Mixture Design of Exposed Aggregate Concrete Overlay

Bonded concrete overlay is a favorable maintenance method since the material properties are similar to existing concrete pavements. In Korea, the transverse tining method with excellent skid resistance has been applied to bonded concrete overlay for road safety purpose. However, transverse tining produces higher noise level about 4 to 5 dB( A) than the asphalt pavements. To achieve low noise, exposed aggregate concrete pavement (EACP) can become a surface texture in bonded concrete overlay. EACP texture consists of coarse aggregate exposed to the surface around 2 to 3 mm after the removal of cement mortar. EACPs are able to maintain the low noise. In order to apply the surface of bonded concrete overlay with exposed aggregate texture, it is necessary to provide an optimum mixture proportion that satisfies the functional performance as well as the structural performance. Therefore, this study aimed to investigate the optimum mixture design for exposed aggregate concrete overlay based on the structural performance and low noise characteristics that can be affected by cement content, coarse aggregate size, and fine aggregate percentage. The compressive and flexural strength were measured to evaluate the structural performance of exposed aggregate concrete overlay. Also, exposing number of coarse aggregate, and mean texture depth were measured for evaluation of low noise characteristics.