CREEP BEHAVIOR OF CONCRETE-FILLED STEEL TUBULAR ARCH RIB

Based on the creep characteristics of concrete filled steel tubular (CFST) arch bridge, a series of stress redistribution formulae were proposed to predict the time-dependent effect on CFST arch rib by introducing the concrete transformed modulus of elasticity. A scaled segmental experimental model of CFST arch bridge was fabricated to investigate concrete creep behavior. By comparing the experimental results with the calculated ones based on the standard code under serviceability limit states, the effectiveness of this method was confirmed. It was concluded that during creep stress increased in steel tube, while decreased in concrete. The maximum stress reduction caused by concrete creep was 52.7% of the concrete initial stress, whereas the maximum stress increment in steel tube was 27.3%. Several parameters such as loading level, steel percentage and rise-span ratio were investigated to evaluate the long-term effects of CFST structures. Moreover, creep behavior of CFST arch rib under ultimate limit states was investigated.