Experimental Study On Mass HPC Temperature And Stress Control

With the development of economy, the mass concrete is used more and more extensively. At the same time, temperature crack control of mass concrete is becoming the highlight and difficulty during the mass concrete construction.To get the Analysis Function of unstable temperature field under definite conditions, transform the heat conduct function through Variation Principles. Then solve the unstable temperature field by finite Element Method in space zone and Finite differential method in time zone, thus get the mass concrete temperature of different position and different time. Then start from Hook Theorem, reached the thermal stress of mass concrete. At the same time, transformed the shrink deformations during concrete harden process and the deformations reduce leaded by limited foundation rigid to equivalent temperature variation. At last consider the creep influence and get the compound thermal stress expression. Also edit computer program to solve temperature field and stress with Matlab.Under the guidance of above theory, the paper aimed at the characteristic that admixture and aruhuesiru are needed during modern HPC mixing. Through hydration heat test, systemically studied the character of heat output of cement admixed with fly ash, expansion admixture and water reducer separately or compositely. Analyzed the influence of them on temperature rise, heat output curve and heat output velocity in detail. Then fit heat output curve by exponential function and hyperbolic function, and solved heat output coefficient of different composition ratio cement.Contrast tested temperature of the project with the program calculations. The result showed that the program is practical.