Effect Of Recycled CFRP On The Mechanical Properties And Durability Of Concrete And Its Microscopic Mechanism

With the rapid development of science and technology,requirements for material performance are improved.Carbon fibre-reinforced polymer(CFRP),as a highperformance material,has been widely used in many fields.However,a large amount of waste material is generated during the production process of CFRP,which can cause serious environmental problems and waste of resources if not properly handled.Therefore,from the perspective of environmental protection and resource saving,this paper processed the CFRP prepreg cloth scraps and mixed them into C30 ordinary concrete,and studied the working performance,mechanical performance and durability of concrete of recycled CFRP.The mechanism of recycled CFRP in ordinary concrete was further analyzed by scanning electron microscope,thermogravimetric analysis,Xray powder diffraction and other testing methods.The experimental results show that the overall performance of concrete of recycled CFRP is better than that of pure concrete in terms of mechanics,especially in terms of fracture resistance,the best can be enhanced by 49.01%.However,the compression resistance is only slightly enhanced.In terms of durability,recycled CFRP may reduce the density of concrete,resulting in carbon dioxide more easily to invade the concrete,so recycling CFRP concrete is easier to carbonize than plain concrete.However,the recycled CFRP limits the crack propagation in the concrete during the sulfate corrosion process,which makes the concrete of recycled CFRP more resistant to sulfate than the plain concrete.In order to explore the influence of recycled CFRP on ordinary concrete at the microscopic level,a series of tests were conducted in this paper.The test results show that recycled CFRP shows chemical inertness during the hydration process inside concrete,so no new hydration products are produced,but the appropriate amount of fiber can accelerate the hydration rate.The porosity of concrete of recycled CFRP is higher than that of plain concrete.The surface of recovered CFRP after mechanical treatment is uneven,with many channels similar to grooves.Recycled CFRP has a bonding force at its interface with cement,which can limit the development of cracks,change the trend of cracks,and a crack into multiple when the concrete is subjected to external force,thus playing a role in enhancing the effect.