Evaluation of cracking resistance potential of geosynthetic reinforced asphalt overlays using direct tensile strength test

• Published in: Construction & building materials Vol. 162; pp. 37 - 47
• Main Authors: Kumar, V. Vinay, Saride, Sireesh
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 20.02.2018; Elsevier B.V
• Subjects: Analysis; Asphalt; Asphalt overlays; Concrete cracking; Digital image correlation; Direct tensile strength test; Fracture energy; Geosynthetic interlayers; Geosynthetics; Mechanical properties; India; Direct tensile strength test; Geosynthetic interlayers; Asphalt overlays; Digital image correlation; Fracture energy
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2017.11.158

•The geosynthetic reinforcement improves the cracking resistance potential of asphalt overlays.•The performance of specimens conditioned at lower temperatures are superior to that conditioned at higher temperatures.•Digital imaging technic effectively provides the crack propagation patterns and the mobilized strains.•The tensile strains in reinforced specimens are lower than the unreinforced specimens.•The presence of interlayers could accelerate the delamination of pavement layers, if not addressed properly. The study aims at evaluation of cracking resistance potential of geosynthetic reinforced two-layered asphalt specimens under direct tensile strength test (DTT), conditioned at different temperatures (20 °C, 30 °C and 40 °C). Apart from determining the tensile stiffness of the asphalt specimens, the DTT is also capable of evaluating the cracking resistance potential through estimating the energy dissipated during cracking. The potential to resist reflection cracking may be improved with the inclusion of geosynthetic-interlayer. To understand the crack propagation patterns and to quantify the resulting strain fields, digital image correlation (DIC) technique was employed. The geosynthetic-interlayers used in the current study consist of a glass-grid composite (GGC), a bi-axial polyester grid coated with polymer modified binder (PE), a biaxial polypropylene grid (PP) and a woven geo-jute mat (GJ). Results indicate that all the specimens conditioned at a temperature of 20 °C have shown better resistance to the cracking than the specimens conditioned at 40 °C. The specimens with GGC interlayer were effective in controlling the cracks as they could mobilize high tensile strength at a low strain value. The digital image analysis was instrumental in quantifying the tensile strains developed in the pavement layers. It was noticed that the control specimens have developed a tensile (vertical) strain of 6.85% at 20 °C against 2–4% in the specimens with geosynthetic-interlayers.