Overview The flexural fatigue test is used to characterize the fatigue life of HMA at intermediate pavement operating temperatures. This characterization is useful because it provides estimates of HMA pavement layer fatigue life under repeated traffic loading. In a well designed pavement, strains in the pavement are low enough so that fatigue is not a problem. However, when pavements are under-designed strains are sufficiently high to cause fatigue failures under repeated loads. These failures ultimately result in fatigue cracking which will cause disintegration of the pavement if not maintained in time.

Accelerated pavement testing (APT) refers to “the controlled application of a prototype wheel loading, at or above the appropriate legal load limit to a prototype or actual, layered, structural pavement system to determine pavement response and performance under a controlled, accelerated accumulation of damage in a compressed time period” (Metcalf, 1996[1]). Typically APT involves (1) a specially designed test track like those at Mn/ROAD, WesTrack and NCAT where actual trucks are driven across prepared pavement sections, or (2) a specially designed loading mechanism that can provide simulated loads on an existing or specially built pavement section such as Caltrans’ heavy vehicle simulator.

HVSIA definition and history Although Accelerated Pavement Testing (APT) is generally recognized as one of the most effective methods of evaluating improvements in pavement design and performance, it is expensive relative to other, typical pavement research activities. As a result, collaboration between APT programs, as well as other research efforts, is often discussed as a potential to improve the efficiency of APT research. The Heavy Vehicle Simulator International Alliance

HVS stands for Heavy Vehicle Simulator. It’s a large piece of equipment that allows for repeated passage of a truck or aircraft wheel over a pavement, simulating the action of many of such wheels from heavy vehicles. It is used in research to test pavement structures and roadway elements and their response to traffic.