Evaluation of Rapid-Setting Concretes for Airfield Spall Repair.

摘要

Three commercially available, off-the-shelf, rapid-setting materials were evaluated for their potential as spall-repair concrete for Rapid Runway Repair (RRR). The three were a methyl methacrylate binder (Silikal R17AF), a magnesium phosphate mortar mix (Set-45), and a high-performance blended cement mortar mix (Pyrament 505). Each was extended 50 percent by mass with coarse aggregate for these tests. Test methods were chosen, or developed as required, to evaluate the performance of these three rapid-setting concretes in cold and wet conditions, as well as at room temperature. None of the materials performed ideally under all conditions. Silikal R17AF gives very high strengths in cold, dry conditions. But it bonds poorly to wet surfaces and loses much of its strength when mixed with wet aggregate. Pyrament 505 gains strength more slowly, especially at temperatures below 20 F, but it bonds consistently well under all conditions tested. The Set-45 product evaluated could not be tested at temperatures below 40 F, due to insufficient strength even for removing specimens from the molds.