Quality Management of Asphalt-Concrete Layers Using Wave Propagation Techniques

摘要

Highway agencies send significant amounts of money and time coring and in-situ211u001etesting flexible pavements to implement a rigorous quality control/quality 211u001eassurance program. The quality of the asphalt concrete (AC) pavement is assessed 211u001ethrough field inspections, laboratory testing of pavement cores, thickness 211u001edeterminations, and compacted density measurements. To successfully implement a 211u001emechanistic pavement design procedure or to develop realistic performance-based 211u001especifications, a method of monitoring the modulus of a laid-down AC layer is 211u001eneeded. The modulus of an AC layer can be either indirectly predicted by using 211u001ephysical and volumetric properties of the mixture, which are measured in the 211u001elaboratory, or obtained directly from field testing. Seismic nondestructive 211u001etesting methods can potentially offer an efficient, economical, reliable, and 211u001erepeatable way of measuring the modulus of AC layers. In addition, seismic 211u001emethods are the only means of measuring the same moduli in the field and in the 211u001elaboratory. In this study, a laboratory method and a field seismic method for 211u001edetermining the modulus of AC layers are introduced, and their instrumentation 211u001eand theoretical aspects are presented. The impacts of the gradation, asphalt 211u001eviscosity (asphalt grade), void in total mix, temperature, and thickness of the 211u001eAC layer on the modulus are introduction. The preliminary protocol proposed for 211u001equality management of AC, based on seismic methods, is included.