Guide Specification for HPC Bridge Elements

摘要

The Federal Highway Administration (FHWA) encourages the use of high performance concrete (HPC) to improve the long-term performance of the nation's infrastructure at lower life-cycle costs. For its purposes, the FHWA uses 11 performance criteria to define high performance concrete, and it designates three levels of performance for each criterion, with Grade 3 being the most stringent. For FHWA projects, the specifier is expected to select the criteria necessary for a given element, and then select an appropriate performance grade. It's not necessary or desirable to specify the same performance grade for all characteristics. Guide Specification for High Performance Concrete for Bridge Elements provides mandatory language that the specifier can cut and paste into project specifications, as well as guidance on what characteristics should be specified in a given case, and what criterion is needed to ensure satisfactory performance. It includes commentary that tells how to obtain the desired performance for each characteristic. In cases where two performance criteria are in conflict, the commentary advices the user how to balance conflicting requirements.