Model Experiment On Crack Control Of Steel Reinforced Concrete Beams

Steel reinforced concrete (SRC) structure has high bearing capacity, stiffness, and good seismic performance, and thus is subjected to general concern in engineering. However, the existence of cracking in SRC structure has seriously hindered its wide application in engineering. In this thesis, model experiments are performed to study effects of setting shear studs on the steel flange and web to control crack on SRC beams, and to check applicability of calculation methods in China's current design codes of SRC structure. The primary topics of this thesis include the following parts:(1) Model experiments on static bending of SRC beams. 6 model specimens with 1/4 scale of SRC beams are designed and manufactured, and divided into two groups in accordance with or without shear studs. The bearing capacity and maximum crack width of model beams are checked according to the two China's current design codes of SRC structure. 2-points loading test on static bending of the model beams are carried out to study the cracking load, maximum crack width, curve between load and mid-span deflection, curve of load and strain at the flange of steel and the longitudinal reinforcement in the tensile part and crack distribution of the model beams.(2) Finite element analysis on static bending of SRC model beams. Applied ANSYS software, the simplified finite element models of the 2 groups of model beams with or without shear studs are established respectively to investigate the development and distribution of cracks and the cracking load of the model beams out the process of crack occurrence and got cracking load in the cases with or without shear studs.(3) Comparison of the model test results, the finite element analysis results and the calculation results according to the current design codes. the model test results, the finite element analysis results and the calculation results according to the current design codes of the two groups of SRC model beams are compared to analyze the effects of setting shear studs on the steel flange and web to control development and distribution of cracks on the SRC beams.The research shows that the set of shear studs on the steel flange and web has no significant impact on the flexural strength, deformation and cracking load of the SRC beams, but is able to effectively control the crack width where the maximum crack width is reduced to 50%. Finite element analysis is able to more accurately simulate the cracking process of the SRC beams, and the analysis results of cracking load are good agreement with the model test results. There is a big error in the calculation of the bending capacity, cracking load and maximum crack width of the SRC beams according to the two China's current design codes. Therefore, the China's current design codes should be revised and some revisions are suggested.