Thin whitetopping (TWT) is a 4- to 7-in. thick concrete overlay bonded to an existing asphalt concrete pavement (ACP) to create a composite section (see Figure 8-7). TWT is constructed normally at intersections where rutting and shoving in asphalt pavement continue to cause problems. TWT may also be used at access or exit ramps to interstate highways, entire sections of urban roadways, low-volume rural roads, bus lanes, and parking areas. TWT provides better serviceability, longer service life, lower life-cycle cost, and improved safety.

This rehabilitation technique purposely seeks to bond the concrete overlay to the existing asphalt. The composite action significantly reduces the load-induced stresses in the concrete overlay. Therefore, the concrete overlay can be significantly thinner for the same loading as compared to a whitetopping section with no bond to the underlying asphalt. TWT will significantly reduce time and delays accompanying the frequent maintenance of an asphalt surface.