Study On Application Of Multi-Functional FRP Reinforced Concrete Structure

Fiber Reinforced Polymer(FRP)is composed of fibrous material and matrix material according to a certain process,which couples the properties of the matrix material and the enhanced phase.Adding a second enhanced phase can make FRP multifunctional.The carbon nanotubes(CNTs)are dispersed in the epoxy resin(EP)matrix,and the modified matrix(CNTs-EP)with good mechanical properties,electrical conductivity and force sensitivity can be obtained.The FRP prepared by this substrate will have good self-sensing characteristics of stress-resistance,which makes it possible to monitor the self-damage and sense the stress state of concrete structures.In order to realize the multi-functionalization of FRP,this paper select the carbon nanotubes as reinforced materials to modify EP.CNTs-EP was applied to the preparation of CFRP and this paper further explored the effect of CNTs-CFRP on its own damage and structural stress monitoring and the effect of CNTs-EP on force sensitive performance.In this paper,the experimental organization method is used to evaluate the selection,preparation,basic performance and performance of the composite materials.The specific contents are as follows:1.This paper first discussed the CNTs dispersion principles and methods,and selected three roller rolling,ultrasonic treatment and external dispersant for the integrated dispersion of carbon nanotubes.The CNTs-EP with a good dispersion was successfully prepared,while characterizing by SEM.2.In this paper,two kinds of modified substrates were prepared by CNTs,the mixture of CNTs and carbon fiber(CF)powder.Effect of electrical properties and the mechanical properties of the resin matrix were studied by measuring the resistance of the modified matrix and the uniaxial tensile test,which were in different addition amounts.Then,the influence of the content on the force-sensitive properties was studied by resistance-strain curve of the modified resin matrix which conducted by two kinds of cyclic loading conditions.Combined the resistance-strain curve with SEM images,the influence mechanism of carbon nanotubes on the resin matrix was analyzed.The experimental results show that the CNTs-EP with the proper amount of CNTs has good mechanical properties and force sensitive properties.3.The former carbon nanotubes modified matrix was used to prepare modified CFRP.The effect of carbon nanotubes on the force-sensitive properties of CFRP was investigated by loading experiments under two cyclic conditions.Combined with the resistance response curve and stress-strain curve,the effect of CNTs-CFRP on the internal damage perception was analyzed.Finally,through the experimental study on concrete surface of modified CFRP,the perceived effect of modified CFRP on the impact load was tested.The experimental results show that the proper amount of carbon nanotubes can enhance the force sensitivity of CFRP,and the CNTs-CFRP can effectively perceive the internal damage and external load excitation.