Evaluating fatigue performance of fine aggregate matrix mixes with reclaimed asphalt pavement and rejuvenating agents

2020 ◽  
pp. 1-16
Author(s):  
Liya Jiao ◽  
Mohamed Elkashef ◽  
David Jones ◽  
John T. Harvey
Keyword(s):  
Asphalt Pavement ◽  
Fatigue Performance ◽  
Reclaimed Asphalt Pavement ◽  
Fine Aggregate ◽  
Reclaimed Asphalt ◽  
Fine Aggregate Matrix

Using Predictive Models to Estimate the Properties of Binders in Reclaimed Asphalt Pavement Mixes using Fine Aggregate Matrix Mix Testing

2019 ◽  
Vol 2673 (6) ◽  
pp. 501-511 ◽  
Author(s):  
Mohamed Elkashef ◽  
Shawn S. Hung ◽  
David Jones ◽  
John Harvey
Keyword(s):  
Predictive Models ◽  
Asphalt Concrete ◽  
Asphalt Pavement ◽  
Reliable Estimate ◽  
Reclaimed Asphalt Pavement ◽  
Fine Aggregate ◽  
Current Form ◽  
Reclaimed Asphalt ◽  
Shear Moduli ◽  
Fine Aggregate Matrix

A number of predictive models, such as the Hirsch and Al-Khateeb models, have been proposed to determine the properties of asphalt binders from asphalt concrete mix testing results. Fine aggregate matrix (FAM) mix testing can also provide useful insights into the likely performance of asphalt concrete mixes. Consequently, FAM mix testing can be an appropriate means of assessing the predictive power of these models. In this study, FAM mixes prepared with two virgin binders, PG58-28 and PG64-16, and then with different percentages of reclaimed asphalt pavement (RAP) were tested to determine their stiffness and phase angle using temperature-frequency sweeps in a dynamic shear rheometer. The data from the control mixes with no RAP were used along with the rheological properties of the virgin binders to fit the Hirsch and Al-Khateeb models. The fitted models were then used to estimate the properties of the binders in the 15% and 25% RAP FAM mixes. A comparison of the estimated binder properties with the measured binder properties clearly indicated that the fitting parameters are binder dependent. Moreover, the estimated binder moduli deviate from the measured moduli, particularly at high temperatures. The estimated complex shear moduli from the model were found to be consistently higher than the measured shear moduli values of the chemically extracted binders. It was thus concluded that the predictive models studied, in their current form, fail to provide a reliable estimate of the binder properties in mixes containing RAP.

Influence of Reclaimed Asphalt Pavement on Performance-Related Properties of Gap-Graded Rubberized Hot-Mix Asphalt

2017 ◽  
Vol 2633 (1) ◽  
pp. 80-89 ◽  
Author(s):  
Shawn S. Hung ◽  
Mohammad Zia Alavi ◽  
David Jones ◽  
John T. Harvey
Keyword(s):  
Performance Test ◽  
Hot Mix Asphalt ◽  
Asphalt Pavement ◽  
Environmental Benefits ◽  
Reclaimed Asphalt Pavement ◽  
Fine Aggregate ◽  
Reflective Cracking ◽  
Cracking Resistance ◽  
California Department ◽  
Reclaimed Asphalt

Rubberized hot-mix asphalt (RHMA) has been widely used in construction projects by the California Department of Transportation (Caltrans) for the environmental benefits of its recycled waste tires and for its improved fatigue and reflective cracking resistance. Currently, Caltrans does not permit the use of reclaimed asphalt pavement (RAP) in any gap- or open-graded rubberized asphalt mixes. However, given the cost and environmental benefits of RAP to replace portions of required virgin binder and aggregates in conventional mixes, interest is growing in the addition of some RAP to RHMA mixes as well. This study investigated concerns about this proposed practice. Three phases of laboratory testing (i.e., asphalt binder testing, fine aggregate matrix mix testing, and full-graded mix testing) were conducted to evaluate the effects of the addition of RAP into new RHMA mixes. The results indicated that the gap-graded aggregate structure of RHMA might limit the amount of RAP that could be used in the mix. Only 10% RAP by binder replacement could be achieved for the mix tested in this study, but the other specified volumetric requirements were still met. Replacement of a portion of asphalt rubber binder with age-hardened RAP binder increased the binder stiffness at low and high temperatures, which indicated enhanced rutting performance but diminished low-temperature cracking performance. Test results from full-graded mixes indicated similar trends, with improved rutting performance with the addition of RAP but also with significantly poorer fatigue and reflective cracking resistance.

