Sebastian Puchalski MBA MS

Softer binders have been used to compensate for the stiffness of reclaimed asphalt pavement (RAP) binders in mixtures; however, several studies have shown that asphalt rejuvenators can allow more RAP to be incorporated in mixtures than can softer binders alone. Nevertheless, rejuvenators are not specified by some state agencies because of potential rutting-related concerns. Therefore, the use of polymer modified asphalt (PMA) binder was evaluated to ascertain if it can remedy any rutting… Show more

Softer binders have been used to compensate for the stiffness of reclaimed asphalt pavement (RAP) binders in mixtures; however, several studies have shown that asphalt rejuvenators can allow more RAP to be incorporated in mixtures than can softer binders alone. Nevertheless, rejuvenators are not specified by some state agencies because of potential rutting-related concerns. Therefore, the use of polymer modified asphalt (PMA) binder was evaluated to ascertain if it can remedy any rutting performance degradation while maintaining or improving the cracking characteristics of the mixtures. The objective was to produce mixtures with high RAP content that perform similar to or better than an all-virgin-material control mixture. The effect of five asphalt rejuvenators on the performance of a 50% RAP surface-layer mixture was evaluated relative to rutting and cracking. The results illustrated that the rejuvenators degraded the rutting resistance of the 50% RAP mixture, although the use of PMA binders remedied these degradations. The rejuvenators improved the fatigue cracking resistance of the 50% RAP mixture to a level higher than did the all-virgin control mixture and also the 50% RAP mixture with softer binder alone. Overall, the data indicated that a combination of an asphalt rejuvenator and a PMA binder was required to yield a high RAP mixture with similar or better performance than a similar conventional mixture. Show less

Softer binders have been used to compensate for the stiffness of reclaimed asphalt pavement (RAP) binders in mixtures; however, several studies have shown that asphalt rejuvenators can allow more RAP to be incorporated in mixtures than softer binders alone. Nevertheless, rejuvenators are not encouraged by some state agencies because of potential rutting-related concerns. The effect of five asphalt rejuvenators on the performance of a 50% RAP surface layer mixture was evaluated in terms of… Show more

Softer binders have been used to compensate for the stiffness of reclaimed asphalt pavement (RAP) binders in mixtures; however, several studies have shown that asphalt rejuvenators can allow more RAP to be incorporated in mixtures than softer binders alone. Nevertheless, rejuvenators are not encouraged by some state agencies because of potential rutting-related concerns. The effect of five asphalt rejuvenators on the performance of a 50% RAP surface layer mixture was evaluated in terms of rutting and cracking. Furthermore, the use of Polymer Modified Asphalt (PMA) was evaluated to ascertain if it can remedy any rutting performance degradation while maintaining or improving the cracking characteristics of the mixtures. The objective was to produce mixtures with high RAP content that perform similar to or better than the all-virgin material control mixture. The results illustrated that the rejuvenators used in this study degraded the rutting resistance of the 50% RAP mixtures, but the use of the PMA binders remedied these performance degradations. The rejuvenators improved the fatigue cracking resistance of the 50% RAP mixture to a level higher than the all-virgin materials control mixture and the 50% RAP mixture with the softer binder alone. Overall, the data indicated that a combination of asphalt rejuvenators and PMA is required to yield a high RAP mixture with similar or better performance than a similar conventional mixture. Show less

Master's Thesis

The work detailed in this report represents a continuation of the research performed in phase one of this national pooled fund study. A number of significant contributions were made in phase two of this comprehensive research effort. Two fracture testing methods are proposed and specifications are developed for selecting mixtures based on fracture energy criteria. A draft SCB specification, that received approval by the ETG and has been taken to AASHTO committee of materials, is included in the… Show more

The work detailed in this report represents a continuation of the research performed in phase one of this national pooled fund study. A number of significant contributions were made in phase two of this comprehensive research effort. Two fracture testing methods are proposed and specifications are developed for selecting mixtures based on fracture energy criteria. A draft SCB specification, that received approval by the ETG and has been taken to AASHTO committee of materials, is included in the report.

In addition, alternative methods are proposed to obtain mixture creep compliance needed to calculate thermal stresses. Dilatometric measurements performed on asphalt mixtures are used to more accurately predict thermal stresses, and physical hardening effects are evaluated and an improved model is proposed to take these effects into account. In addition, two methods for obtaining asphalt binder fracture properties are summarized and discussed.

A new thermal cracking model, called "ILLI-TC," is developed and validated. This model represents a significant step forward in accurately quantifying the cracking mechanism in pavements, compared to the existing TCMODEL. A comprehensive evaluation of the cyclic behavior of asphalt mixtures is presented, that may hold the key to developing cracking resistant mixtures under multiple cycles of temperature. Show less