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

Abstract

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.

Finite Element Analysis of Reinforced Concrete Beam-Column Connections with Governing Joint Shear Failure Mode

“…A series of researchers have collected the test results in literature and have developed empirical and analytical relations to predict the RC joint shear capacity (Pauletta et al (2015), Muhsen andUmemura (2011), Park and, Lima et al (2012), Wong and Kuang (2014), Wang et al (2012), Jeon et al (2014) and Kassem (2016)). For example Kim and Lafave (2007) collected experimental results of semi-static cyclic tests carried out by different researchers on various types of RC beam-column connections (exterior, interior and corner joints).…”

“…The basic assumption of their model was that the load transferred from the linear elements to the joint is mainly resisted by a diagonal strut mechanism. In a state of the art article, Lima et al (2012) reviewed some of the analytical and empirical models introduced in the last two decades for predicting shear strength of RC beam-column joints. Some simplified models are also developed for simulation of the joint shear behavior in nonlinear static and dynamic analysis of RC frames (Sharma et al (2011), Favvata et al (2008 and Shayanfar et al (2016)).…”

Capacity models for shear strength of exterior joints in RC frames: state-of-the-art and synoptic examination

“…The comments reported herein represent a preliminary exam of the models considered in this study whose predictive capacity is thoroughly assessed in a companion paper (Lima et al 2012) aimed at measuring their accuracy and reliability on the basis of a wide number of experimental results collected from the scientific literature.…”

“…They have been presented in chronological order for emphasising the progressive evolution of knowledge about shear strength of RC joints and the general growing complexity of the analytical expressions proposed by various authors in the last two decades. The predictive capacity of those models is thoroughly assessed in a companion paper (Lima et al 2012) against a huge number of experimental results. However, this section proposes a synoptic comparison of the analytical expressions of the models under consideration with the aim of pointing out preliminary comments on them.…”

“…The models outlined and discussed in this paper will be assessed and compared in a companion work (Lima et al 2012) which collects a wide database of experimental results of tests on exterior beam-to-column joints. Thus, a complete evaluation of the relevant error and dispersion factors of those models will be presented therein.…”