ABSTRACT
The Seismic Pavement Analyzer (patent pending) is a new nondestructive testing device that can help the maintenance and design engineers in pavement evaluation. The device was developed under the Strategic Highway Research Program.
Several seismic testing techniques are combined: 1) Ultrasonic Body Wave, 2) Ultrasonic Surface Wave, 3) Impulse Response, 4) Spectral Analysis of Surface Waves (SASW), and 5) Impact Echo. With these methods eight pavement parameters are measured (including moduli of each layer). The operation of the system has been automated to make it quite simple. Most of the data reduction is done rapidly in the field, and the results are saved in a database for later analysis.
A portable version of the SPA has also been developed. The main tests used are: the Impact Echo for finding the thickness of the slab, the Ultrasonic Body Wave for estimating the modulus, and the Ultrasonic Surface Wave for also detecting the modulus. The device is attractive for detecting the onset of delamination of slabs and bridge decks, and quality control of pavement layers.
Extensive field testing on many types of base and subgrade, and bridge decks, the techniques document the suitability of the two devices, and the techniques in general, for many quality control and diagnostic projects.
