Experimental study on the seismic performance of RC frames considering the cast sequence of infilled walls and columns

Abstract

The relative values of lateral stiffness and ultimate limit state of bearing capacity of vertical members are defining factors of the seismic failure or collapse mode of structures. This paper focuses on how the different construction sequences of infilled walls and frame columns influence the seismic performance of frame structures based on the low-cycle reciprocating loading tests of six single-layer two-span frame structure models with a ratio of 1:4, including two frame models without infilled walls (F model), two frame models with walls built later (LW model), and two frame models with walls built first (FW model).According to the test results, different construction sequences of infilled walls have a significant impact on the seismic performance of frame structures. The FW model introduces the process of “building the wall first and then casting the column” with the wall and the column highly combined with each other and the infilled wall involved in the internal force distribution of the frame structure, boasting the largest bearing capacity and initial stiffness; LW model is built by “pouring the column first and then building the wall” with a low combination between wall and column, its bearing capacity and initial stiffness second to FW model; F model has the smallest bearing capacity and initial stiffness. Shear failure and poor ductility are found in the FW model due to the restraint effect of the infilled wall; bending failure in the F model with a large displacement but good ductility; shear failure tends to appear in the LW model structure with the failure in bonding between reinforcement and concrete in the end and good ductility. The research results can provide a reference for the elastic–plastic seismic response analysis considering the interaction of infilled wall and frame.