| Anchorage technologies have attracted increasing attention in the field of modern reinforcement technology, among which the most widely used one is the chemical anchorage technology. It lays foundation for the subsequence reinforcement treatment processes by fixing rebar and concrete together with anchor adhesives. Wherein the performance of anchor adhesives used in this process has significant influence on the fields of applications of anchorage technology. To get a better understand of influence of anchor adhesives, three kinds of high performance epoxy type anchor adhesives were synthesized and their practical performance were tested. The data got from the practicing test is summarized and studied in this paper, which can provide theoretical foundation for the applications of anchorage technologies.Firstly, a waterborne curing agent, which is insoluble in water and is capable of rapidly react with epoxy resin, was synthesized by modifying diethylenetriamine through Mannich reaction. Orthogonal experimental deign was applied to optimize the synthetic compositions. This anchor adhesive can completely solidify under water and give a steel-to-steel shear strength of 24.50MPa. In practice, pour the anchor adhesive into a water-filled hole which is made of C30 concrete, then insert rebar, the depth of rebar is 12 times the diameter of it. After completely solidify, the average bearing capacity is 47.00kN, approximately equal to the fracture strength of rebar,46.80MPa, which can maximize the strength properties of the adhesive.Another organic monocomponent adhesive was prepared. Based on the polymerization mechanism, a BS-Hydracetin-CHP redox system was designed to accelerate the generation of free radicals. According to the curing reaction kinetics, the reaction activation energy was tested as Ea=46.43kJ/mol. Also, the curing reaction kinetics model can serve as a circumstantial evidence to prove that this reaction is a polymerization process and is able to occur spontaneously. The relationship between the additive amount of each component and the curing time was also studied. It was found that the join of initiator and accelerant has little influence on the storage life of the anchor adhesive, while adding stabilizer can remarkably improve the stability during storage. This organic monocomponent anchor adhesive can give a steel-to-steel sheer strength of 14.50MPa, and is capable of 30 minutes storage under 80 ℃. In practice, the depth of rebar is 12 times its diameter, and the average bearing capacity is 44.20kN which is greater than the strength of national A grade plastic and satisfies the requirements.Finally, a anchor adhesive with high bond strength and anti-aging properties was prepared. In the synthesis process, the epoxy modified by PU-EP and by CTBN-EP were prepared, respectively, to get better toughness and modified performance. It is found that the maximum steel-to-steel sheer strength can be achieved by adding 15% CTBN-EP. After mixing the flexibilizer with other components, a steel-to-steel shear strength of 34.50MPa can be obtained and the aging ratio can be reduced to 34.8%.In practice, when the depth of rebar is 8 times its diameter, the average bearing capacity is 47.50kN, and the rebar is brocken. |
