Released: Distress Manual for Interlocking Concrete Pavements

The continual investment in municipal assets, publicly owned infrastructure, is critical to the health of a city. In order to know when to maintain street assets, many cities have developed pavement management systems (PMS), typically computerized databases with formulas to estimate anticipated maintenance costs. The databases provide a means to compare performance among pavements. The Distress Manual and the Pavement Condition software recently released by the Interlocking Concrete Pavement Institute are tools that help city engineers in managing pavements.
 
The guide builds on experience with the interlocking concrete pavement condition index (or PCI) survey method developed by the U.S. Army Corp of Engineers and the American Public Works Association. The distress manual includes a list of interlocking concrete pavement defects which are described, and divided into three levels of severity- high, medium and low. Photographs gathered through many site visits across North America and Europe are included to assist pavement engineers and technicians in applying the distress manual in the field. Each photograph is of distresses at each distress severity level. The guide presents eleven conditions for roads and parking lots. These distresses include rutting, cracked pavers, joint sand loss and others. The procedure evolved from the combined experience of many pavement engineers with asphalt and cast-in- place concrete pavements. The ICPI distress survey and condition forecasting method has been shown to fairly and consistently represent their collective ratings of a wide variety of pavements.  This methodology considers the interactive effect of several distresses on the PCI value and can be used to compare performance of conventional asphalt and concrete pavements.
 
Interactive effects of several distresses are characterized in the Distress Manual using “deduct curves” that reduce the numerical condition rating. These values are included in a software model developed to calculate a PCI from the distress type, extent and severity levels. The deduct curves were validated through field inspections of municipal interlocking concrete pavements. These tools can be incorporated into existing municipal pavement management systems.