The Control Of Frost Action With Respect To Design Of Concrete Pavements

Experience has indicated that the special design and construction features required to mitigate pavement damage due to frost action can result in significantly higher road construction/rehabilitation costs when compared to standard construction. If frost action is not controlled, permanent pavement deformation, damage to utiilties and overall poor road performance will result in escalated and untimely pavement rehabilitation. A 'standard' flexible pavement constructed in non frost-susceptible conditions could anticipate a normal service life of 12 to 15 years; the same pavement structure could require major maintenance within 5 years when constructed in an area where frost-susceptible subgrades are a problem. Over the past several years, a number of frost action mitigation procedures have been developed and implemented in the District Municipality of Muskoka to control, not eliminate, frost action. Subsequently, a joint Ontario Good Roads Association (OGRA)/MTO sponsored demonstration project has been undertaken by the District Municiaplity of Muskoka to document tohe performance of these frost action mitigation measures and construct tiral sections using the most favourable methods for full performance monitoring and cost benefit analysis and to assist in the development of new standards for rura./urban roads in areas of severe frost action. These trial sections were constructed in the fall of 1992 with the final asphalt concrete surface course placed in June, 1993. For the covering abstract of this conference, see IRRD number 863140.

The information presented herein concerns the basic considerations of the frost action problem: namely, water temperature, soil, and the freezing mechanism of soil-water systems.

The growth of roller-compacted concrete pavement use in cold climate regions often is impeded by concerns regarding its ability to resist frost attack. Most published laboratory test results have indicated that the frost resistance and particularly the deicer salt-scale resistance of RCC are not always satisfactory. However, long-term field performance indicates that non-air entrainment RCC can be quite resistant to frost action. The report provides a comprehensive review on the current practices and recent developments in material selection and aggregate gradation, mixture design methods, production process and placement techniques. Improved construction techniques and recent developments in mixture design methods have resulted in stronger more durable RCC. Data shows that as little as 1.5% of spherical air bubbles can have a beneficial influence on the frost resistance durability of RCC. Test results indicate that ASTM C 1262 appears to be a reliable method of assessing the frost durability of RCC.