Study on Temperature Effect of Concrete Mechanical Properties

Taking Plain Concrete column and Reinforced Concrete column for research objects, the uniaxial compression experiments were carried out to fix baking time, change temperature and fix temperature, change baking time. Numerical simulation was performed using FLAC3D software and all experimental data were collected for analysis. In the same baking time, the higher the temperature, the smaller the elasticity modulus of theplain concrete column and reinforced concrete column, the peak strength decreased gradually and the peak strain increased gradually; the residual strength of plain concrete column decreased, and the residual strength of reinforced concrete column increased gradually. With the temperature increasing, the dehydration shrinkage of cement paste and the thermal expansion of aggregate lead to the increase of micro cracks in the interface, which weakens the strength of concrete. At the same baking temperature, with the increase of baking time, the peak strength of plain concrete column and reinforced concrete column increased first and then decreased, and the residual strength was smaller. With the bound water out of cement gel, the cementing effect of cement particles was enhanced, eased the stress concentration on the seam, which is conducive to improve the concrete strength. The elastic modulus of plain concrete column decreased gradually. the elastic modulus of reinforced concrete column increase gradually; the peak strain of the plain concrete column is gradually increasing, the peak strain of the reinforced concrete column decreases. Because the concrete expansion coefficient is small, the concrete squeeze steel bar, the bond strength between steel and concrete is improved.