Experimental Study On Axial Compressive Performance Of FRP-PVC Pipe-constrained Coral Aggregate Concrete Columns

Traditional concrete raw materials are scarce in marine island construction,and the use of coral aggregate concrete can not only reduce the high cost of concrete raw material transportation by using local materials,but also shorten the construction period and reduce construction costs.However,coral aggregate is loose and porous,and the strength of the prepared concrete is generally low,and the reinforcement in coral aggregate concrete is very easy to rust in the marine environment.The use of FRP-PVC pipes to restrain coral aggregate concrete can,on the one hand,improve the load-bearing capacity of the components and,on the other hand,isolate the concrete components from corrosion by harmful marine aggressive media.This paper focuses on the load-bearing performance of FRP-PVC pipe restrained coral aggregate concrete columns,and the specific research contents are as follows:(1)According to the limit equilibrium theory,the damage criterion of FRP-PVC pipe restrained coral aggregate concrete column is established,and the bearing capacity calculation model of FRP-PVC pipe restrained coral aggregate concrete column is established through theoretical derivation,and the model is verified based on the results of axial pressure test of the restrained column.(2)The FRP-PVC pipe restrained coral aggregate concrete column axial compression test was carried out to analyze the effects of different FRP types,FRP hoop spacing and axial compression ratio on the damage mode,ultimate bearing capacity and deformation of FRP-PVC pipe restrained coral aggregate concrete column based on the test results;FRP hoop coefficient was introduced to quantitatively analyze the effect of FRP restraint on PVC pipe coral aggregate concrete column The effect of FRP restraint on the load carrying capacity of coral aggregate concrete columns with PVC pipes is quantitatively analyzed.(3)Analyze the effects of different FRP types,hoop spacing and axial compression ratio on the variation pattern of axial compression stress-strain curve of FRP-PVC pipe restrained coral aggregate concrete column,and establish the stress-strain relationship model of FRP-PVC pipe restrained coral aggregate concrete column according to the test results of stress-strain curve of coral aggregate concrete column under different restraint effects.