ASTM D4748-10(2020)

6.1 This test method permits accurate and nondestructive thickness determination of bound pavement layers. As such, this test method is widely applicable as a pavement system-assessment technique.

6.2 Although this test method, under the right conditions, can be highly accurate as a layer-thickness indicator, consistently reliable interpretation of the received radar signal to determine layer thicknesses can be performed only by an experienced data analyst. Such experience can be gained through use of the system and through training courses supplied by various equipment manufacturers or consulting companies. Alternatively, the operator may wish to use computer software to automatically track the layer boundaries and layer thickness, where applicable.

1.1 This test method covers the nondestructive determination of the thickness of bound pavement layers using ground penetrating radar (GPR).

1.2 This test method may not be suitable for application to pavements which exhibit increased conductivity due to the increased attenuation of the electromagnetic signal. Examples of scenarios which may cause this are: extremely moist or wet (saturated) pavements if free electrolytes are present and slag aggregate with high iron content.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.