scholarly journals Study on the Suitability of Reclaimed Asphalt Pavement Aggregate (RAPA) in Hot Mix Asphalt Production

Author(s):  
Tiruwork Mulatu ◽  
◽  
Biruk Yigezu ◽  
Anteneh Geremew ◽  
◽  
...  

The main objective of this study was to evaluate the suitability of recycled asphalt aggregate with fresh aggregate in hot mix asphalt production by using experimental laboratory investigation. Also, Non-probable sampling techniques were adopted to collect a sample. The engineering properties of extracted Reclaimed asphalt pavement aggregate and the fresh crushed aggregate were identified based on standard specification before starting the Marshall Mix design, Then the Marshall Stability test was conducted on crushed aggregate with three different aggregate gradation sizes 5.0%, 5.5% and 6.0% by weight of aggregates and with five different bitumen content 4.0%, 4.5%, 5.0%, 5.5% and 6.0% by weight of total mix. Depending on the selected aggregate gradation Marshall Stability test was conducted for reclaimed asphalt pavement aggregate with a replacement rate of 5.0%, 15%, 25%, 35%, 45%, 55%, and 65% by weight of crushed aggregate to determine its optimum bitumen content according to National Asphalt Pavement Association method (NAPAM). A total of 64 mix designs and 190 specimens were prepared. Hence, Marshall Stability and Moisture Susceptibility test with 3-trials, hence rutting test with 2-trials. From 190 specimens, 45 were for the control mix, 105 were for replacement proportion, 36 were for Moisture Susceptibility and 4 were for Rutting Based on the Marshall Test results and their performance tests such as Moisture Susceptibility and Rutting was performed to maximum allowable replacement percentage was compared with standard specification. The optimum bitumen content result obtained in percent was 5.1, 5.04, 4.98, 4.87, 4.81, 4.74, 4.67 and 4.53 for 0 % (control), 5.0%, 15%, 25%, 35%, 45%, 55% and 65%, respectively. The experimental value of Tensile Strength Ratio, proportional rut depth and mean rut depth on 45% RAPA replacement was 85.42% and 4.48 %, 2.24 mm respectively. Finally, the test result obtained from the marshal stability and the performance testes indicates that up to 45% replacement of aggregate is reclaimed asphalt pavement aggregate in hot mix asphalt production satisfies the standard specification.

Author(s):  
Milad Zokaei Ashtiani

This study is an attempt to create a framework, using the best available inventory data, to perform lifecycle assessment (LCA) on asphalt pavement production. In particular, the use of reclaimed asphalt pavement (RAP) as an end-of-life product of deteriorated pavements is under consideration. Following ISO 14000 series standards, the framework constitutes the four major LCA steps in defining goal and scope, lifecycle inventory analysis, environmental impact assessment, and results interpretation. Three different scenarios in which varying portions of RAP are incorporated into hot mix asphalt production are to be compared. The system boundary of this study is limited to the construction and rehabilitation phases and ignores the vehicular use phase. It was found under this study that since high RAP mixtures require more frequent and aggressive maintenance activities, the overall footprint of asphalt pavements constructed with higher RAP contents is also higher. This would necessitate more efficient design procedures and protocols for mixtures produced with high RAP contents to compensate for their lack of long-term performance.


Author(s):  
Ram Kumar Veeraragavan ◽  
Rajib B. Mallick ◽  
Mingjiang Tao ◽  
Martins Zaumanis ◽  
Robert Frank ◽  
...  

The Maine Department of Transportation (DOT) currently allows 20% reclaimed asphalt pavement (RAP) in base and intermediate courses. To help the Maine DOT decide whether RAP could be increased to 50%, this study evaluated the critical laboratory properties of hot-mix asphalt with 50% RAP materials and rejuvenator. The scope of work consisted of preparing 20% and 50% RAP mixes with and without rejuvenators and testing compacted specimens for their volumetric properties, moduli, indirect tensile strength, moisture susceptibility, and low- and intermediate-temperature cracking potential. Two rejuvenators were used: ( a) generic waste vegetable oil and ( b) proprietary, commercially available rejuvenator. Virgin binder, extracted RAP binder, and extracted binder from recycled mixes were tested for continuous performance grading. The results showed that rejuvenators improved the properties of high RAP mixes, and the performance of rejuvenated 50% RAP mixes was equal to that of the currently allowed 20% RAP mixes. Results from semicircular bending tests were used to evaluate and quantify the effect of rejuvenators on mixes with high RAP content. Field trials of 50% RAP mixes were recommended as a result of the study.


Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2536 ◽  
Author(s):  
Sen Han ◽  
Xianpeng Cheng ◽  
Yamin Liu ◽  
Yacai Zhang

Recently, there has been an increasing interest in the applications of recycled mixtures with a high reclaimed asphalt pavement (RAP) content. However, many government departments are hesitant about the applications of that due to being worried about the durability of its pavement, and few findings has been reported in terms of the percentage of fine reclaimed asphalt pavement (FRAP, 0~5 mm) in recycled mixtures. In this paper, 25% or more RAP by the weight of aggregates is defined as high RAP and high FRAP refers to 10% or more FRAP by the weight of aggregates. This paper examines the laboratory performances of mixtures with high RAP (30%, 40%, and 50%) and FRAP (10%, 15%, and 20%). Performance evaluations have been conducted by conventional tests, including the low-temperature bending test, fatigue test, and the moisture susceptibility test. The results show that with the increasing RAP and FARP contents, 41% (30-R-10) to 63% (50-R-15) of virgin asphalt can be saved, both the low-temperature and fatigue performance decrease, and the moisture performance firstly increases and then decreases. The results of analysis of variance (ANOVA) in terms of low-temperature and moisture performance show that RAP contents in recycled mixtures have a significant effect on the performance, while the effect of FRAP contents on the performance of recycled mixtures is insignificant.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Anni Susilowati ◽  
Andhika Kesuma

ABSTRACTReclaimed Asphalt Pavement (RAP) material as a result of road maintenance by Scrapping-Filling-Overlay method is a waste material which had potential to be recovered as a surface layerof road. The maintenance in highway road of Indonesia used hot mix asphalt in general. But, hot mix asphalt are not environmentally friendly and makes energy wasting because it needs burning process at mixing. Those things are the main causes of this research. This asphalt concrete with RAP with cold mixing is expected to fulfill the requirements of asphalt concrete for heavy traffic. In this research is asphalt content variations at 6,5; 7,0; 7,5; 8,0; and 8,5% to total mixture. The results of this research shows that the highest Marshall stability could not reach minimum value of heavy loaded traffic, that is at emulsion asphalt content 7% only for 711 kg. Besides, the percentage of void in mixture (VIM), void filled with bitumen (VFB) and flow couldn’t fulfill the specification of SNI 8198:2015. With the result that optimum asphalt content cannot be obtained. Result of wheel tracking test could not be obtained too because the specimens collapse during the test.Key words : Emulsion asphalt, Reclaimed Asphalt Pavement, stability, Wheel Tracking MachineABSTRAKMaterial Reclaimed Asphalt Pavement (RAP) hasil dari pemeliharaan dengan metode Scrapping-Filling Overlay merupakan limbah yang berpotensi untuk dimanfaatkan kembali menjadi lapis permukaan. Pada umumnya penanganan jalan di Indonesia menggunakan campuran panas. Namun, campuran panas kurang ramah lingkungan dan tidak hemat energi. Karena membutuhkan proses pembakaran dalam proses pencampuran. Hal ini yang menjadi alasan utama penelitian ini. Beton aspal dengan bahan utama RAP dengan campuran dingin ini diharapkan mampu memenuhi syarat lapisan aspal beton untuk lalu lintas berat. Variasi pada penelitian ini adalah kadar aspal 6,5; 7,0; 7,5; 8,0; dan 8,5% terhadap total campuran. Hasil dari penelitian menunjukan bahwa stabilitas Marshall tertinggi tidak mampu mencapai nilai minimum untuk lalu lintas berat, yaitu pada kadar aspal emulsi 7% hanya sebesar 711 kg. Selain itu prosentase rongga dalam campuran (VIM), rongga terisi aspal (VFB) serta kelelehan tidak memenuhi spesifikasi dari SNI 8198:2015. Sehingga, kadar aspal optimum tidak didapatkan. Hasil dari pengujian alur roda juga tidak didapatkan karena benda uji amblas ketika pengujian dilakukan.Kata kunci : Aspal emulsi, Reclaimed Asphalt Pavement, stabilitas, Wheel Tracking Machine


