Experimental Studies on Axially Loaded Concrete Columns Confined by Different Materials

The improvement of the load carrying capacity of concrete columns under a triaxial compressive stress results from the strain restriction. Under a triaxial stress state, the capacity of the deformation of concrete is greatly decreased with the increase of the side compression. Therefore, confining the deformation in the lateral orientation is an effective way to improve the strength and ductility of concrete columns. This paper carried out an experimental investigation on axially loaded normal strength concrete columns confined by 10 different types of materials, including steel tube, glass fiber confined steel tube (GFRP), PVC tube, carbon fiber confined PVC tube (CFRP), glass fiber confined PVC tube (GFRP), CFRP, GFRP, polyethylene (PE), PE hybrid CFRP and PE hybrid GFRP. The deformation, macroscopical deformation characters, failure mechanism and failure modes are studied in this paper. The ultimate bearing capacity of these 10 types of confined concrete columns and the influences of the confining materials on the ultimate bearing capacity are obtained. The advantages and disadvantages of these 10 types of confining methods are compared.