Mechanistic Analysis and Economic Benefits of Fiber-Reinforced Asphalt Overlay Mixtures

Abstract

Among the various distresses in flexible pavement structures, rutting and fatigue cracking can be accounted as two of the major distresses that need to be addressed by pavement engineers. Laboratory tests, such as four-point bending beam and flow number are utilized to characterize the rutting and cracking resistance of flexible pavements. Various construction practices are introduced to reduce the effect of fatigue and rutting in pavement structures. One of such methods is applying fibers to the asphalt mixture to prolong the serviceability and the performance of the pavement structures. The use of fibers is applicable to freshly constructed pavements as well as in the pavement rehabilitation and maintenance work, such as overlay. This paper primarily analyses the application of fibers in the overlay of pavements. The two major cases of the pavement with original asphalt overlay and the one with fibers mixed asphalt overlay is considered utilizing a developed testing program where the mechanistic analysis as well as the economic effectiveness is evaluated. 3D move analysis software package is utilized extensively as a means of mechanistic analysis tool. It is found that the fiber mixture pavement overlay had a higher pavement life than the ordinary asphalt overlay. In addition, the cost effectiveness in terms of fatigue and rutting of fiber-reinforced overlay structures were 4.4 and 4.1 times the unmodified mixtures, respectively. The use of fibers in the overlay of pavement resulted in higher pavement life with a high cost effectiveness.

Keywords

• mechanistic analysis
• overlay
• fatigue cracking
• rutting
• fatigue life
• rutting life
• cost-effectiveness