The Concrete Adiabatic Test Based On Ansys Numerical Simulation

With concrete were used more widely in many kinds of engineering, more and more people pay attention to the durability of concrete. Heat was occurred in cement hydration produce, the temperature constantly rising. Due to non-load reasons just like temperature, at early age, the cracks were produced in concrete structure will affect the safety and durability of the structure. Also, the adiabatic temperature rise of concrete is an important indicator of temperature control, study adiabatic temperature rise has a very important significance for quantify thermal stress and assess the impact of concrete temperature crack. With research and exploration about concrete hydration heat, people found that the incorporation of fly ash in concrete, reducing the amount of cementitious material and using of large water-cement ratio of the mix were able to reduce the heat of hydration of concrete, improve the durability of concrete structures as well. Based on the adiabatic temperature rise, we using the finite element software doing the heat-solid coupled numerical simulation. Compared to the traditional method, we can not only get more precise temperature change process, but also can reduce the workload with high accuracy of the simulation results.This paper based on the adiabatic temperature rise experiment, studied the influence of adiabatic temperature rise performance within three factors, these factors were water-cement ratio, fly ash and into the mold temperature. After that, the test data obtained by regression analysis, proposed adiabatic temperature rise formula which contains three impact factors.Finally, by using the ANSYS finite element software, based on the experiments results,simulate the concrete structure temperature and stress field. The results of the test showed that:(1) Through the adiabatic temperature rise test within different water-cement ratio, fly ash and concrete into the mold temperature conditions, we get the adiabatic temperature rise and temperature changing process for the different mix of concrete. With the water-cement ratio increasing, the concrete cementitious materials hydration environment is relatively good,hydration exothermic process in advance. Fly ash replace the same amount of cement can reduce the adiabatic temperature rise of concrete effectively, delayed the exothermic peak.The concrete adiabatic temperature rise in seven day was affected little by the into the mold temperature, but it has significantly impact on early adiabatic temperature rise. With the into the mold temperature rising, cementitious materials hydration reaction rate is accelerated and the concrete temperature was rising as well.(2) Regression analysis of the data obtained in the adiabatic temperature rise test, then determine the relevant parameters. Deduced concrete adiabatic temperature rise calculation model consider water-cement ratio, fly ash and concrete temperature. By comparison with the measured data, it’s showed the accuracy of the formula. The concrete adiabatic temperature rise calculation model can be used to predict the process of concrete, it has some practical value for the actual project.(3) Through the ANSYS finite element analysis about concrete structure, we can get the temperature distribution and the stress distribution field of concrete construction. Temperature has large effects on the concrete structure, especially the large volume of concrete structure. It is difficult to exchange heat for the concrete structure block at the center with the outside, the accumulation of heat made the temperature rising, and then the structure expanded gradually and come with compressive stress, while the outer concrete along with tensile stress when the temperature decline. Therefore, mass concrete should take measures timely to cool down,avoid temperature changing quickly and come with temperature cracks.