Georgia’s Experience with Recycled Roofing Shingles in Asphaltic Concrete

1998 ◽  
Vol 1638 (1) ◽  
pp. 129-133 ◽  
Author(s):  
Donald E. Watson ◽  
Andrew Johnson ◽  
Hem R. Sharma
Keyword(s):  
Test Section ◽  
Building Materials ◽  
Asphalt Pavement ◽  
Cost Savings ◽  
Reclaimed Asphalt Pavement ◽  
Fine Aggregate ◽  
Asphaltic Concrete ◽  
Department Of Transportation ◽  
Reclaimed Asphalt ◽  
Asphalt Cement

Reuse of roofing shingle waste not only minimizes the environmental problems related to the disposal of waste in landfills, but also reduces the amount of virgin asphalt cement and fine aggregate required in hot mix asphaltic concrete (HMAC), thus creating the potential for cost savings. The Georgia Department of Transportation (GDOT) has experimented with the recycling of roofing shingles in HMAC by constructing two test sections in 1994 and 1995. The source of the roofing shingles used in both test sections was waste generated by a roofing manufacturer; this generally consisted of discolored or damaged shingles. One test section was constructed on Chatham Parkway in Chatham County and one on State Route 21 in Effingham County. GAF Building Materials, Inc., located in Savannah, provided the waste shingle material; APAC Georgia, Inc., also located in Savannah, produced and placed these experimental mixtures. To date, both test sections are performing well compared with the unmodified control sections. Based on the performance of these test sections, shingle manufacturing waste is allowed as a recycling material in HMAC, just as reclaimed asphalt pavement is, for GDOT projects. A specification allowing postconsumer roofing shingle waste to be used is also being proposed.

scholarly journals Rutting and moisture-induced damage potential of foamed warm mix asphalt (WMA) containing RAP

2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Mohammad Ashiqur Rahman ◽  
Rouzbeh Ghabchi ◽  
Musharraf Zaman ◽  
Syed Ashik Ali
Keyword(s):  
Asphalt Pavement ◽  
Warm Mix Asphalt ◽  
Environmental Benefits ◽  
Reclaimed Asphalt Pavement ◽  
Chemical Additives ◽  
Flow Number ◽  
Damage Potential ◽  
Asphalt Mixes ◽  
Reclaimed Asphalt ◽  
Wheel Tracking

AbstractDespite significant economic and environmental benefits, performance of warm mix asphalt (WMA) containing reclaimed asphalt pavement (RAP) remains a matter of concern. Among the current WMA technologies, the plant foaming technique (called “foamed WMA” in this study) has gained the most attention, since it eliminates the need for chemical additives. In the present study, the laboratory performance, namely rutting and moisture-induced damage potential of foamed WMA containing RAP were evaluated and compared with those of similar hot mix asphalt (HMA) containing identical amount of RAP. Dynamic modulus, Hamburg wheel tracking (HWT) and flow number tests were performed to assess the rutting resistance of the mixes. Also, stripping inflection point from HWT tests and tensile strength ratio after AASHTO T 283 and moisture induced sensitivity test (MIST) conditioning were used to evaluate the moisture-induced damage of asphalt mixes. It was found that MIST conditioning effectively simulates the moisture-induced damage and can capture the propensity of asphalt mixes to moisture damage more distinctly compared to AASHTO T 283 method due to application of cyclic loadings. The foamed WMA was found to exhibit higher rutting and moisture-induced damage potential due to lower mixing and compaction temperatures compared to HMA. However, the increase in RAP content was found to reduce rutting and moisture-induced damage potential for WMA. Therefore, the lower stiffness of foamed WMA may be compensated with the addition of stiffer binder from RAP.

Sign in / Sign up

Export Citation Format

Share Document