UTC 2022 Funding - Cycle 1 Research Projects

Project No.: CY1-OU-04
Title: Bond Performance of Advanced Environmentally Friendly Concrete Materials for Rapid Infrastructure Repair and Rehabilitation
Performing Institution: University of Oklahoma
Principal Investigator: Royce Floyd, Jeffery Volz, Shreya Vemuganti, University of Oklahoma
Start and Anticipated Completion Dates: 10/1/2023-09/30/2024
Abstract: Portland cement production results in approximately 2.5 gigatons of direct CO2 emissions per year, or between 5% and 10% of CO2 emissions produced by humans. Calcium sulfoaluminate (CSA) cements are a promising alternative to hydraulic cements because of the significant reduction (nearly half) in CO2 emissions during production and high early strength (rapid setting) or controlled expansion (shrinkage compensating). These properties make CSA cement attractive and effective for transportation infrastructure, including accelerated repair of pavement and/or mitigation of shrinkage cracking. Half of the bridges in the United States already have or will reach their anticipated design life in the next 10 years. Many of these bridges can have their service life safely extended – with reduced environmental impact – by targeted repair and rehabilitation using CSA cement. Using concrete mix designs developed at the University of Oklahoma (OU), the University of Arkansas, and Louisiana State University, the proposed research will evaluate the ability of CSA cement to bond to traditional concrete substrates and the durability of those bonds over time. The objectives of the proposed study are to (1) Evaluate the bond performance of CSA cement concrete for varying substrate conditions; (2) Evaluate the freeze-thaw durability of CSA cement concrete repairs; and (3) Develop and communicate recommendations for CSA cement concrete repairs. These objectives will be achieved by experimental evaluation of CSA cement concrete mix designs developed at OU and SPTC partner institutions through six specific tasks. Task 1 will involve identifying CSA cement concrete mix designs for use in further testing. Task 2 will examine the bond of the CSA cement concrete repair materials to conventional concrete substrates with different surface preparations, using direct pull-off testing. In Task 3 freeze-thaw resistance of the repair interface will be evaluated using rapid freeze-thaw cycles. Repaired interfaces for both newly cast specimens and concrete from in-service bridges will be tested for freeze-thaw resistance. In Task 4 bond and freeze-thaw results will be compared with the results for other advanced concrete materials. Task 5 will involve the construction of a large-scale repair demonstration for DOT officials that will then be used for long-term performance evaluation. Task 6 will include the development of educational materials including a prerecorded training module, a live workshop, and a demonstration for high school outreach events. This project will provide mix designs and data on the bond behavior of CSA cement-based repair materials to concrete substrates of varying conditions and surface preparations, as well as recommendations for mix designs and surface preparations for repair using CSA cement concrete. CSA cement concrete for repair of existing transportation structures will allow more rapid repairs/rehabilitations that reduce the impact on the traveling public while extending the life of existing structures.
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