Research On Mechanical Properties And Durability Of SiC Concrete

Adding different admixtures in concrete is an effective way to improve its performance,silicon carbide powder is photovoltaic industry in the cutting process as a traditional abrasive production of industrial waste,the main chemical composition is Si C,with high strength,corrosion resistance and other advantages,the application of it in concrete,not only can be recycled,but also can improve the performance of concrete.This thesis mainly includes the following research contents:(1)Black silicon carbide and green silicon carbide were mixed into concrete with different contents,and the compressive strength,splitting tensile strength and flexural strength of specimens at different ages were tested to study the influence of the change of silicon carbide grain size,type and dosage on the above properties.The research shows that the appropriate amount of incorporation of silicon carbide has improved the mechanical properties of concrete at each age,the grain size of 10μm silicon carbide has improved the mechanical properties of concrete more obviously,the compressive strength and tensile strength of green silicon carbide on concrete is higher than that of black silicon carbide,and the anti-bending strength of green silicon carbide is lower than that of black silicon carbide.With the increase of the dosage,each strength index of concrete presents a trend of first rising and then decreasing,and reaches the maximum value at 5% dosage.(2)The uniaxial compression test of green Si C concrete prisms with different admixtures was carried out.Through the processing and analysis of the test data,the stress-strain curves of Si C concrete with different admixtures were fitted,and the uniaxial compression constitutive relation model suitable for Si C concrete materials was obtained.Using this constitutive model,the finite element simulation of Si C concrete beam in pure bending state is carried out.The research shows that the bearing capacity of the simple supported Si C concrete beam with 5% content is the maximum,and the strain of the mid-span section along the axis of the beam varies linearly with the height of the section.(3)Based on the experimental data,the prediction model of compressive strength of SIC concrete based on BP neural network is established.The results show that the model can predict the compressive strength of concrete at the corresponding age according to the cement dosage,water-cement ratio,type of silicon carbide,particle size of silicon carbide,amount of silicon carbide and amount of silica fume.The predicted value of BP neural network is in good agreement with the experimental results.(4)Through the seawater erosion test of green Si C concrete with different dosage,the change rule of compressive strength,mass loss rate and water absorption rate of different dosage Si C concrete was studied.The results show that with the increase of the number of impregnation-drying cycles,the strength and mass loss rate of concrete increase first and then decrease,and the water absorption decreases first and then increases.Adding proper amount of silicon carbide into concrete can improve its seawater erosion resistance.