Research And Application Of Crack Control Technology Of Ultra-large Area Concrete Ground

With the development of the city,the application of ultra-long large area concrete structure was more and more extensive,how to control the concrete cracks effectively in the case of less or none seaming had become the focus of scholars.This article research the mechanism of crack generation first,and the effect of high performance concrete in ultra-large area concrete ground cracks was studied,Then,the relationship between the temperature stress and the influence factors of the ultra-long large area concrete ground was analyzed numerically.At last,Analysis of construction control technology for ultra-large area concrete ground crack,and proposed crack control measures The main contents and conclusions are as follows:(1)The mechanism of concrete temperature deformation,shrinkage deformation and creep caused concrete cracking was analyzed theoretically,and the main influencing factors of these three kinds of cracks were introduced(2)The influence of three factors of steel fiber content,polypropylene content and polypropylene length ratio on the ultimate tensile strength of steel polypropylene fiber concrete had analyzed.Through the steel-polypropylene fiber concrete splitting tensile test,the optimum ratio of tensile strength of concrete was obtained.(3)Through the finite element ABAQUS,the influence of the restraint effect on the restraint stress of the ultra-large area concrete ground panel was analyzed,and the relationship between the maximum pouring length,the design value of concrete tensile strength and the interlayer friction coefficient had obtained.(4)In view of the influence of inter-layer constraint effect of ultra-large area concrete ground cracks,the application of asphalt-sand stress-absorbing layer in the control of ultra-large area concrete ground crack had put forward and Asphalt-sand optimum ratio test was carried out(5)Through theoretical research and numerical analysis,the construction control technology of ultra-large area concrete ground cracks was put forward and the application of the ultra-large area concrete ground project in the depot of the lao guan cun was carried out in the first project of wuhan metro line 6.