Experiment On The Tensile Properties Of Self-stressing Concrete Reinforced With Steel Fiber And Steel Bars

Steel fiber reinforced self-stressing concrete(SSRSSC)is a new type of high performance composite materials. Adding short-cut steel fibers into the self-stressing concrete, the self-stresses are created in concrete due to the restriction to expansion by steel fibers as well as steel bars. In addition, steel fiber could improve the cracking resistance and toughness of concrete. steel fiber’s randomly three-dimensional distribution in self-stressing concrete increase cracking load and and ductility of reinforced concrete members. Both steel fiber concrete and self-stressing concrete can do contributions to tensile strength.Steel fiber reinforced self-stressing concrete are applied in penstock and bridge reinforcement as a result of good structural performance. However, with the improvement of processing technology and production scale of steel fiber, the content used in structures is decreased from initial more than80kg/m3to less than80kg/m3,even to20kg/m3. therefore, for purpose of meeting the pratical requirement, the gap of the previous research have to been filled in. This paper investigates the tensile properties and the restricted expansive deformation of steel fiber reinforced self-stressing concrete in low content of steel fiber. Furthermore, it is specially noted in analysis of stress-stain full curve that the decompressing process is taken into consideration. Thus a complete tensile stress-strain curve of steel fiber reinforced self-stressing concrete is provided for structural analysis. The main contents of this paper are as follow.(1) The development of the restricted expansive deformation with ages is studied by measuring total24groups of prims specimens of steel fiber reinforced self-stressing concrete with different contents of steel fiber (20kg/m3-80kg/m3)and reinforcement ratios(2) the influence of content of steel fiber and reinforcement ratio on the restricted expansive deformation is discussed and the calculation of initial self-stresses is suggested.(3) the standard static tensile test of24group of specimens is carried out to obtain the load-displacement curves of steel fiber reinforced self-stressing concrete with steel bar. A series of stress-strain full cureve are induced combined with the initial stress of steel fiber reinforced self-stressing concrete, steel fiber reinforced self-stressing concrete in different steel fiber content and different reinforcement ratios.