Experimental Studies of Reinforced Concrete Beams Using Embedded Steel Trusses

摘要

The shear performance of reinforced concrete beams using embedded steel trusses was studied in this work through experimentation and theoretical research. Five beam specimens with small shear span-depth ratios were tested to investigate their structural performance and ultimate shear strength. Test results indicate that a steel angle truss adding horizontal reinforcement is the better composition method for an embedded steel truss to improve the shear performance of a concrete beam. Compared with the common reinforced concrete beams, the ultimate shear strength, elastic deflection stiffness, and elastoplastic deflection stiffness of reinforced concrete beams using steel angle truss adding horizontal reinforcement are increased by 80.398%, 93.280%, and 495.721%. respectively. The experimental results further demonstrate that embedding the steel trusses in reinforced concrete beams is indeed a promising new technique that can greatly improve the structural performance of reinforced concrete beams in shear failure. Based on the interior force equilibrium equations of the failure section of specimens and Mohr 's circle theory, aflexural-shear strength model is proposed in this paper for predicting the ultimate shear strength of reinforced concrete beams with embedded steel trusses. The proposed analysis model has a clearly defined mechanics meaning for the shear strength of composite steel truss and concrete beam under flexural-shear failure pattern, instead of using empirical formulas. The predicted calculation results are consistent with the test results. The maximum calculated relative error is less than 9% compared with test results.