Optimum moisture content in roller-compacted concrete pavement

摘要

Roller-compacted concrete pavement (RCCP), named from a construction method, is a drier mix-stiff enough to be compacted by a vibratory roller. RCCP's fresh and hardened properties are considerably influenced by a mix water. The maximum density method, having optimum moisture content at maximum dry density, is most commonly used for the mix proportioning of RCCP. In this study, engineering properties of RCCP at different moisture contents of 4.5%, 5%, 5.5%, 6%, 6.5%, 7% and 12% cement were investigated. Test results showed that an increase of moisture content from 4.5% to 7% decreases the Vebe time from 45 to 22 s. The RCCP at 5.7% moisture content had the maximum dry density, while best mechanical performance, lowest porosity and water absorption values were obtained at 5% moisture content. This study concluded that a workable, high strength and durable RCCP can be made with a moisture content less than the optimum moisture content, which is corresponding to the maximum dry density.