Experimental Study On Flexural Behavior Of Concrete Narrow Beams Hybrid-strengthened With ECC-based TRC Plate

When ECC based TRC plate is used for the reinforcement of concrete flexural members,although it can avoid the use of epoxy organic glue at the interface and improve the durability of the interface in harsh environment,it is difficult to solve the problem of interface peeling,which is not conducive to the efficient utilization of materials and the safe service of the structure.Therefore,in order to improve the durability and bearing capacity of the strengthened structure at the same time,this paper combines ECC based TRC plate reinforcement with the self-locking anchorage technology developed by the research group,and carries out experimental and theoretical research from the multi-level of material interface structure.The main work and research results are as follows:(1)The grid self-locking reinforced tensile test is carried out to realize the effective combination of grid and self-locking anchorage technology.Research and development of modified ECC based TRC board: carry out the mix proportion design of ECC matrix.When the silica fume content is 0.2 of cement and the steel fiber content is 2%,the overall performance of ECC based board is better.(2)Carry out the experimental research on the tensile properties of ECC based TRC plate,study the effects of different grid layers and self-locking winding treatment(anchoring effect)at the end of the grid,and clarify the improvement effect of the tensile properties of TRC plate under different factors.Grid end treatment can improve the grid synergy within TRC and enhance the ultimate strength of TRC.(3)The experimental study on the shear performance of ECC base TRC slab concrete interface was carried out to explore the effects of different TRC slab thickness,different anchorage methods and anchorage positions,and the typical load slip curve of the specimen was analyzed.When there is an end anchor,the failure mode of the specimen is improved and the stress level is improved accordingly.Based on the experimental results,the constitutive model of interfacial bond slip relationship is deduced.(4)The experimental study on flexural behavior of concrete beams strengthened with ECC base TRC slab under end anchorage was carried out.The effects of different grid layers,end anchorage and TRC plate bonding length are investigated,and the load deflection curve,characteristic load,crack development law and failure mode of the strengthened beam are analyzed.The failure mode of reinforced beam with concrete anchor is improved,and the characteristic load(cracking,yield and limit)of reinforced beam is increased by 50%,26% and 62%.Through the theoretical calculation of the characteristic load of the strengthened beam through the existing formula,the effectiveness of the formula is verified.There are 86 pictures,24 tables and 68 references in the thesis.