One of the major research goals of the Strategic Highway Research Program is to develop a relationship between asphalt binder properties and field performance for asphalt concrete mixtures. A part of this effort is concerned with development of a system and procedure to moisture-condition asphalt concrete specimens to determine whether an asphalt-aggregate mixture is susceptible to moisture-induced damage. The development of a computer-controlled loading and data acquisition subsystem used with moisture conditioning and environmental control subsystems is addressed. The three subsystems make up a state-of-the-art test system that is used to determine and measure the factors that most influence the amount of moisture damage. A brief overview of the three subsystems is given, as is a more detailed description of the development and evaluation of pertinent test parameters. Significant findings include: (a) many factors affect the reliability of subsystems, and the computer-controlled loading and data acquisition subsystem provides an efficient tool for detecting factors causing variability in test results; (b) specimen instrumentation is simple, reliable, and accurate; (c) specimens 4in high and 4in in diameter were found to provide results of sufficient accuracy; and (d) specimen orientation was found to be very important. (Author/publisher)
Abstract