Experimental Investigations on Structural Behaviour of Reusable Interlocking Steel column base Connection with Demountability

Implementing a circular economy in construction is one of the potential approaches to limit the natural resource consumption by the construction industry and construction waste generation after demolition. There exist necessities for constructing buildings with easier demountability and direct reusability. One of the key aspects of reuse is designing with structural connections for demountability after service life, rendering the buildings for reuse. Therefore, this study endeavours to develop a directly reusable interlocking hold-down type column base connection for steel structures through full-scale experimental and theoretical investigations. The new reusable column base connection consists of a connector plate to replace the anchor rods in the traditional exposed column base connections to connect the concrete footing with the steel column and base plate assembly. This paper investigates the structural behaviour of the new reusable column base connection subjected to monotonic lateral loading and determines the effective embedment depth required for the connector to avoid concrete failure. A loading protocol that signifies reuse through repeated loading sequences is adopted for this study. Thus, each specimen is loaded for three repeated reuse cycles. A theoretical method based on the traditional component model concept representing the connection components as a combination of spring assembly is developed to predict the initial elastic stiffness of the connection. This will consequently aid in estimating the lateral displacement occurring for the corresponding design load. The theoretically predicted stiffness values are in good correlation with the experimental results. The design example for stiffness calculation is also provided for industrial practical applicability.