PCC Surface Characteristics–Rehabilitation
(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 Mn/DOT 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. Minor changes in the geometry of diamond grinding equipment tremendously affect the friction and noise performance, but the optimum geometry is still unknown.

A current Purdue University study is expected to provide recommendations on pavement surface textures that can provide desirable levels of safety and reduction in noise levels. Along with that may come some recommendations on grinding operations so as to mitigate noise issues. The research in this pooled fund study will validate the recommendations from Purdue.

As public demand for quieter pavements increases, this study can lead to improved methods for modifying existing PCC pavements to make them quieter without sacrificing friction. Research findings will enable transportation agencies to specify ranges of values for friction, ride, and texture that will optimize quietness, ride, texture and friction in program delivery, thereby reducing the incidence of uncomfortable ride, hydroplaning, and obnoxious whines.

This research will enable prediction of noise level based on the grinding techniques. The project will provide data for optimization of pavement quietness, friction, texture and ride. We will be in a better position to improve our diamond grinding and texture specification if necessary. It will address the question as to what degree of total noise is generated by tire-pavement interaction. Monitored over time, performance versus time characteristics will be obtained for various grinding techniques.