Non-destructive Pavement Testing for Sustainable Road Management

Abstract

Sustainable road management asks for reliable and economic investigation methods to assess the surface and the structural substance of roads. A connection exists between properties of mixture, binder, carrots, surface texture and acoustic parameters. Noise emission and surface texture are particularly sensitive to minor variations in road engineering properties. Among the later grain size distribution is the most important quantity. Time series of drill cores, in situ surface and acoustical measurements draw a consistent picture of the process of top asphalt layer aging, including grain movements and void clogging. Georadar allows for fast microwave acquisition and mapping of electromagnetic properties as function of wave travel time. Ultrasonic measurements take more time but provide elastic parameters of road material which relate to structural substance. Measurements of mechanical road properties are sensitive to the temperature distribution inside the road body yielding temperature-dependent layer models. Depth profiles should be corrected to standard temperatures. Linear velocity-temperature relationships for ultrasonic waves yield gradients around 11 m/s/°C in a four-year old semi-dense asphalt top layer and for a temperature range between −17 and 65 ℃. Heated asphalt displays strong wave absorption particularly at high frequencies which limits penetration depths and resolution.