01337187

Component

This work evaluates the effects of conditioning time on mechanical performance of an asphalt mixture to provide recommendations on appropriate laboratory short-term conditioning time for mixture mechanical property testing. The change in flow number, minimum strain rate, dynamic modulus, flexural stiffness, and stress relaxation rate with increase in short-term conditioning time were evaluated. For samples conditioned from 0 to 6 hours, at one hour interval, the changes in mechanical properties at every possible pair of conditioning times were statistically tested. The “minimum” allowable short-term conditioning time was determined based on the time of first significant change in a property with respect to the property of an unconditioned mixture. The “maximum” allowable short-term conditioning time was determined based on the time of second significant change in a property with respect to the property of a mixture that has been conditioned for a “minimum” time. The “optimum” conditioning time for a mixture was then determined to be between “minimum” and “maximum” conditioning times. The effect of short-term conditioning on long-term performance of the mixture was used as another tool for determining the “maximum” short-term conditioning time. The results of the study indicate that the relationship between conditioning time and the mechanical properties differs from property to property, but the majority of the changes become statistically significant at conditioning times between two to four hours. Consequently, laboratory conditioning time is suggested to be limited to a period of three hours such that the changes in mechanical properties will not become significant.

01329018

11-1427

English

16p

2011

Transportation Research Board 90th Annual Meeting

DVD

Figures (6) ; References (5) ; Tables (4)

Asphalt mixtures; Dynamic modulus of elasticity; Flexural strength; Laboratory tests; Mechanical properties; Mix design; Pavement performance; Stiffness

Conditioning time; Flow number; Short term

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

Transportation Research Board Annual Meeting 2011 Paper #11-1427

TRIS, TRB

Feb 17 2011 5:48PM