A field study conducted at the Pavement Durability Research Facility of the Pennsylvania Transportation Institute and on Pennsylvania Route 64 to determine the effect of specific construction, traffic, and materials variables on the performance of bituminous seal coats is described. The condition of the existing surface (worn or levelled), emulsion application rate, rolling patterns, time between construction operations and opening to traffic, and polymer modification were among the study variables. Accelerated traffic was applied to the sections for 1 year, and the performance, skid resistance, visual evaluations, and mean texture depth were documented. Design and construction variables were found to diminish the other study variables. Conclusions are presented that relate to the different phases of a seal-coat operation, including surface preparation, materials selection and specification, seal-coat design, construction procedures, and quality control.
Abstract