Research On Inclined Section Shear Capacity Of Reinforced Concrete Beams

Shear behavior of reinforced concrete beam is complex, including numerousinfluencing factors. Although lots of researches have been working on shear behavior ofbeams for years, there is not a perfect shear theory yet. Most shear formulas in currentcodes are semi-empirical or empirical, rather than clarify shear models, which limitstheir applicable scope. Therefore, it is necessary to do further research on the shearcapacity.Firstly, several theory models on the shear capacity of reinforced concrete beamsare reviewed and compared of the advantage and disadvantage, and the shear model ofChinese code, American code and European code was listed, from which it can be seenthat shear behavior is insufficiently understanded and the theory model is diversified athome and abroad. By contrast, truss model is widely used, which is the trend of thedevelopment of the shear theory.Secondly, the shear capacity calculation method ofreinforced concrete beams with stirrups of Chinese code (GB50010-2010), Americancode (ACI318-08) and the European code (EN1992-1-1:2004)were compared, andthe effects of the concrete strength, shear-span ratio, longitudinal reinforcement ratio forshear strength of these code was also studied. The effects of the concrete strength,shear-span ratio, longitudinal reinforcement ratio were also studied. According todomestic and international219experimental results of the shear capacity of simplysupported reinforced concrete beams under pointload, calculation and experimentalvalues of the standard shear capacity are compared and analyzed among Chinese code,American code and European code, and the minimum or maximum stirrup ratio werecomparatively analyzed. The results show that shear capacity for reinforced concrete beams of European code is the largest, Chinese code is middle, and American code isthe smallest, and the calculation of both Chinese code and American code is smallerthan the actual value, which is partial to be conservative. According to the aboveanalysis, the truss-arch model considering the arch-effects, soft phenomenon of concreteand others was proposed on shear capacity calculation. According to domestic andinternational102experimental results, calculation of new formula and experimentalvalues of the standard shear capacity are compared, and at the same time, it also made acomparison among new formula, Chinese code and American code. The results showthat the calculation of Chinese code and American code were low and conservativewhile the new proposed calculating results are better consistent with experimentalvalues, which can accurately reflect the shear capacity of reinforced concrete beams andits main influence factors.Finally, the shear method of Chinese code is discussed in thispaper, and shear calculation formulas of the shear capacity for concentrated load anduniform load was put forward, which can solve the problems existing in the Chinesecode, and also has important significance for guiding the calculation of inclined sectionshear bearing capacity for engineering structure.