The quality of the material selected and used as a base for road construction can have a significant impact on the long-term performance of flexible pavements. Research has shown that many forms of pavement distress, including rutting, can be linked to the base material. In order to better understand the influence of the base in the rutting experienced in a pavement, laboratory and small-scale tests were performed on three base materials commonly used in Texas. Triaxial tests, permanent deformation tests and the resilient modulus tests were performed at different states of stress and moisture conditions. The results were then used with VESYS to predict the contribution of the base to the overall rut of a pavement. The rutting patterns from this exercise were then compared to the permanent deformations measured under repeated load using small-scale specimens at various moisture levels. Several of the laboratory test methods, especially the permanent deformation tests, can rank the potential for rutting; however, the magnitude of rutting predicted from the analytical models did not favorably match those from the small-scale tests.
Abstract