Experimental seismic analysis of new types of steel-reinforced lightweight concrete columns with cross-shaped steel section

Abstract

In structural engineering, lightweight concrete (LWC) and steel reinforced concrete (SRC) elements have shown many advantages. Three innovative new types of steel-reinforced lightweight aggregate high strength concrete (SRLWAHC) columns with cross-shaped steel sections subjected to constant axial compression and reversal cyclic loads are presented in this paper to explore the cyclic performance, including the failure mode, hysteresis characteristic, ductility, stiffness degradation, and energy dissipation capacity. The effects of the axial compression ratio (nc) and steel section configuration on the seismic performance of the new types of SRLWAHC columns are experimentally studied. The test results indicated that the tested specimens showed quite plump and stable hysteresis curves and better ductility and drift capacity, indicating the good seismic performance of the tested new type columns. The lateral load capacity, ductility, and drift capacity of the specimen with an X-shaped steel section were larger than the specimen with a +shaped steel section, and the lateral load capacity of the sample with a larger nc was larger than the specimen with a smaller nc. Five calculation models have been applied to predict the seismic capacity of the new type columns and to know the feasibility of applying the available traditional models and a modified model to the new type of columns. The theoretically calculated results using JGJ 138-16 model are averagely conservative and the closest to the experimental test results. The paper is finalized with recommendations for future studies.