SOLUBLE SALT DAMAGE TO THIN BITUMINOUS SURFACINGS OF ROADS AND RUNWAYS

Damage to thin bituminous surfacings of roads and runways from soluble salts has been reported in warm climates by authors from Western and South Australia, South Africa, India, North America, Middle East and more recently, North Africa, Chile and Zimbabwe. This paper introduces the physicochemical factors not previously considered essential to understanding the salt damage mechanism and reports the development and results of a laboratory testing program simulating salt damage under conditions similar to those where damage was reported in the construction of an airfield in the West Indies. These studies have introduced an improved understanding of the important relationship between salt types, migration, crystallisation, climate and construction practices. This will enhance the setting of criteria for salt damage prevention for thin bituminous surfacing. (Author/TRRL)