| Popis: |
Polymer-Modified Asphalt (PMA) is often applied at airports to improve the performance of Hot Mix Asphalt (HMA) pavements with respect to permanent deformation and cracking. Unfortunately, spillage of jet fuel softens the commonly used PMAs, resulting in a decrease of the integrity of the asphalt. Coal tar sealers, which are known to be carcinogenic, are often applied to prevent the jet fuel damage. The application of these sealers has two drawbacks; the seal coatings crack, which allows fuel to damage the HMA pavement and their use places carcinogenic material onto a pavement that may be recycled. In laboratory tests jet fuel resistance has been measured by loss of material from a pavement sample after 24 hours immersion in jet fuel. Requirements of a maximum one percent weight loss after 24 hour immersion have been used to qualify an asphalt as jet fuel resistant. Standard unmodified and modified asphalts fail to meet this criteria. In 1995 Ooms Avenhorn Holding, The Netherlands, developed a coal tar free, polymer-modified jet fuel resistant PMA (PMA JR) for use at the Kuala Lumpur Airport. Since that time PMA JR has been evaluated in various laboratory studies and used at airports around the world. This asphalt exhibits the excellent mechanical properties of a PMA and meets the jet fuel resistant requirement as defined by the immersion test. This material was introduced into the United States in 2002 at La Guardia Airport and in 2004 at Logan Airport. This presentation will discuss these laboratory studies as well as field experiences with this asphalt. |
