Experiment On Bond Properties Between BFRP-FRCM Composite Layer And Aerated Concrete Block

Basalt Fiber Reinforced Polymer-Fabric Reinforced Cementitious Matrix(BFRP-FRCM)is widely used in the reinforcement of existing masonry structures,but the bond properties between different materials determines its reinforcement effect.Therefore,in this paper,the bond properties of BFRP-FRCM composite layer and aerated concrete block is taken as the research object,and the experimental investigation and theoretical analysis of BFRP-FRCM composite layer reinforced masonry structure are carried out.Single-sided shear tests were conducted on single block specimens and specimens with mortar joints to explore the influence of bonding length of composite layer,number of basalt mesh layers and different types of fibers(polyvinyl alcohol fibers and polyethylene fibers)in mortar on bonding properties,and to obtain the bond-slip intrinsic structure model,which provides a reference for the application of BFRPFRCM composite layer reinforced masonry structure.The specific research results are as follows:(1)Single-sided shear tests on individual block specimens and masonry specimens with mortar joints reveal that the specimens exhibit brittle damage characteristics.The mortar joints in the masonry significantly changed the damage pattern of the specimens.The peak loads of the masonry specimens with mortar joints were significantly lower than those of the individual block specimens.Comparing the two types of fibers in mortar,it was found that polyvinyl alcohol(PVA)fibers were more effective in enhancing the ductility of individual block specimens.Polyethylene(PE)fibers were more effective in enhancing the ductility of the masonry specimens with mortar joints.(2)Increasing the number of basalt mesh layers can significantly increase the peak load of the specimen,but with the increase of the number of mesh layers,the bond properties between the basalt fiber mesh and the cementitious material decreases,and the exploitation ratio of textile strength decreases.The optimum value of the bonding length of the composite layer exists.For the case of the bonding width of the composite layer of 50 mm,the bonding effect of the test specimen is the best when the bonding length is 150 mm,and the peak load of the specimen is the largest.When the bonding length is less than 150 mm,the bonding performance of the composite layer increases with the increase of the bonding length.For single block specimens,the bonding properties decreases when the bonding length continues to increase.(3)By summarizing the experimental data and modifying the coefficients of the existing exponential model,an bond-slip principal structure model suitable for the BFRP-FRCM composite layer reinforced masonry structure in this test was obtained,and the obtained loaddeformation curves fit well with the experimental results.The modified principal structure model can accurately simulate the test results with less error,which can provide reference for the next parameter analysis.