Study On Durability Of Ultra Violet Cured GFRP And Its Strengthened Concrete Beam

Ultra Violet (called for short"UV") curable resin is also called photosensitive resin which can be cured under ultraviolet quickly (generally, < 1min). It has many advantages such as much lower Volatile organic compounds and energy saving. By now, UV curing resin systems have been widely used to coat various substrates such as paper, metal and ceramics, etc. The quick curing of UV resin compared with the traditional resin indicates it's attractively potentials in the field of civil engineering. UV curing resin can be used to repair and strengthen infrastructures (such as bridges, dams, etc.) in a very fast way which is of great significance to the cases of emergency disaster relief and rapid transit recovery. It also brings convenience to the construction. For example, it can reduce production cost and improve production efficiency and realize low-carbon economy.Environment of civil engineering structure application is complex such as hot and humid, freeze-thaw cycle, alternating wet, seawater erosion etc. As a kind of new structural FRP composites, its durability under various severe environments is the foundation for its design, application and wide acceptance. In view of this, the present paper will focus on the following topics:(1) Based on the performances of UV cured resin system, the compositions of UV resin, preparation methods, curing conditions are optimized. Experiments show that comprehensive performance of UV curing resin system is the best when epoxy acrylates content is 60% and the time for curing is 25 s.(2) Making UV cured GFRP by wet layups and establishing its degradation law of tensile properties when subjected to water and alkaline solution immersion.(3) The effect of combined sustained bending strain and alkaline immersion on the durability of UV cured GFRPs and its strengthened concrete beams. Experiments show that bending strain and alkaline immersion have great influence on bond between UV curing resin and concrete and bond failure is leading the failure mode.The innovation of paper is development of a UV curing GFRP being studied in its performances related to the civil engineering applications. In addition, the durability of UV cured GFRP and its strengthened concrete beams have been studied on their durability performances under sustained bending strain and harsh environments. Parameters of degradation UV curing GFRP are introduced into Local shear sliding principle based on fracture mechanics which can quantitatively and qualitatively evaluate bond degradation between UV curing resin and concrete.