Pavement Surface Characteristics Concrete - Rehabilitation (Pooled Fund Study TPF 5(134))
People desire smooth, quiet, and safe pavements. To encourage smooth pavements, we need to quantify the effects of other important pavement performance parameters on ride. These parameters include texture, noise, and friction. An understanding of the interaction of texture and ride is still very rudimentary. In 2002 the MnDOT Concrete Engineering Unit and the Concrete Pavers Association of Minnesota created a test section on TH 212 at Bird Island to study the effects of texture and joints in pavement smoothness. The results showed that profile index was affected by texture and joints. However, data is so far insufficient to define a global correlation between texture values and their effect on ride, and the results obtained for the effects of joints on ride were not conclusive because of unanticipated construction issues.
One option is for rehabilitating Portland cement concrete pavements without the need to restore structural capacity is to diamond grind the surface. This process removes much of the pavement roughness and restores texture and friction. Many variables play into the grinding operation, such as blade spacing, depth of cut, kerf configuration, etc. There is a need for a standardized specification for diamond grinding. These parameters affect and govern the preponderant frequencies that cause noise when such frequencies are not randomized. Power spectrum density analysis of results obtained in the Bird Island Test section as well as profilometer-generated roughness showed that diamond grinding did improve the ride. The resulting texture and noise were not measured until 2005 when the FHWA PSC study team measured the site. Minor changes in the geometry of diamond grinding equipment tremendously affect the friction and noise performance, but the optimum geometry is still unknown.
Pooled Fun Study