Deicer Salt Scaling Resistance of Roller-Compacted Concrete Pavements

Abstract

In the fourth year of a research project of roller-compacted concrete pavements, a test section was cast during the summer of 1990, using four different mixtures. Two types of binder and two binder contents were used to prepare these mixtures. In order to verify if a proper air-bubble network could be obtained, and if it is necessary to have bubbles in RCC to be frost resistant, three of the four mixtures were prepared with an air entraining agent. Based on previous good results, the four mixtures were cured with two different white membrane curing compounds. Samples representative of all mixtures were taken from the pavement after 28 days. The air-void characteristics of all concretes were determined in accordance with American Society for Testing and Materials (ASTM) C 457 and the salt scaling resistance of all mixtures was evaluated using ASTM C 672 on rolled surfaces. Despite the large dosages of air entraining agent used, microscopical examinations clearly indicated that it was not possible to entrain spherical air bubbles in all RCC mixtures. The mass of scaled-off particles after 50 cycles of freezing and thawing in presence of a salt solution is higher than the 1 kg/sq m2 limit for most of the samples tested. Test results also indicate that the construction of a deicer resistant roller-compacted concrete pavement is possible, but only under certain conditions, some of which are not clearly defined. Good construction practices are clearly required. The use of supplementary cementitious materials also appears to be a requirement.