture property;Hot-mix asphalt mixtures;Joint openings;Joint spacing;Key materials;Low temperature performance;Numerical simulation;Pavement distress;Pavement simulation;Pavement structures;Pavement temperature;Portland cement concretes;Quasibrittle material;Reflective cracking;rubblisation;Simulation result;Superpave;Temperature differential;Tests and analysis;