PREVENTION OF SALT DAMAGE TO THIN BITUMINOUS SURFACINGS: DESIGN GUIDELINES

A design method to prevent soluble salt damage to thin bituminous road and runway surfacings based on laboratory tests and field trials is proposed. Remedial treatments for damaged surfacings are also suggested. The damage, characteristic of warm islands and arid and semiarid inland regions of the world, occurs when salts crystallize in the pavement, physically disrupting the bituminous surfacing and causing premature deterioration of the road. Bituminous primes have been found to be more susceptible to damage than final surface dressings. The design method has been developed from laboratory studies in the United Kingdom and field trials in the West Indies and Botswana. They apply wherever a waterbound or a chemically stabilized pavement layer is covered with a thin bituminous surfacing.