01515150

Component

Moisture damage in asphalt pavements, although recognized in the early 20th century, remains a complicated issue facing pavement researchers and engineers alike. The use of additives or modifiers with asphalt mixtures is the most widely employed technique to control moisture susceptibility of asphalt mixtures. The laboratory tests applied to evaluate moisture resistance of asphalt mixtures have drawbacks, and are based on empirical procedures. In this study, the viscoelastic continuum damage (VECD) theory was used to study the susceptibility of asphalt mixtures to moisture and to evaluate the capability of anti-stripping agents to minimize damage. A moisture-susceptible asphalt mixture was treated with a liquid anti-stripping agent and hydrated lime. A traditional indirect tensile (IDT) test, a push–pull (compression–tension) test, and a complex modulus (E*) test were conducted on unconditioned and conditioned samples of treated and untreated mixtures. The conditioned samples underwent five freeze–thaw cycles. The E* and push–pull tests results showed a respective reduction in moduli and pseudo-stiffness after conditioning of the asphalt mixtures. Although the results of the push–pull test had similar trend as those of the IDT test, the results of E* were quite different. All tests indicated that liquid anti-strip is an effective additive for mitigating moisture damage. The push–pull test proved to be a promising method for evaluating the moisture damage of asphalt mixtures. It is recommended to run the push-pull test in controlled-stress mode to capture the moisture damage more effectively. The performance threshold values of the push-pull test can be better identified after conducting comprehensive laboratory tests and performing field validation using different mixtures.

This paper was sponsored by TRB committee AFK40 Characteristics of Asphalt-Aggregate Combinations to Meet Surface Requirements.

01503729

14-2925

English

17p

2014

Transportation Research Board 93rd Annual Meeting

Digital/other

Figures; Photos; References; Tables

Additives; Antistrip additives; Asphalt mixtures; Asphalt pavements; Freeze thaw tests; Laboratory tests; Moisture damage

Indirect tensile test; Viscoelastic continuum damage model

Highways; Materials; Pavements; I33: Other Materials used in Pavement Layers

Transportation Research Board Annual Meeting 2014 Paper #14-2925

TRIS, TRB, ATRI

Jan 27 2014 3:00PM