Experimental Study On Bearing Capacity Of High Durability Concrete Members With Corrosion Resistant Steel Bars

To create a suitable living environment for the residents by carrying out infrastructure construction in the South China Sea is not only an urgent need to ensure the production of reefs,people’s life as well as the development of marine,but also a major strategic need to maintain national security.High durability concrete is a combination of composite admixture concrete and hybrid fiber concrete.It has excellent resistance to chloride erosion and good mechanical properties,and the corrosion resistant steel bars have good corrosion resistance.Therefore,the application of corrosion resistant steel bars in high durability concrete can not only guarantee the bearing capacity of the members,but also improve the durability of the structure.Based on domestic and foreign research status and research results,Fiberglass reinforced bars(GFRP bars)and epoxy resin coated steel bars are selected as corrosion resistant bars,and high durability concrete with mixed fibers such as polypropylene fiber and basalt fiber is added.This paper studies the bond properties between corrosion resistant steel bars and high durability concrete,then carries out the test study on the bearing capacity of high durability concrete beams and columns,and finally establishes the revised formula for calculating the bearing capacity of high durability concrete members.The main research contents are as follows:1.The bond performance test of 18 high durability concrete specimens with corrosion resistant steel bars was carried out,and compared with the bonding properties of ordinary reinforced concrete specimens.The research shows that compared with ordinary concrete specimens,the bond strength of ordinary reinforced high durability concrete specimens increased by 20.75%,the bond strength of epoxy coated reinforced high durability concrete specimens did not increase significantly,and the bond strength of GFRP reinforced high durability concrete specimens decreased by15.37%;A modified formula for calculating the bond strength of concrete with high durability of common steel bar and GFRP bar is presented.2.The normal section bending test of 4 high durability concrete beams with corrosion resistant bars was completed,and compared with ordinary reinforced concrete beams,The results show that the crack spacing of high durability concrete beam specimen becomes smaller and the number increases;The epoxy-coated reinforced concrete beam with high durability have similar failure morphology,stiffness and mechanical properties as ordinary reinforced concrete beam,and the bearing capacity is increased by 13.2%.GFRP reinforced high durability concrete beam and ordinary reinforced concrete beams have little difference in bearing capacity.3.The compression test of 5 concrete columns with high durability of corrosion resistant steel bars was carried out,and compared with ordinary reinforced concrete column,The results show that the concrete column with high durability of epoxy coated steel bar have obvious omen before failure,good longitudinal deformation ability and good load holding capacity after failure.GFRP reinforced concrete column with high durability have no obvious signs before failure,and their deformation capacity is poor;The ultimate load of these two kinds of high durability concrete axial compression columns is about 10% higher than that of ordinary reinforced concrete column.4.The formula of bearing capacity of ordinary concrete members can be used to calculate the bearing capacity of high durability concrete beams and columns,and the result is on the side of safety.On this basis,the revised formula of bearing capacity of epoxy-coated steel reinforced high durability concrete members is put forward.Through the research work of this paper,the relevant test data of corrosion resistant reinforcement material and high durability concrete are enriched,and the theoretical basis and technical support are provided for the application of corrosion resistant reinforcement material high durability concrete structure in the South China Sea islands and reefs.