Self-Consolidating Concrete for Prestressed Bridge Girders

2017November 2014 - July 2017PDFTech Report0092-15-03Project 0092-15-03CreepGirder bridgesMix designPrecast concretePrestressingRecommendationsSelf compacting concreteShrinkageStructural analysisSelf-consolidating concreteprestressed bridge girderfresh propertieshardened propertiesprestress lossestransfer lengthfield testingUnited StatesWisconsinWisconsin. Dept. of TransportationSeo, JunwonTorres, EduardoSchaffer, WilliamSouth Dakota State University. Dept. of Civil and Environmental EngineeringWisconsin. Dept. of TransportationWisconsin Highway Research ProgramUnited States. Federal Highway AdministrationDoocy, SteveUS Transportation CollectionThis document reports the findings of a research project designed to better understand material and structural performance of prestressed bridge girders made with Self-Consolidating Concrete (SCC) from Wisconsin. SCC has high potential to be used for prestressed bridge girder construction due to exceptional workability and strength. However, many local precasters have struggled to maintain uniformity in SCC mixtures, in order to achieve consistent, desirable performance, which are ultimate concerns to Wisconsin Department of Transportation (WisDOT). Hence, the ultimate objective of this project was to develop widely accepted, uniform recommendations on SCC mixture design that achieves desired performance for the use of SCC in WisDOT bridge projects. To that end, this project initially investigated the effects of material constituents (e.g., cement type) on the fresh and hardened properties of trial SCC mixtures made from precastors in Wisconsin. A small group of SCC mixtures were identified based on the experimental investigation of results, technical findings from a comprehensive literature review, and additional input from the Project Oversight Committee (POC) and a survey to several DOTs. The identified SCC mixtures were tested at precasting plants for the evaluation of their material performance. With a detailed investigation of the results, high quality SCC mixtures were selected and used to build cylinders and prims for the evaluation of their creep and shrinkage for a period of 280 days. Based on the investigation of the results, the most appropriate SCC mixture was selected to fabricate a full-scale SCC girder to verify structural performance, including prestress losses, transfer length, and camber. The results of the SCC girder were compared to those of a Conventional Concrete (CC) girder that was fabricated to be utilized as a reference girder. Then, field monitoring of prestress losses of both girders that were installed in a WisDOT bridge, was made from its erection to deck placement. At the end of this project, recommendations for SCC mixture design were established to promote SCC in prestressed bridge girders in Wisconsin. Key findings indicate that the full-scale SCC and CC girders exhibited the almost identical long-term camber and prestress losses, but the transfer length of SCC girder was somewhat lesser than that for the CC girder