Abstract
Concrete filled steel tube (CFST) is increasingly used in engineering construction as columns and beams. CFST is known to absorb large amounts of energy as a result of the composite effect. Internationally, there are increasing amounts of waste rubber. In this study recycled rubber is used as aggregate supplement in concrete. Rubberised concrete is known to be more ductile than conventional concrete however has a lower compressive strength. This study investigated the performance of thirty rubberised concrete-filled single-skin steel tubes under combined loading conditions and compared the results against six steel hollow tubular members. Three rubber replacement ratios, 0%, 15% and 30%, three load eccentricities and four tube sections with section slenderness (b/t, width/thickness) of 18 to 36 were examined. The results have shown that the composite section had greatly improved load carrying capacity. The ductile rubberised concrete was more effective in delaying the premature buckling failure of the steel tube compared to the normal concrete. The interaction diagrams were constructed from the experiments and theoretical calculations. It was found that the behaviours of the rubberised concrete filled steel tubes could be accurately predicted using existing design guidelines. This study demonstrated the potential of using rubberised concrete as a cost-effective solution to safe roadside barriers and structural members in buildings located in seismic active zones.
Highlights
Concrete filled steel tubes (CFST) are increasingly used in engineering construction as columns and beams
To mitigate the significant reduction in strength, steel tubes may be filled with rubberised concrete to form rubberised concrete filled steel tubes (RuCFST)
The RuC15 and RuC30 filled steel tubes were 9.3% and 19.1% weaker, respectively, than those filled with the much stronger normal concrete (NC). This showed RuCFST had adequate strength to be adopted as structural members
Summary
Concrete filled steel tubes (CFST) are increasingly used in engineering construction as columns and beams. The concrete provides restraint to buckling of the steel tube increasing its strength and ductility. The steel tube provides confinement of the concrete increasing its strength. In Australia and internationally there are increasing amounts of waste rubber being generated It is an environmental, health and fire hazard, and costs millions of dollars to dispose every year [2,3]. The rubberised concrete (RuC) has improved mechanical properties such as ductility, fracture toughness and energy absorption compared to the normal concrete (NC), with reduced compressive strength and stiffness. The confinement of the rubberised concrete increases its strength in the same way as standard concrete. Confined rubberised concrete has high ductility and as such it can maintain its strength after yielding unlike standard concrete. In particular there is a lack of knowledge relating to the behaviour of RuCFST under combined loading
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
