Study On Preparation And Basic Properties Of Coral Aggregate Concrete

In response to the call of the “National Island Reef Construction”,which was mentioned by General Secretary Xi Jinping in the report of the 19th National Congress,the construction of the South Island Reef is an urgent task.The island reef is far from inland and lacks building materials.Therefore,it is of great significance to use the island reef and the coral debris scattered around it to serve as aggregate material for the rapid and comprehensive construction of the island reef.In this paper,three strength grade coral aggregate concretes of C25,C30 and C40 were prepared and their basic properties were studied.The main contents are as follows:(1)crushing and mixing the undisturbed corals to obtain coarse and fine aggregates with good grades;analyzing the mineral composition of coral aggregates by thermogravimetric differential thermal and X-ray diffraction,and observing the microscopic morphology by scanning electron microscopy.And tested its basic physical indicators.(2)Taking the water-to-water ratio,the ratio of rubber to bone,the replacement rate of fly ash and the pre-humidity of aggregate as the indicators,the four-factor four-level orthogonal test of coral aggregate concrete was carried out,and the results were further optimized to determine the concrete.The mix ratios were C25,C30 and C40 coral aggregate concrete.(3)The compressive strength,axial compressive strength,splitting tensile strength,flexural strength and elastic modulus of three strength grade coral aggregate concrete cubes were tested to obtain the general mechanical properties of coral aggregate concrete.Regularity and comparison with ordinary concrete and general lightweight aggregate concrete.(4)Through the uniaxial compression test,the constitutive relations of C25,C30 and C40 coral aggregate concrete were studied,and the stress-strain curve was fitted in sections by the constitutive equation proposed by Zhenhai,and the coral bone was established.Constitutive model of concrete.(5)Through the analysis method of hardened concrete pore structure,the pore structure parameters of seawater mixed coral aggregate concrete were tested,and the chloride ion permeability of coral aggregate concrete was analyzed by electric flux method,and then the permeability of coral aggregate concrete was analyzed.Conduct an evaluation.