Experimental Study On The Bond Of Epoxy-Coated Reinforcement To Seawater Coral Concrete

The seawater sea sand coral concrete(SSSCC)is developed by replacing all the coarse aggregates in the concrete with the corals and treating the sea sand as fine aggregate,the sea water as the mixing water.SSSCC has many advantages such as available local materials and the reduced project cost and construction period.However,it can cause serious mechanical and durability problems when the SSSCC is used in the island building structure.To avoid these problems,the epoxy-coated reinforcement(ECR)is adopted in this paper,and it is capable of effectively improving the ductility and dissipation capacity of the coral concrete structure.Furthermore,ECR also has many advantages,such as good corrosion resistance and low cost.However,there are few studies in this research field.So,this paper investigates the bond of SSSCC to ECR by experiment and theoretical analyses.The main studies are listed as follows.(1)The research status of bond of reinforcement to seawater concrete,sea sand concrete,coral concrete,and ordinary concrete are summarized,the central pull-out test of SSSCC reinforced with ECR is undertaken,and the effects of variables on the bond of SSSCC to RCR is analyzed.(2)The effects of the concrete type(ordinary concrete,SSSCC),strength(C25,C35),rebar anchorage length(3d,5d,8d),rebar type(ordinary rebar,epoxy-coated rebar)and cover thickness(67mm,42mm)on the bond-slip properties of SSSCC to ESR are investigated,and the failure mode and bond strength of SSSCC reinforced with ECR under different factors are analyzed.(3)The bond stress distribution tests of SSSCC reinforced with ECR under different concrete strength and anchorage lengths were carried out.The distributions of bond stress along the bond length under different tensile loads are studied.(4)The long-term bond-slip properties of SSSCC to ECR are experimental investigated.The central pull-out test technique is adopted.The effects of curing condition(outdoor exposure,seawater immersion,simulated wave tide)and age(28 days,1 year)on the bond properties of SSSCC to ESR are investigated,and the changes of failure mode and bond strength under different effect factors are analyzed.(5)The bond-slip constitutive model for the SSSCC reinforced with ECR is established based on the test results and existing models.The analytical expression of bond strength of SSCC reinforced with ECR is established based on the test results and the fitting analyses.