ASTM E3209/E3209M-20 PDF Download

The ASTM E3209/E3209M-20 standard provides guidance on the nondestructive measurement of pavement thickness using magnetic pulse induction (MPI) devices.

The purpose of this test method is to determine the compliance of asphalt or concrete pavement construction with thickness specifications. It offers a rapid and nondestructive means of measuring pavement thickness, providing accurate results that correlate well with direct measurement methods. The standard highlights the excellent correlation (R² values of 99.7%) between nondestructive thickness results from MPI devices and direct measurement techniques such as AASHTO T 148 and Test Method C174/C174M.

The MPI devices used in this test method are not affected by material composition, temperature, or moisture content, making them suitable for use with both concrete and asphalt pavements. This allows installers to employ quality control processes that provide reliable results for controlling the paving operation. Additionally, the method produces quantitative results that can be used to document as-built thicknesses, enabling infrastructure owners to perform quality assurance activities and accept installed facilities.

The standard details the equipment, field procedures, and interpretation of results for pavement thickness measurements using MPI devices. These devices induce a weak-pulsed magnetic field that causes the induction of eddy currents in metal objects, including pre-placed metal reflectors needed for measuring pavement thickness. The electrical signals generated when the metal reflector enters the field are processed using algorithms to detect and produce quantitative values for pavement thickness.

Furthermore, the standard provides information on the configuration and metallurgy required for purchasing and installing reflectors that ensure accurate and repeatable results. It specifies that the method is applicable to plain-jointed concrete pavements, asphalt pavements, base courses with cement binders, and unbound aggregate layers. Continuously reinforced, mesh-reinforced, or fiber-reinforced pavements with metal reinforcement that could interfere with the magnetic field are not suitable for this method.