Study On The Strength And Smart Property Of The Hybrid Fiber Enhanced Electrical Cement Composite

Coating with a thin layer of copper on the surface of polypropylene fiber by way of electroless copper plating having silver catalysts for electrical polypropylene fiber,add this fiber in steel fiber enhanced cement-based composite,The hybrid fiber enhanced electrical cement composite(HFEEC) were prepared,and studied on the strength properties and smart property of the material,researched the relationship of fiber content and the electrical conduction of the material,Strength Properties,smart property,shooting at developing a structural functional integration material having good strength properties,that can monitor the health of concrete structure in enlistment,and forecast residual life of material suffered natural calamities.The following conclusions have been obtained in this thsis:1.The principle,smart property,preparing technique and the main factors which influence the conductive properties of the concrete are discussed.It is found that the dispersion of fibers is the key problem to prepare HFEEC.The content and the degree of dispersion of fibers,the water/cement ratio,the sand/cement ratio and the curing age have obvious effects on the resistance of HFEEC.2.The piezoresistivities of HFEEC under monotonic compressive loading,cyclic loading with increasing amplitudes,cyclic loading with constant amplitude and the dead loading are investigated.The experiment results reveal that the resistance changing of HFEEC can reflect quantitatively the loading on it,so the HFEEC can be used as piezoresistive sense organ.3.The change of resistance of HFEEC beam under bending load is discussed.It is found that the resistance decreases slightly with the increasing of the loading at the beginning,but when the loading increases to a certain value,the resistance changes sharply and then turn slowly again until the beam fracture.The change of the resistance indicates the formulation and the propagation of the micro-crack in the HFEEC,so HFEEC has the ability of self-diagnose.4.The change of resistance in HFEEC under fatigue compress loading is studied.At first, HFEEC is pressed densely,its internal crack flaw is closed and as a result the resistance of HFEEC decreases.The phenomenon indicates that the damage occurs under the fatigue loading and the damage is accumulated during the fatigue process.5.The compressive strength and flexural strength test of the HFEEC shows that,the hybrid fiber has greatly improved the strength properties of HFEEC.