Experimental Study On Performance Under Loads And Ductility Of Perstressed High-strength Concrete Beams

With the development of our country’s economy and the improvement of theconstruction process, the prestressed technology, the high strength reinforcement’sapplication technology and the high strength concrete components are more andmore applied to large span and high rise buildings. Its application has brought goodeconomic benefits and social benefits. For the prestressed components thatcombined with the high strength steel and high strength concrete, the forceperformance and the ductility maybe different with the common concretecomponents. So it is necessary to carry out the further experimental research.In order to study the flexural behavior of the prestressed high strength steeland high strength concrete beams,12beams are tested under two point symmetri-cal concentrated at tri-span. At the time of observe the whole process from crackingto lose the load-carrying capacity of the beams, record and analysis the steel strain,crack width, deflection and ductility. Based on the experiment, section analyses areproceeded through the Matlab. The curves of load-curvature are got from theanalysis results. Based on the comparison of the experiment load-curvature curvesand the analog load-curvature curves, curvature ductility is analysised. Through theCANNY analog analysis, load-deflection curves are got. Compared with theexperiment result, load-deflection curves are in good agreement. Use the CANNYanalog analysis, factors affecting the ductility of the parameters is analysised. Theresults prove that the ductility decreases with the increasement of the prestressingstrength ratio and the conversion reinforcement ratio, and the ductility increaseswith the increasement of concrete strength and the index of the compression steeland the volume stirrup ratio.