COMPARISON of TRUSS MODELS for SHEAR of REINFORCED CONCRETE BEAMS
It is generally agreed by concrete researchers that truss model theory provides a more promising way to treat shear. However, up to the present there is still no consensus regarding which version of truss model best represents the shear mechanism. The purpose of this study is to know the differences between truss model proposed by Nielsen et al, Collins et al, Hardjasaputra and Reineck for shear strength calculation. The truss model will be compared with shear formulation given in SNI 03-2847, AS 3600 and Eurocode2 and with experimental data available in the literature and also with the results of load test. The study shows that the four models are only applicable for certain amount of shear reinforcement (qv). Reineck’s truss model is valid for beams with qv≤qvmin, Hardjasaputra and Collins et al is applicable for beams with qv≥qvmin, whereas Nielsen’s truss model is valid for beams with qv=qvmax. This happened because shear failure mode changes as the amount of shear reinforcement changes. The study also shows that Collin’s truss model is the closest to the shear test results obtained from the literature, whereas from the load test the three truss models (excluding Nielsen) predict only ±60% of the ultimate load of the beams. This prediction is lower than the prediction based on the three codes.