Research Of Rapid Repair Materials For Bridge Expansion Joints Rehabilitation

Bridge telescopic device is an important part of the bridge structure,but also easier to damage the components.With the rapid development of China's economy,the vehicle overloading situation is serious,coupled with the erosion of the rain,the ambient temperature changes and other natural factors,the bridge expansion device prone to local damage,affecting the overall service life of the bridge.In the replacement of telescopic device construction usually need half closed road,causing traffic congestion.Therefore,in the minimization of adverse social impact under the premise of rapid expansion of the expansion joints to reduce the concrete curing cycle is an urgent need to solve the technical problems.In this paper,focusing on the structural characteristics of the telescopic device and the rapid maintenance of the concrete in the transition zone,a quick fixation concrete suitable for the replacement of the highway bridge telescopic device is preferred.In this paper,the main types and failure modes of the bridge telescopic device are summarized.The process of the concrete from the crack to the loss bearing function in the transition zone of the bridge telescopic device is summarized.The reason of the damage of the expansion joint is analyzed from the aspects of design,construction and management.The discriminant indexes and scheme optimization principles of different types of expansion joints are put forward.This paper puts forward the technical indexes that the concrete should be repaired in the transition zone of bridge expansion joints,and the repairing materials suitable for bridge expansion joints are obtained through the mortar strength test of ordinary silicate,sulphoaluminate cement and CRM repair material.Through the orthogonal test,the concrete mix ratio of CRM concrete is optimized,and the mixing ratio of the concrete with 8h open traffic is obtained.A series of road performance comparison tests were carried out on the rapid repair materials.The properties such as strength,shrinkage,abrasion resistance and bond strength were evaluated.The experimental results show that the early strength of CRM concrete is high,and 10% of the fly ash can be added to maintain the higher strength.The shrinkage performance and abrasion resistance are better than ordinary cement concrete.By improving the interface roughness and coating Brush interface agent can improve the bonding strength with the old concrete and asphalt concrete.The study of the expansion joints in the expansion zone of concrete repair materials can significantly reduce the bridge expansion joints maintenance of closed traffic time,bring good social benefits,while cement concrete pavement repair materials provide a basis for research.