Experimental And Theoretical Study On Mechanical Property Of Concrete Cylinder Confined By HFRP

Fiber reinforced polymer (FRP) has been widely used in civil infrastructures due to their advantages in the light weight, high tensile strength, ease for construction. Because of bad deformation capacity of FRP, the ductility of structures confined by FRP is bad, which restricts its application. Hybrid fiber reinforced polymer (HFRP) is the way to resolve the problem, which can fully exert various fibers'advantage to optimize the mechanical property of FRP.Based on the experiment of concrete circular columns confined by HFRP under axial compression, this paper studies and analyzes the application of new fiber polymer, the mechanical property and stress-strain model of concrete circular columns confined by HFRP.Firstly, typical stress-strain models of concrete confined by FRP are summed up at home and abroad and the comparative analysis between experimental data collected and typical models is done. Besides, this paper analyzes the influential factors of stress-strain models, which provides substance to the theoretical analysisThis paper applies Basalt Fiber Reinforced Polymer (BFRP) and Polyethylene Fiber Reinforced Polymer (PEFRP) to strengthen concrete circular columns firstly and studies the mechanical property of concrete confined-columns and analyzes its feasibility. The results indicate that the cementations between resin matrix and BFRP, PEFRP are good; BFRP and PEFRP are good at ductility enhancing and low price, which are new FRP materials.Based on the experiment of concrete circular columns confined by HFRP under axial compression, this paper is emphasized on analyzing failure configuration, bearing capacity, stress-strain curve, deformation capacity and reasonable matching of HFRP. The HFRP consist in CFRP, AFRP, GFRP, PEFRP and BFRP.The existing stress-strain models of confined concrete are based on FRP, which are not good for HFRP. Based on experimental data, strength model and stress-strain model of concrete circular columns confined by HFRP are presented by regression analysis method. Regression models are in good agreement with experimental data, which can be used for engineers in the design of concrete confined by HFRP. This paper builds analysis model of stress-strain curve from the changing law of confine concrete'volumetric strain and secant modulus of HFRP-confined concrete. This model definite the physical significance of turning point and agree well with the experimental data, which can be applied to the concrete confined with HFRP and FRP.