Frost Durability Of Roller Compacted Concrete Pavements

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.

Concrete durability in climates where freezing and thawing occurs is a continuing problem. It is particularly acute for highway and bridge structures, where de-icing salts are used to combat the effects of frost, snow and ice. These salts can cause damage to concrete and accelerate corrosion of reinforcements. This book presents the latest international research on this area, with contributions from North America and Europe which were presented at an international RILEM workshop.

Roller-compacted concrete (RCC) pavement use a paving technique in which a zero-slump portland cement concrete mixture is placed using asphalt concrete pavers and compacted with vibratory and rubber-tired rollers. A reason for using RCC pavements is its durability in freezing and thawing conditions. Conventional concrete pavements are air-entrained for protection in freezing and thawing conditions. However, attempts to air-entrain RCC mixtures have met with little success. Nonair-entrained RCC has performed well in freezing and thawing field conditions in the past, but laboratory samples have demonstrated poor frost resistance. Objectives of this study are: (a) to determine if a proper air-void system can be entrained in RCC pavement mixtures using various dosage rates and aggregate gradings, and (b) to evaluate frost resistance and investigate material, construction, and site conditions which might influence the frost resistance. Results of the study demonstrated that various RCC mixtures may be entrained with air voids sufficient to protect the concrete from frost damage. RCC may also be effectively air-entrained in field applications. Studies of selected sites have shown that nonair-entrained RCC pavements have performed well in freezing and thawing climates. Keywords: Air entrainment/voids; Pavements/frost heave; Frost/resistance; Aircraft/parking facilities; Concrete/mixtures; Construction materials. (MM).

An investigation was conducted to evaluate the frost resistance of samples taken from roller-compacted concrete (RCC) pavements using laboratory testing procedures. Nine existing pavements were sampled and tested for microscopical determination of air-void content and parameters of the air-void system, resistance to rapid freezing and thawing, critical dilation, and compressive and flexural strength. The pavements ranged in age from 1 month to 8 years at the time of sampling. Preliminary results of the dilation tests indicate that those samples judged to be frost susceptible when tested by rapid freezing and thawing, may, in fact, offer some degree of frost resistance. The dilation test may be appropriate, therefore, to determine whether a RC sample is frost resistant at the time of test or to measure the period of frost immunity.

This book provides a comprehensive and authoritative review of durability of the frost resistance of concrete. It will enable both concrete materials specialists and practising engineers to better understand the deterioration processes which take place during freezing and thawing, and the effects of de-icing salts on concrete. It shows how test pro