Crack resistance of partially filled narrow steel box-UHPC composite beam
In order to study the crack resistance of partially filled narrow steel box-UHPC composite beams,four partially filled narrow steel box-UHPC composite beams with different steel fiber content and one partially filled narrow steel box-NC composite beam were tested under static loading.The results show that the cracks of the partially filled narrow steel box-UHPC composite beam are numerous,short and dense under the action of negative bending moment.Equivalent reinforcement ratio under the condition of different steel fiber content(0,1%,2%and 3%)steel box-UHPC composite beams with partial filling type narrow narrow steel box-NC part filling type composite beams,compared to its stiffness increased significantly in the elastic stage,the maximum crack width decrease with the increase of steel fiber content,cracking strength by 36.0%,48.8%,82.0%and 112.0%,UHPC significantly improves the crack resistance of composite beams.The crack width of partially filled narrow steel box-UHPC composite beam can be calculated according to the crack width formula in the JTG 3362-2018 by the correction factor of 0.8.