Fatigue performance of singular and modular press-brake-formed steel tub girders

摘要

The concept of cold-bent shallow press-brake-formed steel tub girders was developed by a technical working group within the Steel Market Development Institute's (a business unit of the American Iron and Steel Institute) Short Span Steel Bridge Alliance, led by the current authors. This working group consists of all stakeholders in the steel bridge industry, including mills, fabricators, service centers, industry trade organizations, universities, and bridge owners. The scope of this effort is defined by three separate tasks. First, singular composite girders were fatigue tested by simulating a 75-year life in a rural environment. Second, two slab edge treatment methods were evaluated to determine the optimal option for the Ultra-High Performance Concrete (UHPC) joint between modular tub girder units. Lastly, two composite modular press-brake-formed tub girders were connected longitudinally with a UHPC joint and the system's fatigue performance was evaluated. Experimental results show press-brake-formed tub girders behave adequately with respect to fatigue. Longitudinal joints composed of UHPC behaved satisfactorily throughout testing.