Study On The Interface Damage Of Concrete-reinforce And Transport Properties Of Protective Layer

The interface of reinforced concrete and the transport property of the concrete cover are the key to influence the mechanical property and durability of concrete.Aiming at the two influence factors of different water-binder ratio and fly ash content,a number of studies on bond damage,protective layer injury and transport property were carried out from mesoscopic to macroscopic,calculated and verified by using the finite element software.The hydration process of different cementitious sysytems were quantitatively studied by using VCCTL virtual test software,combining with the actual production process and mix proportion to obtain the C-S-H gel quantities?pore structure and mechanical properties of concrete.By comparing and analyzing the date obtained from the electrochemical impedance spectroscopy technique and splitting tensile test method,so as to more systematically research the cementing property of the hydration products of the cementitious material.It can be seen that the decrease of water-binder ratio and the proper incorporation of fly ash can effectively enhance the cementing performance of hydration products,further optimize the internal structure and improve the performance of concrete,and also provide a reference for the research of bond damage and transport property.Subsequently,the tests were tested by combining with the technology of acoustic emission and electrochemical impedance spectroscopy under the push-out test and the four-point bending test at the same time.Emphatically studied the relationship between the resistance and capacitance obtained by using electrochemical impedance spectroscopy of the interface damage,as well as the effect of different cementitous material systems on bond damage.It is found that with the deepening of the bond damage,the resistance of the interface increases and the capacitance decreases,moreover the low water-binder ratio and reasonable amount of fly ash can enhance the anti ability of bonding damage.At the same time,the four-point bending test was simulated by ANSYS finite element software,and the results match the test.Finally,comprehensively applied the acoustic emission and electrochemical impedance spectroscopy,to explore the transport properities of protective layer,and research the relationship between the damage degree and transport properties.The results show that reducing the water-binder ratio and proper addition of fly ash can improve the transport properties of protective layer.With the increase of the damage degree,the transport properties will deteriorate.Research shows that the electrochemical impedance spectroscopy and acoustic emission can be well applied to the reinforced concrete interface damage and transport property.These two tests can be complementary to each other and obtain more abundant information than other experimental methods.Therefore,they can provide new methods for the follow-up study.