Surface Modification of Carbon Fiber by Polymer Emulsions and Mechanical Property of Modified Carbon Reinforced Concrete

Four kinds of polymer emulsions were coated on the surface of coal pitch carbon fiber using atomized flow static coating method. The surface morphology of the carbon fiber after modification was analyzed by fluorescence microscope. The tensile strength of coated carbon fiber in the cement mortar and the mechanical property of the coated carbon fiber reinforced concrete were tested. The results showed that all the polymer emulsions were coated successfully on the surface of carbon fiber. The tensile strength of the coated carbon fiber in the cement mortar increased obviously, specially for the carbon fiber coated by meta chloride copolymer emulsion, whose tensile strength improved by 61%. The tensile strength of the coated carbon fiber reinforced concrete increased by 11%, the fracture energy increased by 47% and the max crack width increased by 18.5% when the content of the carbon fiber coated by meta chloride copolymer was 1.7 kg/m(3).