| In order to solve the problem of steel bridge deck fatigue cracking and early damage of flexible pavement,the research team of the author put forward a steel-ultra-thin UHPC light composite deck system based on a series of theoretical analysis and material performance research.The strong adhesion of cement-based UHPC layer to asphalt wear layer in this new system is one of the main technical problems to be solved.It is essential for extending the service life of bridge deck,protecting UHPC structural layer,avoiding slip,delamination and other diseases..In this paper,a series of experimental studies are carried out from the mechanical properties of UHPC-asphalt wear layer domestic epoxy interface agent.The main work is as follows:The mechanical properties of UHPC underlayer and asphalt wear layer domestic epoxy interface agent were studied by means of indoor mechanical property test.The results show that the ambient temperature has a significant effect on the mechanical properties of domestic modified epoxy interface agent,and the interface bond strength is At high temperature(60 ° C),the temperature is significantly lower than that at normal temperature(20 ° C);after adding silica,the bonding property of epoxy interface agent is obviously improved;the interfacial bond strength of the interface agent does not increase with the amount of spreading.Continued to increase.Domestic epoxy interface agent 2766-II and imported 202 have high interfacial bond strength.Although the bonding performance of epoxy interface agent is lower under high temperature(60 °C),it is still superior to asphalt binder;compared with imported 202,domestic interface agent 2766-II has the same interface bond strength at room temperature;At high temperature,the interfacial bonding strength of domestic interface agent 2766-II is higher than that of imported 202,and its high temperature stability is better than that of imported 202;temperature has a significant effect on the mechanical properties of epoxy interfacial layer.Attention should be paid to the suitability of epoxy interface agents under high temperature conditions.The effect of freeze-thaw cycle on the bond strength of the interface agent is greater than the high temperature cycle of the chloride salt.With the increase of the number of cycles,the interfacial bond strength of the domestic interface agent 2766-II is much lower than that of the imported interface agent 202,indicating that the aging resistance of the domestic interface agent 2766-II is significantly better than that of the imported 202.The correlation between the adhesion drawing and the drawing of the composite test piece is good.In view of the finite element simulation calculation results of the actual bridge of the Dongting Lake Second Bridge,the domestic epoxy interface agent 2766-II and the imported epoxy interface agent 202 can meet the interlayer stress under normal temperature and high temperature conditions under the action of the most unfavorable load combination.Required and have a large enough safety factor.The interfacial bond strength of domestic epoxy interface agent 2766-II under normal temperature conditions is comparable to that of imported epoxy interface agent 202.The interfacial bond strength under high temperature conditions is higher than that of imported 202,and its aging resistance is also significantly better than that of imported 202.The shear strength and drawing strength after 15 cycles are respectively above 2.70 MPa and 2.63 MPa,and the integrated unit price is about 40% lower than that of imported epoxy interface agent 202.The construction process is simple and the dosage control is accurate,which can replace imported products. |
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