High Performance Concrete for Bridge I-Girders

High Performance Concrete (HPC) is a new type of concrete made with selected high quality constituents, optimized mix design, and low water-to-powder ratio. According to the American Concrete Institute (ACI), HPC is defined as concrete meeting special combination of characteristics and uniformity requirements. HPC cannot always be achieved using conventional mix constituents or regular mixing and quality control procedures. The objective of this research is to develop economic, self-consolidating high performance concrete mixes to be used in the precast industry of bridge I-girders. The produced mix attains a minimum 28-day strength of 15 ksi., mixing time below 20 minutes to avoid the formation of cold joints upon girders’ fabrication, and self-consolidating workability (spread diameter of 23 inches or more). Designed mixes were used to fabricate prestressed girders. Steps of mix design are mentioned. Developed HPC were used in fabricating high strength girders for full-scale testing. The girder test results proved the superior performance of the developed HPC mixes in shear and flexure. HPC mixes are economic to use in fabricating I-girders due to their higher strength and expected long-term durability.