Performance of the First Structure Built with High Performance Concrete in Virginia

About the report:

This study evaluated the preparation and placement operations, concrete properties, cost-effectiveness, and performance over 5 years of the first bridge containing high performance concrete built by the Virginia Department of Transportation. High performance concrete was used in the prestressed beams and cast-in-place substructure and deck concrete. The concrete in the beams contained silica fume, and that in the cast-in-place substructure and deck contained slag. A high compressive strength was specified for the prestressed beams, normal strengths were specified for the cast-in-place substructure and deck concretes, and low permeability was specified for all the concrete. Steam-cured specimens for the beams had high early strengths, but moist-cured specimens developed higher long-term strengths. The permeability was much lower than specified. Concretes were easily placed, and the strengths were higher than specified. The structure was monitored during construction and surveyed after construction and at 5 years. Some cracking occurred in the deck, but the cracks were tight. The author recommends that high-strength concrete be used in beams if economically feasible. Temperature-matched curing should be used to determine the strength of elements where high temperature increases are expected, and pozzolans or slag should be used to reduce permeability.

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