Experimental study on demountable steel-concrete connectors subjected to combined shear and tension

Abstract

Composite beams are being used increasingly in construction due to their benefits over beams consisting of the steel component alone. In some applications such as in composite coupling beams and infill walls, steel-concrete connectors must resist uplift forces in addition to shear forces. Therefore, there is a need to carry out experimental testing to investigate the performance of steel-concrete connectors under combined loading. Furthermore, the separation of the steel and concrete components is a destructive activity and requires remelting of the steel component if it is to be reused. Remelting requires energy that usually comes from unsustainable resources. Hence, research has been carried out in this paper on demountable steel-concrete connectors as they allow demounting and easy separation of the steel and concrete components and reuse.The performance of three types of steel-concrete connectors subjected to combined shear and tensile loading was investigated experimentally. A pull-out test was carried out to determine the tensile resistance of each type of steel-concrete connector. This was followed by a series of modified push tests to determine the interaction between shear and tension loading. Tensile resistance which had been determined from pull-out tests was applied in increments of 25% to each group followed by shear loading until failure of the steel-concrete connector was observed.Based on the experimental investigation carried out, significant reduction in shear resistance was observed when tension was applied. The results are also compared with existing relationships for headed studs under combined shear and tensile loading to determine which relationship is most reliable in predicting the shear-tension resistance interaction of demountable steel-concrete connectors.