Study On The Limitation Expansion Mechanism Of Self-stressing Concrete Under Steel Bars And Steel Fibers

The general self-stressing concrete is the low-stress in applications, At same time, it is apt to produce non-uniform limit expansion, and then call forth cracking of concrete along the reinforcement direction。Steel Fibers Reinforced Self-stressing Concrete as a new type of fiber reinforced composite material, makes good use of collective restraint of reinforcements and steel fibers to produce three-way self-stress for self-stressing concrete, which largely enhances crack resistance and tensile property of concrete, increases compaction of concrete and avoid cracking of reinforced self-stressing concrete. The interaction of reinforcements, steel fibers and self-stressing concrete, may exploit separate advantages to the full and raise mechanical properties of composite material, such as crack resistance, bending resistance and tensile property, etc.Currently, the expansion mechanism of self-stressing concrete has formed a relatively complete theory。The researches on self-stressing concrete and steel fibers concrete mainly concentrate on mechanical properties of material and load-bearing capacities of structures.The analysis on the microscopic mechanism of self-stressing concrete reinforced working together is deficient。.The work reported in this paper is supported by Scientific Forefront and Interdisciplinary Innovation Project of Jilin University (Grant No.200903204)the analysis on the microscopic mechanism of steel fiber reinforced self-stressing concrete is not relevant literature。the adding of steel fiber to reinforced concrete make the hybrid and complex effects of steel bars, steel fibers and self-stressing concrete the deformation characteristics is the important feature of SFRSSC, As the key problems during the designing of SFRSSC is how to determine the relationship between the deformation and since stress.The work in the paper concentrates on the interaction with limitation and concrete age, among steel bars, steel fibers and self-stressing concrete matrixThe major work has been done as follows:1. Analysing the corelation between confined deformation and age of self-stressing concrete under the restraint of reinforcements and clarifying its microscopic mechanism. On the basis of compatibility of reinforcements and self-stressing concrete, establishing the formula of reinforcement ratios and self-stress values.2. On the strength of confine test, analysing the corelation between confined deformation and age of self-stressing concrete under the restraint of steel fibers and steel fibers'type's impact unpon confined deformation, and clarifying its microscopic mechanism. On the basis of bondability of steel fibers and self-stressing concrete, establishing the formula of the content's characteristic parameter,deformation and self-stress values.3. Considering synthetically the interaction of reinforcements, steel fibers and self-stressing concrete, on the basis of compatibility, establishing the calculating formula of self-stress of self-stressing concrete under the combined action of reinforcements and steel fibers.