2015 CSCE Annual Conference Regina - Building on our Growth Opportunities Conference
Dr. Mahmoud Sayed Ahmed, Ryerson University
Dr. Khaled Sennah, Ryerson University
Mr. Philip Zacarias, St. Marys / Canada Building Materials
Mr. Salih Judieh, Ryerson University
There is a growing need for durable and resilient prefabricated bridge systems which facilitate rapid completion of on-site activities in order to minimize the impact on the travelling public. Prefabricated bridges can provide higher quality, accelerated, and safer construction; however, greater offsite prefabrications of bridge components necessitates an increased reliance on the long-term performance of field-installed connections between these components. Of particular interest here, UHPCs can exhibit exceptional bond when cast against previously cast concrete and can significantly shorten the development length of embedded discrete GFRP bars. With the recent innovations in bridge infrastructure replacement and construction using “accelerated bridge construction technologies”, the use of UHPC in closure strips between precast concrete segments in fabricated bridges construction became the main focus of bridge owners for its superior strength and durability. To increase competitiveness in supplying UHPC to bridge owners in Canada, this collaborative research with the industry is looking into an innovative UHPC design that combines both high concrete compressive strength, and enhanced durability and rheology. It is essential to produce design standards and performance-based specifications of UHPC through experimental trial and errors due to lack of reliable information in this subject in the related standards and literature. This research investigates different mixes designed to reach the desired strength and rheology. While UHPC materials clearly outperform conventional concrete in mechanical and durability performance, their production is proprietary and the development of economically competitive alternatives is warranted. This paper summarizes phase I of this research project to develop UHPC mix with target rheology and compressive strength characteristics. Throughout this phase, the desired fresh and hardened concrete properties as well as practical mixing procedure were achieved and reported herein.