DEVELOPMENT OF A PAVEMENT CONDITION RATING PROCEDURE FOR INTERLOCKING CONCRETE PAVEMENTS

Most North American cities are using a pavement management system (PMS) for their streets to budget maintenance and future rehabilitation costs. PMS is a programming tool that collects and monitors information on current pavement conditions and forecasts future performance and conditions. This enables city officials to evaluate and prioritize alternative reconstruction, rehabilitation, and maintenance strategies to achieve a "steady state" of system preservation at an optimal level of performance. The condition data in a PMS database can also be used as an engineering tool to evaluate the real-life performance of pavement thickness design, mix design, material composition, and construction specifications. Many municipal PMS programs incorporate pavement condition evaluation guidelines that follow the U.S. Army Corps of Engineers MicroPAVER distress guide (published by ASTM) to evaluate flexible and rigid pavements. The procedure consists of a methodology to evaluate pavement surface distresses in terms of type, extent and severity and combines this information to develop a standard pavement condition index. While there has been some research completed to develop methods of evaluating the condition of interlocking concrete pavements (ICP’s), there is no common methodology currently in practice in North America. This paper outlines the procedures used to develop a pavement distress guide for flexible ICP’s following the MicroPAVER protocol. The paper provides an overview of the procedures used to develop the distress guidelines for interlocking concrete block pavements, summarizes the results of the analysis and provides an example of the use of the procedures to determine the pavement condition index for a roadway constructed using ICP’s as a running surface. In support of this effort, a detailed literature survey of pavement management tools was completed and a list of typical interlocking concrete block pavement distress features and photographs of these features was compiled. The influence of each of the distresses on the performance of the pavement was determined through consultation with industry and other design professionals. Influence functions were then developed for each distress type and severity to permit the calculation of “deduct” values. The deduct values are then combined to determine the overall pavement condition index (PCI) for the pavement section. Keywords: Interlocking concrete block, pavement management, MicroPAVER, lifecycle costing, pavement condition monitoring.