Study On Long-term Deformation Stability Of Steel Fiber Reinforced Self-stressing Concrete

As a new composite material, the steel fiber reinforced self-stressingconcrete effectively ameliorates the defect of reinforced concrete as lowtensile strength by the method of adding steel fiber into the concrete.The combined action effected by rebar and steel fiber can restrict theformation of self-stressing concrete, enhance the strength and thecrack-resistance effect of concrete, and it has been widely used inengineering applications.Now the theoretical research on self-stressing concrete and fibercomposite materials at home and abroad has become basically mature, butthe researches on self-stressing concrete and concrete materials withsteel fiber were generally focused on their mechanical properties, theresearches on their long-term deformation or long-term stability wererelatively rare. Due to the deformation is an important indicator oflong-term stability of concrete structures, this paper made a study onthe stability of SFRSSC long-term deformation, and made an analysis andsummary on long-term deformation, self-stress value and the prestressloss during long-term deformation process.Financial support of the work reported in this paper, by ScientificForefront and Interdisciplinary Innovation Project of Jilin University(Grant No.200903204), is gratefully acknowledged，the main research worksare as follows:1. Analyzing the deformation law of SFRSSC short-term limit expansionaccording to short-term SFRSSC deformation experiments, and thedeformation rules of self-stressing concrete with this complex ratio werealso analyzed on the basis of existing stress-strain formula and themicroscopic theory of self-stressing concrete.2. According to the deformation under long-term SFRSSC experiments,the author analyzed the effect on long-term deformation of concrete caused by different ratio of reinforcement, dosage of steel fiber and steel fibertype in the process of long-term deformation. The author also providedthe theoretical basis for the analysis on stability of long-termdeformation by analyzing the influence of shrinkage and creep effects.3. According to the experimental data from long-term deformation ofsteel fiber reinforced self-stress concrete, the author try to use thetheory of shrinkage and creep to qualitatively analyze the calculationmethod on prestress loss caused by the self-stressing concretereinforcement and steel fiber in long-term deformation process.