Influencing compressive strength of roller-compacted concrete

Roller-compacted concrete is a type of zero-slump concrete that usually has a higher compressive strength than ordinary concrete, with the same cement content. This is primarily due to the high level of aggregate interlock achieved by compaction, but many other factors are also involved. The goal of this study was to investigate the influence of aggregate gradation, cement content, water content, compaction effort, curing conditions and admixtures on the compressive strength of roller-compacted concrete. It was found that aggregate gradation within the limit recommended by the Portland Cement Association is desirable for high compressive strength. The concrete becomes less sensitive to water content when the cement content is augmented, and a minimum of 98% modified Proctor dry density ratio is needed to achieve the maximum strength. Moderate strength improvement can be obtained with moisture control during the curing process, and it is possible to extend working time by using admixtures without compromising strength.