Research Of Environmental Temperature Effect On Large Area Of Concrete Plant Floor

With the rapid development of manufacturing industry, the construction scale of the plant is expanded constantly. An important study on large area of concrete plant floor is how to deal with the concrete structure crack caused by environmental temperature effect and concrete shrinkage. Especially in the north cold area, it is very important for the project whose construction cycle needs to go through a heating period before the use of concrete structure. Based on a practical project, this paper studies the environmental temperature effect on large area of concrete floor by the theoretical analysis and finite element calculation.Based on available theories and engineering practice, this paper considers factors such as environmental temperature variations, concrete shrinkage and creep, and so on, in analyzing environment temperature effect on concrete structure. The study fixes on the most adverse temperature difference, which includes the whole environmental temperature variations and equivalent difference in temperature by concrete shrinkage, and calculates the temperature stress respectively under the most adverse temperature difference by theoretical formulas and the finite element software ABAQUS. The result indicates there is no significant difference between the two methods.According to the practical projects, this paper makes linear elastic analysis by establishing finite element models, on the assumption that the concrete is homogeneous and continuous material, differential settlement does not occur in the foundation, and concrete elasticity module does not change with the time. The restraint of concrete slab is mainly from the action of friction between concrete slab and the foundation below. The result got from finite element analysis is that the maximum stress in the concrete floor is located in the middle of concrete slab, and the stress decreases gradually from middle to the end. It conforms to the concrete crack occured in the middle of concrete slab in this project after the concrete slab was cut with dummy joint. Furthermore, it indicates that the cutting size of concrete slab with dummy joint was not reasonable during the construction. Concrete cracking occured while temperature stress exceeded the tensile strength of concrete after the concrete slab was cut. The temperature stresses of different size concrete slabs are calculated respectively under the same restrictions and loading conditions. By contrast, the reasonable cutting size of the concrete slab with dummy joint is6mx4.5m. Finally, by changing the factors such as the concrete slab’s length, thickness, concrete strength, and so on, the rules and effect of these factors on temperature stress of the concrete slab are analyzed.