Characterization of Self-Consolidating Concrete for Design of Precast, Prestressed Bridge Girders

摘要

This report documents the findings of a Texas Department of Transportation sponsored research project to study self-consolidating concrete (SCC) for precast concrete structural applications. Self-consolidating concrete is a new, innovative construction material that can be placed into forms without the need for mechanical vibration. The mixture proportions are critical for producing quality SCC and require an optimized combination of coarse and fine aggregates, cement, water, and chemical and mineral admixtures. The required mixture constituents and proportions may affect the mechanical properties, bond characteristics, and long-term behavior, and SCC may not provide the same in-service performance as conventional concrete (CC). Different SCC mixture constituents and proportions were evaluated for mechanical properties, shear characteristics, bond characteristics, creep, and durability. Variables evaluated included mixture type (CC or SCC), coarse aggregate type (river gravel or limestone), and coarse aggregate volume. To correlate these results with full-scale samples and investigate structural behavior related to strand bond properties, four girder-deck systems, 40 feet (12 m) long, with CC and SCC pretensioned girders were fabricated and tested.