Analytical investigations of seismic performance of different joint details for composite RCS frames

Composite RCS frames, comprising of Reinforced Concrete (RC) column and Steel (S) beam are gaining popularity as an attractive alternative to traditional steel moment frames for mid to high‐rise buildings as well as conventional RC construction for low‐rise buildings. The prime concerns with RCS frames are constructability and load transfer at beam‐column connections. Over the last 30 years, several joint details, viz. face bearing plates, erection steel columns, vertical joint reinforcement, and steel band plates have been proposed for RCS frames. The moment‐rotation behavior of these joints was established through quasi‐cyclic experimental programme. The moment‐rotation characteristics of RC column‐S steel beam joint significantly affect seismic performance of the overall frame. The objective of this paper is to evaluate the seismic performance of low and mid‐rise RCS moment resisting frames with different connection details, available in published literature. The nonlinear analyses of differently jointed RCS moment resisting frames is carried out and performance assessed in terms of collapse capacity and the available response reduction factor, R_avl. Seismic collapse risk of RCS frames is estimated to understand performance under uncertain ground motion.