INVESTIGATION OF THE FRICTIONAL RESISTANCE OF SEAL COAT PAVEMENT SURFACES. INTERIM REPORT

Numerous factors, including aggregate characteristics, construction variables, traffic volume, and environment, are believed to be affecting the frictional performance of highway pavements. The objective of this phase of the study was to investigate the effects of these factors on the field frictional resistance of seal coat surfaces. The investigation involved establishing seal coat test sections in different climatic regions in the State of Texas with various aggregate types and sources and under different traffic volumes. Samples of the aggregates used were examined in the laboratory to determine their physical properties, polish and wear characteristics, resistance to weathering, resistance to impact and abration, and petrographical and mineralogical qualities. Field tests which involve measuring friction and texture are being performed on the surface of test sections twice a year at random intervals. Annual and periodical climatological data are being collected for each test section. An in-depth statistical analysis will be performed on the data in order to formulate probabilistic models for predicting seal coat friction.