Concrete Crack Control And Construction Technology Research And Engineering Applications

During the construction of the reinforced concrete structures, cracks may be caused by various, such as the temperature stress introduced by hydrated heat, the shrink shred, hypo-stress introduced by unequally sedimentation of foundation, the structural stress caused by loads.This paper review the works completed on the study of temperature stress and cracks during the construction of the reinforced concrete structures, at the same time put forward some problems to be investigated in the future. The paper systemically presents the shape, position, amount, emerging time and developing peculiarity of the crackle. and analyses the causes of cracks in the construction accordingly. After the improvement of the stress-computing model, the author finds an analytical solution for the temperature stress in the wall-slab of basement and the around-restricted floor. Accounting for other factors during the course of construction, the author finds the main reason of the cracks during the construction.Based on the reasons and peculiarities of cracks, the author suggests some control methods in design, materials and construction, such as avoidance of stress convergence in the design, increasing the steel bar for preventing cracks, reasonable usage of the addition and three-mixture technology, taking measure during the construction to reduce the temperature caused by hydrated heat and intensifying conserve. Regarding to the adverse factors caused by construction joint, the author suggests that construction joint be replaced by dilation joint.In the end, the author give his own reviews on the topic, and point out the several parts to be investigated later.The achievements acquired in the paper can be used in the following areas: assisting in establishing the construction scheme; decreasing the chance of cracking; avoiding the expanding join and construction joint, realizing the continuous construction of concrete; shortening the construction time limit for the project; controlling the engineering cost at the guarantee of engineering quality.