EXPERIMENTAL STUDY ON SHEAR CAPACITY OF PRESTRESSED I-STEEL ULTRAHIGH REINFORCED CONCRETE BEAMS
Based on a shear experiment of 12 prestressed I-steel ultrahigh reinforced concrete beams and 2 prestressed I-steel ordinary reinforced concrete simply supported beams,the main factors affecting the shear performance of a prestressed I-steel ultrahigh reinforced concrete beam were revealed and the influences of the shear span-depth ratio,the space of stirrups,the thickness of web,the compressive strength of concrete and the degree of prestress on the failure mode,the load-deflection curve,the first shear crack load and the shear capacity of test beams were investigated.The experimental results show that prestressed I-steel ultrahigh reinforced concrete beams have better shear capacity and shear ductility,as well as higher stiffness than those of prestressed I-steel ordinary reinforced concrete beams.In addition to the experimental results,a new method for predicting the shear capacity of prestressed I-steel ultrahigh reinforced concrete beams is proposed.The proposed method gives satisfactory predictions as compared to the experimental results.The research achievements are expected to provide a theoretical support for the design calculation and engineering application of prestressed I-steel ultrahigh reinforced concrete beams.