Fog and rejuvenator sealers are the lowest cost preventive maintenance treatments. This study addressed the question, "Are they effective and safe?" A survey of States and industry experts preceded field trials evaluating a number of products on different surface types with different climates and traffic levels. Several test methods, including permeability, friction, surface texture, spectral wave analysis, and chemical and rheological properties of extracted cores and core slices over a period of six years were evaluated. It was found that the seals are generally inexpensive and effective in providing sealing protection to pavement surfaces and prolonging pavement life. The primary constraint to the use of sealers on dense-graded surfaces is friction loss. Sanding and strict traffic control until friction returns to a specified level can mitigate the problem. The easily portable Dynamic Friction Tester and Circular Texture Meters are useful devices for quick and repeatable field friction testing. A relatively inexpensive low temperature measure of m-value on thin core slices using the Bending Beam Rheometer is an intriguing tool for determining the brittleness of aging dense pavement surfaces. Other test methods gave mixed results. Visual observations showed the seals were still preventing surface water intrusion as long as four years after treatment. Sealers can also significantly prolong the life of seal coats, open-graded mixes and shoulders, where concerns with friction loss are considerably fewer.
Abstract