Study On Oblique Section Shear-bearing Capacity Of RPC Beam Based On Softened Truss Theory

Reactive Powder Concrete (RPC) is a new kind of material of high strength and high flexibility. There is obvious difference between RPC and normal concrete for deformation under load and failure mode because of the difference on material property. Research on behavior of shear resistance of RPC beam could offer reference for its design method of shear resistance, thus the application of RPC beam can be extended.In this paper, the softened truss theory is applied to the study of diagonal shear strength of RPC beam. Based on softened truss theory, the softened constitutive relationship and material eigenvalue is introduced, with the property of RPC material considered. Theoretical assumption, threshold of failure mode, and factor data are modified and complemented. The whole process analysis method of shear strength after crack of RPC beam is built, which can solve the shear strength of member accurately.The whole process analysis method of shear strength of RPC beam is programmed by MATLAB. The 12 RPC beams of the field test referred are analyzed for shear resistance and failure model, with various factors of transverse reinforcement ratio, longitudinal reinforcement ratio, and shear-span ratio considered. Shear strength of those tested beams and another group of 10 prestressed RPC beams are calculated. The theoretical and experimental results are fit well so that the availability of the method proposed in this paper is certified.With the softened truss model, the effect of influencing factors of concrete strength, shear-span ratio, transverse reinforcement ratio, longitudinal reinforcement ratio, and prestress to shear strength of RPC beam are analyzed with the softened truss method and its program. The influence law of each factor is analyzed.Compared with computing formulas of shear strength from various standards, and combined with experiment analysis and parameter analysis, the influence of parameters to shear strength is concluded and a formula of calculating shear strength of RPC beam is suggested. The formula is certified with field tests that it can be referred to shear resistance design and engineering application of RPC beam.