The grout injected into a post-tensioning duct is often the last line of defense against corrosion of the tendon. Corrosion protection of the post-tensioning system is vital to the integrity of the structure because loss of post-tensioning can result in catastrophic failure. Inspection of the tendons is frequently difficult, particularly for internally post-tensioned structures, and severe corrosion may go unnoticed in a tendon due to the lack of obvious visible warning signs. A series of tests for workability and bleed resistance along with accelerated corrosion tests were used to develop high performance grouts that combine favorable fresh properties with good corrosion protection. The grouts were then pumped into a large-scale clear draped parabolic duct to observe their workability, flow behavior, and bleed resistance under simulated field conditions. Due to the increased importance of bleed resistance in structures with large vertical rises, two high performance grout designs were developed. A fly ash grout was developed for primarily horizontal applications and a grout showing strong thixotropic properties was developed for vertical applications. Post-tensioned beam specimens were fabricated for long-term corrosion testing. These specimens include the fly ash and anti-bleed grouts developed in the grout testing phase along with the Texas Department of Transportation standard grout. The long-term corrosion testing is ongoing.
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