Experimental studies on cracking behavior of steel fiber reinforced concrete slab in negative moment region of orthotropic composite bridge deck

In order to study the stressing performance of steel-steel fiber reinforced concrete composite bridge deck，especially the influence of steel fiber reinforced concrete on the concrete cracking performance of the bridge deck in the negative moment region of the composite bridge deck. Two orthotropic composite bridge decks were designed and manufactured，one of which was a conventional C60 concrete composite bridge deck and other was a steel fiber reinforced concrete composite bridge deck. The static tests of two composite bridge deck were carried out. The experiment tested the deformation of two bridge decks under different loads，the strain of each member on different sections，the width of concrete cracks，the failure mode and the ultimate load carrying capacity. The existing standard formula for flexural bearing capacity of composite bridge decks was amended，and a recommended formula for flexural bearing capacity considering the residual strength of steel fiber reinforced concrete after cracking was proposed. The tests show that the initial cracking load of the steel-steel fiber reinforced concrete composite bridge deck are 3.5 times higher than those of the conventional C60 concrete composite bridge deck respectively. Using steel fiber reinforced concrete instead of conventional C60 concrete as the composite bridge deck can greatly improve the cracking resistance of the concrete in the negative moment region of the orthotropic composite bridge deck. At the same time，the proposed formula has high accuracy and can effectively predict the flexural bearing capacity of the orthotropic steel-SFRC composite bridge deck，providing a theoretical reference for practical engineering applications. © 2023 Editorial Board of Jilin University. All rights reserved.