scholarly journals Environmental Impact Assessment of Different Warm Mix Asphalts

2021 ◽  
Vol 13 (21) ◽  
pp. 11869
Author(s):  
Anda Ligia Belc ◽  
Adrian Ciutina ◽  
Raluca Buzatu ◽  
Florin Belc ◽  
Ciprian Costescu

Within the last decade, much attention has been focused on determining viable techniques for producing sustainable asphalt mixtures and minimizing fuel use and greenhouse gas emissions. Thus, warm mix asphalt (WMA) has become a topic of significant interest among road specialists as it offers a potential solution for reducing the environmental impact of the asphalt mixtures due to the decreased temperatures they require for mixing and compaction compared to hot mix asphalt (HMA). The present study is focused on the Life Cycle Assessment (LCA), according to a “Cradle-to-Gate” approach, of hot mix asphalt and warm mix asphalt prepared with locally available materials and different warm mix additives such as organic additives, chemical additive, and synthetic zeolite. For the analysis of the environmental impact of the warm mix asphalts was used a dedicated software for modeling and evaluating the LCA. The WMA prepared with chemical additive or organic additive led to a decrease of the environmental impact, in the production phase, compared to HMA. The study reveals that the raw materials extraction has the greatest impact on the environment in all studied cases, followed by the actual production phase of the asphalt mixture. For WMA produced with additives there was a decrease in the global impact on the environment compared to HMA.

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3534
Author(s):  
Anda Ligia Belc ◽  
Erdem Coleri ◽  
Florin Belc ◽  
Ciprian Costescu

The interest in minimising fuel consumption and greenhouse gas emissions among road specialists is increasing. Thus, methods for reducing asphalt concrete mixing and compaction temperatures by a few tens of degrees Celsius without compromising the long-term performance has become a topic of significant interest. This study is focused on the analysis of warm mix asphalt (WMA) prepared with locally available materials in order to determine the suitable technology applicable to the specific traffic and climatic conditions of Romania. WMA was prepared using different warm mix additives (organic additives, chemical additive, and synthetic zeolite) at different mixing and compaction temperatures, and bitumen blends with these additives were analysed by carrying out the dynamic shear rheometer test and evaluating the penetration index. In conclusion it was noted that most additives did not lead to a significant change of bitumen`s characteristics, but the organic additive had a big influence on the bitumen`s properties. The characteristics of WMA are very similar to those of HMA. The mixing and compaction temperatures could be reduced by approximately 40 °C when WMA was blended with the additives without compromising the performance of the asphalt mixture, compared to hot mix asphalt.


2013 ◽  
Vol 723 ◽  
pp. 551-556
Author(s):  
Ling Meng

Nowadays, engineers begin to pay more attention on field-aged asphalt concrete cores because they have more reality than the lab-made cores and the results can tell what happened to the pavement. However, it is not accurate to estimate the full asphalt mixture because as usual the pavement engineers can only extract the binder from it, not the mixture. Now there is a newly developed way to analysis the data more accurately using the Direct Tension Test. Because the field aged asphalt mixtures are not aged uniformly with the pavement depth because of various reasons, there is a modulus gradient going through deeply through the asphalt layer and usually the stiffest layer is the surface because normally the surface is more aged. A method has been developed to analysis this behavior. Tests are both taken on field cores which are Hot Mix Asphalt (HMA) and Warm Mix Asphalt (WMA). During the research, the authors found that it is both applicable for all the field cores. More information about this method and tests are detailed in the following paragraphs.


2016 ◽  
Vol 5 (2) ◽  
pp. 50-60
Author(s):  
Claudia Petcu ◽  
Carmen Răcănel

Abstract “Warm Mix Asphalt” (WMA) is a technology developed to obtain an asphalt mixture at lower temperatures. The method has significant benefits for the economic and environmental area. As known, “warm mix asphalt” uses additives in bitumen having the purpose to reduce the viscosity in order to decrease the mixing and compaction temperatures. Hot mix asphalt used in the airport area, especially the area of taxiway and the apron must satisfy beside usual requirements for roads, some requirements related to fuel resistance and de-icing agents according to European norms. Does warm mix asphalt for airport use meet the requirements according to European norms? This is the question from this paper which aims to determine the characteristics of asphalt mixtures for airports BBA16 when using or not using an additive, considering a series of laboratory tests: cyclic triaxial compression test, fatigue test, stiffness modulus test and resistances to fuels test.


