Capacity models for shear strength of exterior joints in RC frames: experimental assessment and recalibration

Several theoretical models are currently available in the scientific literature for evaluating the shear capacity of both exterior and interior beam-to-column joints in reinforced concrete (RC) frames. A reasonably wide set of those models, based on either analytical or empirical formulations, has been summarised within a companion work. The present paper firstly presents a wide database which collects results obtained in about two-hundred experimental tests carried out on RC joints. Those results are employed for assessing the above mentioned capacity models by considering a set of experimental data much wider than those usually utilised in the original formulation of such models. Accuracy and reliability of the various models are measured by quantifying some statistical parameters actually describing the relationship between the experimental evidence and the prediction of the various capacity models under consideration. Three relevant classes of joints (namely unreinforced, under reinforced and code-compliant) are considered with the aim of emphasising that the various models perform in a rather different way when applied to those different classes. Finally, a possible recalibration of the various models is proposed with the objective of enhancing their predictive capacity with respect to both the database as a whole and the three classes of RC joints mentioned above.