Role of Additives in Compacted Concrete Pavements

Roller compacted concrete (RCC) is an emerging pavement technology especially for secondary roads and is additionally valued for its lower installation costs, faster opening to traffic, high load-carrying capacity, and durability. One major drawback to use of RCC in secondary roads is the balance of smoothness and target surface durability over time. To achieve more consistent RCC mixes, the compaction (flow) performance and rheology of about 40 freshly prepared zero-slump graded aggregate concrete pastes were explored with selected types and levels of additives and water saturation levels. Viscosity modifiers were found to be critical to achieve the highest yield strength formulations. The high yield strength RCC formulations identified from this study followed the key guidance, namely graded aggregate, viscosity, and lubricity, of the Superpave program for fresh asphalt concrete.