Evaluation of Bonding Interior Layer Failure Strength Modes in the Composite Pavement

Abstract

A tack coat is a minimal coating of asphalt cement, cut-back asphalt, or asphalt emulsion to an existing pavement surface between layers to guarantee proper bonding between the two layers and longitudinal and transverse Joints. Numerous researchers have assessed interlayer adhesion employing failure-mode behavior tests, such as pull-off, direct shear, and torsion testing. This study aims to quantify the best tensile resistance obtained using PG (76-10) modified asphalt cement with polymer 4.5%, Sikadur®-31 CF (S.E) usage at elevated temperatures between +25 °C and +45 °C, an epoxy-resin-based adhesive, and repair mortar with specific fillers. And Nitomortar TC2000 epoxy (F.E) resin-based sealing compound from Fosrok Company. All are applied on concrete surfaces at a rate of 0.5 kg/m2 except for Nitomortar, which depends on layer thickness ranges between (1-2.5) mm instead of the application rate. The Proceq DYNA Z16 pull–off tester is used to measure the tensile strength at a rate of 2lb/s. It is found that the average tensile strength of the tack coat materials is (0.607, 1.481, 2.622) MPa, respectively. It concluded that (F.E) epoxy has the maximum tensile strength. Also, adding polymer to asphalt increased adhesiveness. Failure strength modes of interior bonding varied between cohesive failure adhesive, adhesive failure, and cohesive failure in the concrete substrate.