Methodology for Predicting the Reflection Cracking Life of Asphalt Concrete Overlays

摘要

An experimental testing procedure has been established in the report, for quantitative analysis of overlays designed to reduce reflection cracking. From this testing procedure the overlay scheme that shows the most resistance to cracking can be chosen. The procedure uses crack propagation tests on overlay samples which are conducted on a machine called the 'overlay tester.' This machine was specifically built to stimulate the displacements resulting from temperature changes in the cracked or jointed pavement or base materials that are beneath an overlay. Various types of overlay samples were investigated on the overlay tester. These include samples with fabric, such as 'Petromat,' and samples composed of different grades of asphalt, AC-5, AC-10, and AC-20; various gradations, open graded, dense graded, and hot sand mixes; and different overlay thickness of one, two, and three inches.