Mix Design Method and Void Performance of Concrete for Pervious Concrete Pavement

Pervious concrete pavement is drawing increasing attention for its high content of interconnected voids which is expected to reduce the environmental impact as concrete is often counted as a causal factor of the urban heat island phenomenon. Performance of pervious concrete can be measured by water permeability, water retentivity and noise reduction effect. Although active research is being made, no established standards or indicators for pervious concrete are available in Japan. Terms are not defined yet, and no method has been established for mix design. The purpose of this study is to present a mix design method that provides pervious concrete with a design void content and required performance level. The authors developed a theoretical model of pervious concrete under different void conditions, derived theoretical equations of void content from the model, and proposed a mix design method using the theoretical equations for pervious concrete for pavement. The proposed method takes into account the physical properties of the aggregate including solid volume percentage in addition to the densities of the materials. The close relationship between the strength and water permeability of pervious concrete and the physical properties and void structures of the materials was confirmed both experimentally and analytically.