Author(s):  
Edith Arámbula-Mercado ◽  
Santiago J. Chavarro-Muñoz ◽  
Sheng Hu ◽  
Howie Moseley

Florida Department of Transportation yearly maintenance and rehabilitation activities include milling and resurfacing of approximately 2,000 lane miles of roadway, with an average resurfacing depth of about 2.1 in. (55 mm). These activities result in the generation and accumulation of roughly 1.8 million tons of reclaimed asphalt pavement (RAP) each year. The use of elevated quantities of RAP in asphalt pavement provides an environmentally responsible solution to the accumulated RAP surplus in some urban areas, while at the same time offering an economical pavement maintenance and rehabilitation option to local agencies facing budget constraints. The objective of this project was to compare the performance of mixtures with 60% RAP content to be used primarily on low volume roads (average daily traffic <750 vehicles) and suggest adequate test methods within the context of a balanced mix design approach. To accomplish this objective, three types of mixtures were considered: hot, cold with emulsion, and cold with foamed binder. Performance testing included intermediate temperature cracking, rutting, moisture susceptibility, and durability. The hot recycled mixtures showed good moisture susceptibility and cracking resistance, especially when rejuvenators were incorporated. The cold recycled mixtures showed poor moisture susceptibility and durability characteristics, which were alleviated when hydrated lime or Portland cement was incorporated in the emulsified and foamed mixtures, respectively. Most hot recycled mixtures, and all the cold recycled mixtures, exhibited poor rutting behavior, likely because of the harsh conditions of the test. A life-cycle cost analysis demonstrated more favorable savings when cold recycled mixtures were used.


Author(s):  
Walaa S. Mogawer ◽  
Alexander J. Austerman ◽  
Robert Kluttz ◽  
Michael Roussel

A high-performance thin asphalt overlay (HPThinOL) is specified as having a thickness of 1 in. or less and is used in applications requiring high levels of rutting and fatigue resistance. HPThinOLs are used as a pavement preservation strategy and are placed on pavements that have remaining structural capacity that is expected to outlive that strategy. Current specifications for HPThinOLs generally call for a polymer-modified asphalt (PMA). However, PMA binders are more expensive than unmodified asphalt binders. This expense, coupled with the higher binder content requirement generally associated with HPThinOL, could lead to an initial higher cost in relation to other pavement preservation strategies. Although the higher initial cost can be offset by incorporating high amounts of reclaimed asphalt pavement (RAP), the use of high amounts of RAP in PMA mixtures might adversely affect the mixture performance (stiffness, cracking, or workability). Warm-mix asphalt (WMA) technology may improve the workability of HPThinOL that incorporates high RAP content and PMA binders. This study evaluated the effect of PMA binders, high RAP content, and WMA technology on the stiffness, resistance to reflective cracking, moisture susceptibility, and workability of HPThinOL mixtures. PMA binders and high RAP content increased the stiffness of HPThinOL significantly; however, the use of WMA technology lowered mixture stiffness and improved workability. PMA may improve the cracking resistance, moisture susceptibility, and rutting resistance of high-RAP HPThinOL mixtures, depending on whether a WMA technology is used.


2011 ◽  
Vol 39 (1) ◽  
pp. 102699 ◽  
Author(s):  
M. R. Mitchell ◽  
R. E. Link ◽  
Feipeng Xiao ◽  
Serji N. Amirkhanian ◽  
Boli Wu

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