The Study On Bonding Behaviors Of Reactive Powder Concrete And Ordinary Concrete

The reactive powder concrete (RPC) has some advantages including super-high strength, toughness, durability and good environmental-friendly property, so it is of vital significance to use RPC to reinforce concrete structure in engineering practice. In use of RPC to reinforce concrete structure, the bond issue of RPC and ordinary concrete should be taken into consideration.This paper conducted splitting tensile tests, Freeze-thaw split test and binding trabecular bending text of reactive powder concrete and ordinary concrete bonding composite cube specimens, observing the changes of specimen’cracking process and failure pattern with the transform of interface geometry features, bonding method, the strength of ordinary concrete and steel fiber content. By changing the bonding interface orientation (horizontal and vertical), dry wet curing methods, casting process and the bonding gap approach, analyzed and measured the influence of adhesive specimens of splitting tensile strength,flexural performance and frost resistance. All of these laid the foundation for the application of active powder concrete reinforcement in concrete structures.Through the test analysis we found that the steel fiber in reactive powder concrete could improve the interface roughness, reduce reactive powder concrete shrinkage, improve mechanical bite force, and also have the crack resistance, which could improve the bonding behavior and frost resistance after incorporating in ordinary concrete.The improvement of both interface roughness and the ordinary concrete strength could significantly develop the bonding behaviors. But for ordinary concrete itself, after arriving in a certain intensity strength, it was limited to improve the overall adhesive performance.Under the action of freeze-thaw cycle, the bonding surface damage of the bonding component was far more than the freeze-thaw cycle damage to reactive powder concrete or ordinary concrete. What’s more, it had no effect to improve the bonding specimens’ frost resistance by enhancing the strength grade of ordinary concrete.In addition, construction technologies such as water retention on bonding interface to increase humidity, vertical pouring to improve tightness and processing on bond gap could also greatly improve the bonding behavior and frost resistance.