Aggregate Base Course : Flexible pavement consists of two layers. The top layer is usually a bituminous surface, and the bottom layer consists of gravel or crushed stone base course
Ilan Kelman (ed.), Vulnerability and Resilience Definitions and References, Version 2, 2007. http://www.islandvulnerability.org/docs/vulnres.pd f, (Vulnr and Resilience - Brit) {524}