Study On The Mechanical Performance Of High-strength Corrosion-resistant Steel-Coral Concrete Composite Beams

With the increasing demand for the development and utilization of marine resources and the implementation of China’s "Belt and Road" strategy,the construction of various marine engineering facilities has developed rapidly.However,the traditional concrete structure can not achieve local materials,and can not adapt well to the corrosive marine environment.There are problems such as increased transportation costs and poor structural durability.As a marine geological material,coral concrete solves the problem of shortage of building materials for islands and sea reefs,but its shortcomings such as high chloride content,high brittleness,and low ultimate deformation capacity limit the application of coral concrete in marine engineering facilities.Therefore,it is imminent to develop a high-performance composite structure suitable for coral concrete.At present,more research on coral concrete stays at the material modification level,and this article innovatively combines high-strength corrosion-resistant steel and coral concrete efficiently to explore and develop a high-performance composite beam structure suitable for marine environments.It can not only reduce transportation costs,but also resist marine corrosion environment and improve the durability of the structure.It is of great significance for promoting the development of marine engineering in China.In this paper,experimental research,theoretical analysis,finite element simulation and other methods are used to systematically study the mechanical properties of high-strength corrosion-resistant steel-coral concrete composite beams,aiming to explore the unique working characteristics of this new composite beam.The main research contents and conclusions are as follows:1.By conducting two-point static loading tests on high-strength corrosion-resistant steel-coral concrete composite beam specimens with different transverse reinforcement ratios,the failure mode and crack development trend of each specimen were studied,and the bearing capacity and ductility of each specimen were analysed in detail.The results showed that the composite beams in this paper had higher bearing capacity,better plastic deformation capacity,slightly lower ductility than ordinary steel-concrete composite beams,but better than coral concrete beams.The transverse reinforcement ratio had a direct effect on the failure mode of high-strength corrosion-resistant steel-coral concrete composite beams.2.Based on simplified plasticity theory,a correction coefficient η was proposed,and a formula for calculating the ultimate bearing capacity of a high-strength corrosion-resistant steel-coral concrete composite beam was given.Based on the reduced stiffness method considering bond slip,a formula for calculating the deflection of a high-strength corrosion-resistant steel-coral concrete composite beam was given.3.The finite element models of high-strength corrosion-resistant steel coral concrete composite beam were established by using ABAQUS.The rationality and effectiveness of the finite element simulation method were verified by comparing with the test results.On this basis,a further parameter analysis of the influencing factors of the composite beam’s mechanical performance was carried out.The analysis results showed that the ultimate bearing capacity of composite beams increased with the increase of coral concrete strength,steel content and shear connection.This studies showed that high-strength corrosion-resistant steel-coral concrete composite beams had better working performance,higher bearing capacity,and ductility can meet general engineering requirements.In addition,it used materials reasonably,could obtain considerable economic and social benefits,and had good development prospects in offshore engineering.