Fatigue and stiffness properties of roadbase layer using indirect tensile test. Paper prepared for presentation at the Eurasphalt & Eurobitume Congress, Strasbourg, 1996.

Quality control and evaluation of bituminous pavement layers often have to be performed by highway engineers. In many cases, determination of the mix composition is insufficient for an evaluation of the mix properties. However, mechanical properties such as fatigue strength and stiffness modulus can provide much applicable information. The mechanical properties of bituminous mixes can be determined by various methods, but these require special equipment and specimens of a particular configuration. Asphalt specimens are relatively easy to fabricate in the laboratory, but they are very difficult or even impossible to obtain from existing bituminous layers. In this work, the stiffness modulus and fatigue properties of different types of bituminous pavement layers have been determined in the laboratory. Indirect tensile test (ITT) has been conducted primarily due to its advantages in practice. It has the benefit of using cylindrical specimens which can be cored from pavement layers. It is concluded that the ITT, which is relatively simple and rapid to conduct, is also sufficiently accurate for routine measurements. (A) For the covering abstract of the Eurasphalt & Eurobitume Congress, Strasbourg, 1996, see IRRD 885061.