Study On Shear Behavior Of Young And Old Concrete Bonding Interface

In recent years,the reinforcement and repairment of concrete structure engineering is becoming the trend of construction industry.The bonding quality of new and old concrete has great influence on the reinforcement effect,which directly affects the reliability and service life of the structure.Along with the development of the technology of planting reinforcing bar,it begins to enter the researchers view and is used in engineering gradually which can improve the properties of the surface bonding.In China,the applications and research of plant reinforcing bar started late,which mostly is concluded in the experimental research and engineering practice.Limited by form and size of specimen,the test conditions and other factors,relative research is lack and has not formed a complete theoretical system yet.It is not enough that many scholars study on influence factors such as surface processing,steel ratio and planting bar arrangement.In addition,the calculation of shear strength is obviously different.Following aspects are discussed in this paper:A digital image method was put forward and the roughness effects on the bond property of the young and old concrete has been analyzed in this paper.Based on the digital image method,the calculation method of shear friction coefficient is proposed.We design 16 Z-cut specimens with 8 series,at the same time increased the size of the specimens to embed several bars,considering the effects of the diameter of the bars,ratio of reinforcing bar and arrangement of the bars.Large area concrete pavement slab model was established based on ANSYS software and analyzed the performance of the pavement slab model under vehicle load.Moreover,we study the influence of planting bar rate of large steel bar on shear performance.Combined with the actual project,we puts forward the construction of cement concrete pavement slab design based on the results of test and simulation.