Research On The Performance Of Electric Induced Hardening Carbon Fiber Reinforced High Performance Concrete

With the continuous development of social life,people have increasingly high requirements for cement-based materials,but traditional cement-based materials have low tensile strength,poor toughness,poor durability and other characteristics to a large extent limit its application.As a new cement based material with high strength and durability,reactive powder concrete(RPC)has attracted wide attention.Traditional curing methods of RPC mainly include high-temperature steaming curing method and autoclaved curing method,but these curing methods have high requirements on the test environment,leading to the failure of on-site construction of RPC,which greatly limits its application.In this paper,high performance concrete mixed with conductive filler has the characteristics of good electrical conductivity,which provides an effective electric induced curing method for the rapid formation of the strength of high performance concrete(HPC).Main contents are included as follows:Firstly,a constant electrical power was applied to the sample during the experiment to generate ohmic heat,thus accelerating the hydration reaction of the cement and rapidly forming the strength of the structure.As a conductive material,carbon fiber will form a conductive path in fresh paste,thus reducing the resistance and improving the bending resistance of the sample.The effects of different raw material dosage and preparation technology on initial resistivity of fresh paste were analyzed.On this basis,a numerical model based on the percolation threshold theory was established to simulate the bridging effect of carbon fiber in the sample,and compared with the experimental results.Secondly,a theoretical prediction equation based on heat transfer was proposed to deduce the relationship between the curing temperature and the electrical power of the sample placed in the constant temperature curing box,providing a theoretical prediction model of power-temperature that can accurately predict the final curing temperature of the sample.Finally,mechanical properties and microstructure of HPC samples cured under different curing conditions were characterized in a series of ways,including SEM,TG-DSC and FTIR.This paper provides an effective curing method for rapidly forming the strength of high performance concrete.