Performance characteristics of plant produced high RAP mixtures

Mogawer, Walaa S.; Bennert, Thomas; Daniel, Jo Sias; Bonaquist, Ramon; Austerman, Alexander J; Booshehrian, Abbas

doi:10.1080/14680629.2012.657070

Cited by 250 publications

(139 citation statements)

References 3 publications

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“…processing as well as introduction of bio-binder to enhance workability (Mogawer et al, 2012). Grinding to ultra-fine particle size and blending with asphalt binder through a wet process has been reported to be effective in facilitating application of high percentage of RAS (Elseifi et al, 2012).…”

Section: Ajeasmentioning

confidence: 99%

Investigating Effects of Amine Based Modifier on Recycled Asphalt Shingles Blending

Sedhay¹

2014

American Journal of Engineering and Applied Sciences

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A laboratory study was conducted to investigate the effects of Amine based modifier on rheological characteristics of particle filled viscous medium such as asphalt binder in presence of Recycled Asphalt Shingles (RAS). In this study, virgin asphalt binder , three different percentages (20, 30 and 40%) of tear-off shingles and modifiers; Rediset, Evotherm and Bio-binder were used. The tear-off shingles acquired from local reroofing company in Greensboro, North Carolina; were finely grinded (85% passing of sieve # 200). The virgin binder and different percentages of RAS were then blended at 180°C using shearing speed of 400 rpm. Following that themixture was blended with 1.5% of Rediset, 0.5% of Evotherm and 5% of bio-binder. The properties of the blended binder were studied using the Rotational Viscometer (RV) equipped with two different spindle types:-One was Smooth Cylindrical spindle (SC4-27D) and the other one was Vane spindle (V 73). The analysis showed that the viscosity was increased with increasing the RAS percentage. Furthermore, the viscosity measured by vane spindle was continuously higher than the value measured by smooth spindle; however the difference between the two measurements reduced as the blending were improved using modifiers. Moreover, temperature found to be the main contributor to reduction of the viscosity in both spindles cases. In addition the coefficient of variation was significantly lower in the case of vane spindle, indicating that the vane spindle could be more appropriate in measuring viscosity of particle filled viscous medium such as RAS asphalt. Based on the experimental result an empirical index called blending index was introduced in this study to measure the blending behavior and status for modified mixtures. As expected it was found that the blending index increases as the temperature and rotational speed increases. In other word, higher temperature and shearing rate could enhance blending resulting in higher blending index. The blending index was further used as a laboratory measure to compare effectiveness of various additives in enhancing blending of RAS modified mixtures. It was shown that among three modifiers used in this study, the bio-binder was more effective to increase the blending index.

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Section: Ajeasmentioning

confidence: 99%

Investigating Effects of Amine Based Modifier on Recycled Asphalt Shingles Blending

Sedhay¹

2014

American Journal of Engineering and Applied Sciences

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“…A counterflow dryer with an outer aggregate blending chamber, like the double RAP dryer, is the best option for batch plants producing high RAP content mixes [40]. Use of High RAP proportion reduces the workability and increases the compactibility requirement of the mix due to stiff aged binder associated with RAP [41,42]. This problem can be addressed by softer bitumen, the addition of rejuvenator and use of WMA additives [43,44].…”

Section: Use Of Rap In Hmamentioning

confidence: 99%

Use of reclaimed asphalt pavement (RAP) in warm mix asphalt (WMA) pavements: a review

Farooq

Mir

2017

Innov. Infrastruct. Solut.

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The limit in the use of reclaimed asphalt pavement material (RAP) proportion is restricted due to stiffness and workability issues related to RAP. This problem is addressed with the help of warm mix asphalt (WMA) which increases the proportion of RAP used by producing mixes having same/better properties viz., better workability, reduced viscosity than hot mix asphalt (HMA) at lower temperatures. This paper reviews research conducted on the use of RAP material in WMA pavements. It presents and discusses work done with regard to different recycling methods and on conversion of RAP into HMA. It analyzes the benefits/need of using RAP in WMA in light of previous research findings and the influence on engineering properties of WMA due to RAP introduction. This paper also discusses field performance, environmental/economic impact and some limitations of these mixes.

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“…Undoubtedly, these factors make this practice a valuable alternative for the construction of road infrastructure projects. Typical values of RAP allowed in the fabrication of new asphalt mixtures are in a range of 10 to 20% (Mogawer et al, 2012). However, concerns related to the contribution of the hardened bitumen from RAP in the final mixture performance and durability in the field have limited the production of new HMA with higher amounts of this material.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, another concern related with the use of RAP materials is associated with the interaction between the aged bitumen present in the RAP and the virgin bitumen. A number of studies related to this concern have been conducted (Copeland, 2011;Huang, Li, Vukosavljevic, Shu, & Egan, 2005;Mogawer et al, 2012), which have mainly focused on determining the level of blending between old-new bitumen and how this process, along with the amount of RAP introduced, affects the performance of the mixture. However, there are other issues related with this interaction of old-new materials that still remain unsolved and play a significant role in the performance of the final mixtures.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the degradation of fine asphalt-aggregate mixtures containing high reclaimed asphalt pavement contents

Sánchez

Grenfell

Airey

et al. 2017

Road Materials and Pavement Design

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This paper evaluates the mechanical properties and performance of the Fine Aggregate Matrix (FAM) existing within full RAP asphalt mixtures, in terms of their rheological and fatigue deterioration properties. The RAP material was produced in the laboratory to control its properties and to reduce the effects of variability associated with these materials. Four FAM mixtures were analysed, including a virgin HMA, a 100%RAP and two mixtures containing 50% RAP in combination with virgin materials using different penetration grade virgin binders.The analysis of the deterioration properties was based on the application of a fracture model that incorporates the viscoelastic properties of the material, the quality of the adhesive bonds developed between the aggregates and the corresponding bitumen present in each mixture, and the rate at which the material dissipates energy when subjected to cycling loading. The input parameters for this model include the results obtained from Dynamic Mechanical Analysis (DMA) and Surface Free Energy (SFE) tests. In general, the results showed that the incorporation of 50%RAP content increased the stiffness of the final mixtures, as expected. However, this hardening effect did not result in mixtures with inferior fatigue performance of the FAM present in the full mixtures, at the applied strain level.

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Performance characteristics of plant produced high RAP mixtures

Cited by 250 publications

References 3 publications

Investigating Effects of Amine Based Modifier on Recycled Asphalt Shingles Blending

Investigating Effects of Amine Based Modifier on Recycled Asphalt Shingles Blending

Use of reclaimed asphalt pavement (RAP) in warm mix asphalt (WMA) pavements: a review

Evaluation of the degradation of fine asphalt-aggregate mixtures containing high reclaimed asphalt pavement contents

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