Experimental Study On Cracks Of Prestressed Steel Reinforced Concrete Members

Prestressed steel reinforced concrete (PSRC) is a bran-new structural style, which owns the excellent characteristics of large load resistance, fine stiffness, and good earthquake resistance as well as the steel reinforced concrete (SRC). Based upon the project practice and the experimental research, it indicates that the crack resistance of the SRC structure is not better than the reinforced concrete structure (RC), for its bonding between the rolled-steel section and the concrete is worse than the RC. Differently, the prestressing in PSRC will improve the performance of the crack resistance at some extent,so it will be of high significance to master the mechanism of cracks.This dissertation is a research about the PRSC members which bear the moment load and the axial tension. Through the investigation of the differences between various kinds of tension steel, thickness of the covering laver of structural steel, stirrup spacing, and the degree of prestressing force, this dissertation analyzed the result of the PSRC member trial and compared it with the result of the SRC member trial.Hypothetical tensile stress can intuitively reflect its relationship between crack width. Based on the elastic theory, hypothetical tensile stress was analysis and calculated, then a summarization was gave out among the hypothetical tensile stress, crack width and the basic parameters.Besides, based on the controlling theory of anti-crack, this dissertation took the rolled-steel section and the tension web plate as the tension steel when considering the effect of adhesive strength between the rolled-steel section and the concrete. As for the member in bending, with the consideration of the influences the prestressed steel in the different position would make on the width of the crack, this dissertation analyzed and deduced the calculational method of anti-crack of the PSRC in term of the analytic method of anti-crack of the reinforced concrete (RC). In the end, it put forward the expressions of the space length between the cracks and the width of the crack, and compared the expressions with the experimental results...