The indirect tensile test on asphalt concrete mixes is a frequently used procedure for assessing likely pavement performance. Currently, the indirect tensile test is most commonly used for providing information on moisture susceptibility. However, the indirect tensiletest may also be used to determine engineering properties needed for elastic and viscoelastic analyses and for evaluating thermal cracking, fatigue cracking, and potential problems with tenderness. Giventhe importance of this test, there appears to be a lack of information on the factors that determine indirect tensile strength (idts) of asphalt mixes. Consequently, the effects of asphalt composition and physical properties on idts values were obtained. Mixes were made with 15 different types of asphalt and with 2 different types of aggregate (traprock and gravel). Asphalt composition was characterized by gel permeation chromatographic analysis. The penetration of the thin-film oven test residue and idts values were strongly correlated.The idts values increase as penetration decreases. Asphalt composition also plays a significant role in determining the idts values of traprock mixes. Asphalt composition seems to account for differencesof up to 55% in idts values of traprock mixes. However, the effect of asphalt composition on gravel mixes appears to be much less pronounced. This paper appears in transportation research record no. 1269, Asphalt mix materials and mixtures 1990.
Abstract