Study on Hot-Mix Epoxy Resin Based on Glass Transition Temperature and Its Application for Steel Bridge Deck Pavement

Abstract

There are many kinds of hot-mixed epoxy resins on the market with uneven performance, which makes it difficult to select the excellent performing material. This study investigated the effects of glass transition temperature (Tg) on epoxy resins, epoxy asphalts, and epoxy asphalt mixtures, aiming to confirm the Tg is an effective way to quickly select optimum epoxy resin materials. Specifically, the macromechanical properties, microproperties, and rheological properties of epoxy resins, epoxy asphalts, and epoxy asphalt mixtures were evaluated by a tensile and viscosity test, a dynamic mechanical thermal analysis test, a scanning electron microscope (SEM) test, and a dynamic shear rheometer test. Results indicate that the performances of epoxy resins, epoxy asphalts, and epoxy asphalt concretes have closely related with Tg. With Tg increasing, the tensile strength, Marshal stability, and dynamic stability are increased, while the elongation at the break, flexural tensile strains, fracture energy, and viscosity are decreased. In addition, the enhanced Tg may boost the deformation resistance of epoxy asphalts. Furthermore, the activity energy of HB, CW-HBP, and TAF is −42.86 kJ/mol, −40.79 kJ/mol, and −53.97 kJ/mol respectively, which demonstrate that Tg has no correlation with the activity energy. Besides, according to the SEM test result, the lower Tg can make epoxy resins experience ductile fracture, while higher Tg can make the HB epoxy resin experience brittle fracture. Finally, the Tg can be used to qualitatively compare and quickly select the optimum hot-mix epoxy resin used in long-span steel bridge deck pavement.