Low fines content roller-compacted concrete

Roller-compacted concrete (RCC) is re-emerging as an alternative pavement type to asphalt concrete and even slip-form concrete pavements because of its rapid construction, early opening to traffic, and its economic benefit. The lower cement content of RCC requires careful selection of the aggregate structure to ensure adequate structural performance of the pavement. Recommended gradation bands have been proposed in the literature with few studies systematically investigating aggregate gradation effects on the fresh and hardened properties of RCC. A laboratory study was conducted to quantify the effects of aggregate gradation on the moisture-density relationships and the strength properties of RCC with low fines content. Low fines content RCC mixtures represent the direct application of existing concrete aggregates found in most ready-mixed concrete plants. Optimized moisture-density relationships for nine RCC mixtures with different aggregate gradations and fixed cement content were determined using the modified Proctor test. The compressive and splitting tensile strengths were measured at 14 days and compared with a conventional concrete paving mixture.