Influence of Freezing and Thawing Action on Abrasion Resistance of Mortar Materials

Abstract

The objectives of this study are to evaluate the effects of freeze-thaw action on the abrasion resistance of a cementitious surface coating material. We prepared both air entrained (AE) and non-air entrained (nAE) Ordinary Portland Cement mortar beams with water-cement ratios of 40, 50 and 60%. After freezing and thawing tests were conducted on these specimens, they were subjected to the water jet abrasion test to investigate the effects of freeze-thaw action on their abrasion resistance. In the AE specimens after the freeze-thaw tests, the relative dynamic moduli of elasticity were over 90%, and the progress of degradation due to freeze-thaw was small. In the nAE specimens after the freeze-thaw tests, the relative dynamic moduli of elasticity were less than 40% at the maximum at the placement surface, 70-80% at the bottom surface, and 80-90% at the specimen center. Deterioration due to freeze-thaw progressed on the both surface layer. In addition, there was a difference in the progress of deterioration depending on the part of the specimen. The average wear depth of the mortar specimens after water jet abration test becomes smaller as the W/C is smaller and the surface quality is more dense in the initial state before being subjected to freeze-thaw action. The average wear depth of the mortar specimens after the freeze-thaw test increases as the relative elastic moduli of the specimens around surface layer decreases due to the freeze-thaw action. In this test, the abrasion resistance of the mortar containing after the freeze-thaw test was significantly improved by the addition of AE admixtures. This result suggests that the use and management of appropriate AE admixtures are important for securing frost damage resistance of mortar materials in frost damage environment.