Coreslab enables New Mexico State ultra-HPC girder research

Sources: New Mexico State University (NMSU), Las Cruces; CP staff

With specimen production and handling assistance from Coreslab Structures in Albuquerque, an NMSU graduate student team is conducting flexural tests on large-scale prestressed girders designed with steel fiber-reinforced, ultra high performance concrete mixes, to be followed by similar testing on full-scale beams.

Under Assistant Professor of Civil Engineering Brad Weldon, it aims to a) advance the state’s bridge design procedures and extend current structures’ typical 50-year service life three-fold; and, b) obtain flexural behavior data to evaluate design procedures central to development of standardized codes. The initial specimens are the largest scale girders to date fabricated with the UHPC formulation, as previous tests had been limited to small rectangular beams.

UHPC can have compressive strengths exceeding 22,000 psi. Its unique material properties, along with steel fiber specification, are not accounted for in the common design standards. The NMSU tests will provide a realistic representation of how full-scale UHPC beams behave in a bridge. The civil engineering team will deploy a floor-anchored testing frame—incorporating recycled bridge girder components—designed to measure specimens’ resistance to loads.

Joining Coreslab Structures with donation of equipment, materials and labor required for the girder testing are Jobe Materials (ready mixed for specimen bridge decks), BASF Admixture Systems, Bekaert, Dayton Superior Corp., and Voss Engineering. The NMSU MTECH Lab assisted in customized testing equipment assembly. Leading the student team is Andrew Geisler, who received funding through a Precast/Prestressed Concrete Institute-administered Daniel P. Jenny Research Fellowship.