Effect of different types of aggregates on the performance of concrete-filled steel tubular stub columns

This paper presents a series of tests on concrete-filled steel tubular (CFST) stub columns under axial compression. Five different concrete mixes with the same cement content and water/cement ratio were designed using normal limestone aggregate, lightweight aggregate, steel slag, and waste glass. The influence of aggregate type on the failure modes, development of axial and lateral strains, strength and ductility of CFST stub columns is discussed. The experimental results demonstrate the feasibility of using steel slag and/or waste glass to replace partial or all concrete aggregates; the novel composite columns have similar and in some cases even better structural behaviour compared with normal CFST columns. The test results are compared with predictions of Eurocode 4 and finite element analysis, and the agreement between them is reasonable.