scholarly journals Mechanical performance assessment of half warm recycled asphalt mixes containing up to 100 % RAP

2017 ◽  
Vol 7 (080) ◽  
pp. 129 ◽  
Author(s):  
J. M. Lizárraga ◽  
A. Jiménez del Barco-Carrión ◽  
A. Ramírez ◽  
P. Díaz ◽  
F. Moreno-Navarro ◽  
...  

The use of Half Warm Mixes with high Reclaimed Asphalt content (HWMRA) has the potential to generate significant environmental advantages such as the reduction in consumption of natural resources and the emission of gases into the atmosphere. This paper therefore focuses on demonstrating the viability of using these types of mixes in wearing courses. For this purpose, an HWMRA with 70 % and 100 % Reclaimed Asphalt Pavement (RAP) and emulsion were designed in the laboratory. The performance of the mixes was then assessed and compared with that of conventional Hot Mix Asphalt. In a second stage, the mixes were manufactured in-plant, and laid and compacted in an Accelerated Pavement Test track. The cores were then extracted and tested for stiffness modulus and resistance to fatigue. The results from the tests conducted with both the laboratory specimens and the cores showed that the performance of HWMRA is comparable to that of HMA. These findings encourage greater confidence in promoting the use of these types of sustainable asphalt mixes.

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4986
Author(s):  
Jaroslav Pokorný ◽  
Radek Ševčík ◽  
Jiří Šál

Reclaimed asphalt pavement (RAP) is a valuable commodity originating during processes of road/highways rehabilitations, resurfacing in the cases of the revelation of underneath-placed layers. Removed material can be successfully recycled and utilized as a supplementing material for new hot asphalt mixes. However, its dosages are limited because of variations in properties of aged bitumen compared to fresh material and, thus, a significant amount of waste material is remaining as waste products. Nonetheless, this commodity may find usage in the construction industry that suffers from a shortage of high-quality and easily available aggregates. This work aimed to investigate the optimal substitution of mined natural aggregate with commonly available RAP in order to produce composites with the comparable mechanical performance of reference ordinary Portland concrete. The aggregate substitutions up to 100% with RAP have been studied with a combination of mechanical and analytical techniques. Obtained experimental data showed changes in the porous structure, mineralogy, and in the amount of formed cement-related hydration products that influenced the mechanical performance of produced composites. Composite with 10% of natural aggregate substitution with RAP has shown the strength class C16/20 after 28 days of water curing, according to the EN 206-1. Such innovative products could be utilized in the construction industry. The usage of waste RAP could contribute to preservation of our environment for future generations.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4137
Author(s):  
Quan Liu ◽  
Markus Oeser

The homogeneity of asphalt mixtures blended with reclaimed asphalt pavement (RAP) is affected by many factors. Due to the complicated compositions of recycled asphalt mixtures, the inhomogeneity issue might cause insufficient mechanical properties of asphalt mixtures, even though a design method was appropriately adopted. Therefore, it is of great significance to study the influence of mixing conditions on the homogeneity of asphalt mixtures blended with RAP materials. This study focused on the macro-scale homogeneity of produced asphalt mixtures. Specifically, asphalt mixtures incorporated with 40% RAP content were produced in a laboratory using different mixing times and mixing temperatures. A multi-direction indirect tensile stiffness modulus (ITSM) test was proposed to quantify the homogeneity of produced samples. In addition, the digital image processing (DIP) method was used to identify the distribution of aggregates and RAP binder. The results indicated that the influence of mixing time on the macro-homogeneity of asphalt mixtures indicated that a longer mixing time was favorable for the material dispersion. The influence of mixing temperature mainly rested on two perspectives. One was that the temperature variation induced the change of binder viscosity. The other was that the temperature influences the diffusion process between RAP binder and new bitumen, which further affected the mechanical performance of produced asphalt mixtures.


Author(s):  
Berenice Salaices ◽  
David Teutli ◽  
Imad Abdallah ◽  
Anjan Kumar Siddagangaiah ◽  
Soheil Nazarian

The incorporation of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) in asphalt mixes is encouraged as long as the modified mix exhibits equal or improved performance. Through the integration and data mining from several statewide databases, and extensive laboratory and field testing, this paper investigates the performance of asphalt mixes containing RAP, RAS, or both relative to similar mixes with virgin components. The integration of several databases permitted a network-level investigation of performance patterns. The reasonableness of the observed performance patterns was assessed using the results from the Hamburg wheel tracking tests (HWTT) and indirect tensile strength tests performed on specimens from several sites included in a network-level database. Furthermore, the retrieved network-level data were cross-referenced to the results from a historical performance database. At project level, HWTT and the overlay tester tests were performed on samples from several dozen sites to characterize laboratory performance. Field performance of these sites was also documented through periodic cracking and rutting surveys. From the network-level assessment, the impact of RAP, RAS, or both on the performance of the mixes was found to be mix-dependent. The combination of RAP and RAS seems to negatively affect cracking resistance. Further, dense-graded and Superpave mixes with RAP, RAS, or both exhibit higher cracking potential with minimal impact on rutting resistance. The project-level field performance evaluation shows that fatigue cracking propagates at a higher rate for sections with RAP and RAS than for sections with only RAP.


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


2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Mohammad Ashiqur Rahman ◽  
Rouzbeh Ghabchi ◽  
Musharraf Zaman ◽  
Syed Ashik Ali

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.


2021 ◽  
Vol 304 ◽  
pp. 124653
Author(s):  
Osvaldo Muñoz-Cáceres ◽  
Aitor C. Raposeiras ◽  
Diana Movilla-Quesada ◽  
Daniel Castro-Fresno ◽  
Manuel Lagos-Varas ◽  
...  

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