Shrinkage Stress Calculation And Research On Test Method Of Concrete Structure

The shrinkage cracking of concrete is an important problem in the academic circles and structure engineering.From the point of restraint for the shrinkage cracking,the experimental and theoretic studies are further conducted on the three basic factors ( the shrinkage strains of concrete,the mechanical properties of concrete,and the degree of restraint for concrete ) . So,the mechanism of the shrinkage cracking is deeply studied,and the effective control measures of the shrinkage cracking for concrete structure are supposed to reply the need of the engineering.Frist,several common calculation model of dry shrinkage and Self-shrinkage about concrete were introduced in the paper, and make comprehensive evaluation on these model from principle and applicable scope, combined with Micro-Structure Analysis of Concrete, the mechanical of concrete shrinkage and relationship between humidity field and macroscopic deformation are investigated.Second, considering the deformation of concrete structure component to measure, based on the principle of gaussian integral function, this paper puts forward the way of measuring the gaussian integral covers the deformation of the concrete structural components. The gaussian integral function is applied on concrete structural components to measure deformation, and calculate the variation of tensile strength as age change according to the definition of strain of concrete.Third, sufficient size component test and field test was conducted. The strain of sufficient size plain concrete and reinforced concrete was measured by the way of erecting batches and decorating measuring-point according to the gaussian integral, and the total value of regression analysis. The constraints along the concrete beam variation of different heights is given through through the cross-section regression of different experimental results along different heights. Then, the formula is given considering the reinforcement of the contraction. Through the plain concrete beams and reinforced concrete beam test value to verify that the reinforcement of the literature of the validity coefficient. At last, start with the theoretical analysis of concrete structures restraint stress. Wang Tie-meng proposed method which prove to be right and can be applied to practical engineering. Then, the crack on the basement floor is evaluated through calculating shrinkage stress of North Village New works basement floor. Meanwhile, Summarize advantages and disadvantages of sufficient size component test and field test and puts forward the improvement measure of concrete structure shrinkage test method.