Grouts for bonded post-tensioning in corrosive environments

Problems with corrosion of prestressing steel in post-tensioned structures due to inadequate grouting in the past have become more apparent in recent years. To improve grouting practices, a series of fresh property tests, accelerated corrosion tests, simulated field testing, and long-term corrosion testing were used in this study to develop optimum grouts for post-tensioning. Grouts possessing adequate workability and bleed resistance were tested in an accelerated corrosion test to evaluate relative corrosion protection properties. This paper focuses on the accelerated corrosion test results. The most promising of these grouts were then tested for placeability under simulated field conditions. A fly ash grout and a thixotropic grout are recommended from this testing program. Additionally, an important benefit from this testing was fluidity, bleed, and corrosion resistance data acquired for a number of different combinations of pozzolans and admixtures.