Eccentric Tensile Behavior of Steel-Steel Fiber Reinforced Concrete Composite Bridge Deck

Abstract:

In order to investigate the mechanical characteristics of steel-steel fiber reinforced concrete （SFRC） composite deck under eccentric tension load in the main girder system， eccentric tension tests of normal concrete composite bridge deck and SFRC composite bridge deck specimens， together with finite element analyses based on the plastic damage model of materials were executed. The influence of SFRC on failure form， stiffness reduction and strain distribution of composite bridge deck under eccentric tension load were investigated. The test and numerical analysis results showed that， compared with normal concrete， SFRC presented characteristics of more cracks but smaller crack width during the development of tensile cracks. By observing the strain development and distribution of reinforcements， SFRC could continue to bear external load after cracking due to its tensile hardening property. After cracking， the contribution of SFRC to axial tensile stiffness and lateral bending stiffness of composite deck was significantly greater than that of normal concrete. When the maximum crack width was 0.10 mm and 0.20 mm， respectively， the contribution of SFRC to axial tensile stiffness of composite deck was 36% and 22%， while that of normal concrete was only 15% and 11%； the contribution of SFRC to lateral bending stiffness of composite deck was 41% and 27%， while that of normal concrete was only 29% and 17%. In addition， combined with theoretical derivation， the ultimate bearing capacity of composite deck under full section yield of steel was analyzed. The results showed that the contribution of SFRC and normal concrete to ultimate bearing capacity of composite deck was not significant.

Key words:main girder system;steel fiber reinforced concrete（SFRC);composite bridge deck;eccentric tension;Stiffness change