Study On Steel Lined Steel Fiber Reinforced Self-Stressing Concrete Penstock

Steel fiber reinforced self-stressing concrete is a new type of fiber reinforced composite. The self-stress induced by steel bars as well as steel fibers and enhancement of steel fiber could increase tensile strength of concrete and improve the ductility, fatigue strength, impacting strength and impermeability of concrete. At present, the research on steel fiber reinforced self-stressing concrete mainly concentrates on reinforced mechanism and mechanical properties. However, there is no literature on structural properties of steel fiber reinforced self-stressing concrete and applications. In order to increase the first-crack strength of steel lined reinforced concrete penstock, which is a new type of hydro-structure, steel fiber reinforced self-stressing concrete could be applied. In this paper the author presents the research work on steel lined steel fiber reinforced self-stressing concrete penstock. The major work has been done as follows:1. Experiments on uniaxial direct tensile are carried out to obtain tensile strength of self-stressing concrete with steel fibers reinforcement as well as steel bar in this paper. Parameters of experiments include three self-stressing grades, three contents of steel fiber and four reinforcing steel ratios. It is concluded that tensile strength of self-stressing concrete restrained by both steel fibers and reinforced steel bars is significantly increased. Formulas are suggested by statistic analysis.2. Experimental study on tension stress-strain full of steel fiber reinforced self-stressing concrete was carried out. According to the test results, some eigenvalues on the curves are given, such as tension strength, elastic modulus. The influence of grade of self-stress, steel fiber content on these eigenvalues is discussed. From a practical view of point, curve equations for finite element analysis are proposed.3. Based on the measure results of expansive deformation of a series of self-stressing concrete prism specimens with various ratio of reinforcement as well as steel fiber volume fraction from 1day to 28 days, the relation between the expansive deformation and the age were analyzed. In addition, an exponential equation on reinforcing ratio and expansive deformation was proposed by statistical analysis.4. Limited reinforcing ratio of steel fiber reinforced self-stressing concrete member in tension was presented. From two aspects minimum reinforcement ratio was derived. According to test results upper limit of ratio of reinforcement (optimum reinforcing ratio) was proposed.5. In this paper, according to the theory of elastic mechanics, a series of method...