Welded wire reinforcement versus random steel fibers in precast/prestressed ultra-high performance concrete I-girders

The high shear capacity of ultra-high performance concrete (UHPC) AASHTO Type II girders tested at the Federal Highway Administration labs resulted in interest by state highway agencies in applying UHPC in bridge construction. UHPC superior shear capacity results from the random steel fibers incorporated in the mix. However, steel fibers significantly increase the mix material cost (fibers cost $400 per cubic yard). This paper presents a study to compare the structural efficiency and economical feasibility of replacing random steel fibers with grade 80 welded wire reinforcement meshes. Two AASHTO Type II girders were fabricated using non-proprietary UHPC mixes developed at the University of Nebraska – Lincoln and reinforced with WWR in replacement of steel fibers. The test results showed that WWR resulting shear capacity exceeds random steel fibers. The WWR cost effectiveness and ease in construction could accelerate the application of non-proprietary UHPC and WWR in bridge construction.