Mitigating reflective cracking in composite pavements through the use of a ductile concrete interlayer

Abstract

Reflective cracking of composite pavements refers to the phenomenon that cracks propagate from a deteriorated Portland cement concrete (PCC) slab to the newly constructed hot mix asphalt (HMA) overlay at locations where there are joints and cracks in the underlying PCC pavements. It is one of the predominant failure modes of composite pavements, often resulting in premature failure and limited service life of HMA overlays. To improve the resistance of composite pavements to reflective cracking, in this study, a new ductile concrete interlayer made of Engineered cementitious composite (ECC) was proposed and experimentally evaluated. ECC is a type of high-performance fiber-reinforced cementitious composites that features high tensile ductility, high fracture resistance, and high deformation capacity. It is expected that by constructing a thin ECC interlayer between exisiting PCC pavement and HMA overlay, reflective cracking can be prevented or significantly delayed. In the current paper, small lab-scale sandwich-type composite pavement specimens with and without ECC interlayers were constructed and tested under fatigue loadings that simulates repeated traffic loadings. The experimental result indicated that the ECC interlayer successfully suppressed reflective cracking and altered the failure mode of the composite pavement. As a result, specimens with ECC interlayers exhibited significantly (30 to 47 times) higher fatigue life as compared to the control specimens without interlayers. This result demonstrated that ECC interlayer is effective in reflective cracking mitigation.