PREVENTION OF EARLY PAVEMENT DETERIORATION

This study was done to identify the major forms and causes of early pavement distress, and to recommend changes in specifications or policies to prevent the distress. Three major forms of distress in Utah were identified as follows: 1--Unstable mixes, 2--Transverse cracking, and 3--Stripping. The VESYS IIM rutting model was found adequate in predicting dangerous levels of rutting and shoving of flexible pavements. Higher values of temperature susceptibility, and saturates content in the asphalt binder were found to be related to greater levels of transvers cracking. Usage of the COLD program is promising in reducing temperature-associated cracking. Asphalt-aggregate interactions were found to be related to both unstable mixes and stripping. The analysis of more anti-stripping agents with hydrated lime was recommended for possible use in reducing stripping. It was determined that changes in the marshall mix design method are needed to better represent conditions in the Dryer Drum mixer. A major factor resulting in early pavement deterioration is poor quality control on some highways leading to the pavement not meeting present specifications. /FHWA/