Development of design methodology for continuously reinforced bonded concrete overlay pavements: a case study of Korean expressways

Many sections of concrete pavements on Korean expressways have reached or exceeded their 20-year design life, requiring large-scale rehabilitation. This study proposes a selection method and design catalog for concrete overlays on deteriorated concrete pavements. Based on the premise that an overlay should provide structural capacity equivalent to that of a new pavement, the catalog determines the milling depth of the existing slab, continuously reinforced bonded concrete overlay (CRBCO) thickness, and maximum rebar spacing considering existing slab thickness and condition, traffic volume, and rebar diameter. The developed catalog was applied to an experimental CRBCO project. Four weeks after construction, reflection cracks developed immediately above several joints of the existing pavement, as anticipated. The measured crack widths remained within the criterion adopted in the design catalog, while long-term monitoring is required for further verification.