2014 ◽  
Vol 3 (1) ◽  
pp. 35-42
Author(s):  
Carmen Răcănel ◽  
Adrian Burlacu

Abstract The benefits of WMA technologies include reduced fuel usage and emissions in support of sustainable development, improved field compaction, which can facilitate longer haul distances and cool weather pavement, and better working conditions. Since this is a relatively new technology, it is necessary to determine the behavior and the performances of this type of asphalt mixture depending on additive percent. These technologies tend to reduce the viscosity of the asphalt and provide for the complete coating of aggregates at lower temperatures. WMA is produced at temperatures 20 to 30°C lower than typical hot-mix asphalt (HMA). The paper presents the results obtained in the Road Laboratory of Technical University of Civil Engineering Bucharest on an asphalt mixture with fibers (MASF16) prepared according to the “warm mix” technology with chemical additive. Different percent of additive are used in laboratory to draw up the “master curves” of asphalt mixture obtained by 4PB-PR stiffness modulus results.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Yongjoo Kim ◽  
Jaejun Lee ◽  
Cheolmin Baek ◽  
Sunglin Yang ◽  
Sooahn Kwon ◽  
...  

A number of warm-mix asphalt (WMA) technologies are used to reduce the temperature at which the asphalt mixtures are produced and compacted, apparently without compromising the performance of the pavement. The main objective of this study is to determine whether the use of an innovative wax-based LEADCAP WMA additive influences the performance of the asphalt mixture, which is produced and compacted at significantly low temperatures. The WMA pavement using LEADCAP additive (WMA-LEADCAP) along with a control HMA pavement was evaluated with respect to their performances of rutting resistance, crack resistance, and viscoelastic property based on the laboratory dynamic modulus test, indirect tensile strength test, and in-door accelerated pavement test (APT) results. With the limited data carried out, the LEADCAP additive is effective in producing and paving asphalt mixture at approximately 30°C lower temperature than a control HMA mixture, and the performances of WMA-LEADCAP pavement are comparable to a control HMA pavement.


2017 ◽  
Vol 67 (327) ◽  
pp. 123 ◽  
Author(s):  
A. M. Rodríguez-Alloza ◽  
J. Gallego

Warm Mix Asphalt (WMA) refers to technologies that reduce manufacturing and compaction temperatures of asphalt mixtures allowing lower energy consumption and reducing greenhouse gas emissions from asphalt plants. These benefits, combined with the effective reuse of a solid waste product, make asphalt rubber (AR) mixtures with WMA additives an excellent environmentally-friendly material for road construction. The effect of WMA additives on rubberized mixtures has not yet been established in detail and the lower mixing/compaction temperatures of these mixtures may result in insufficient compaction. In this sense, the present study uses a series of laboratory tests to evaluate the volumetric characteristics and compactability of AR mixtures with organic additives when production/compaction temperatures are decreased. The results of this study indicate that the additives selected can decrease the mixing/compaction temperatures without compromising the volumetric characteristics and compactability.


2018 ◽  
Vol 7 (4.20) ◽  
pp. 338
Author(s):  
Gholamali Shafabakhsh ◽  
Hassan Divandari ◽  
Seyed Reza Sajadi

Durability of asphalt pavements is related to choosing proper materials. Fillers as the smallest particles of stone materials, and one of the most important parts of asphalt mixtures, exert pivotal effects on the performance of asphalt mixtures, by filling empty spaces and because of their softness, surface features and chemical compounds. Rice husk ash is one of the waste products of burning rice husk in powerhouses that is accounted as biomass. Recently, a good many of investigations have shown that rice husk ash, as a high quality pozzolan, can be properly replaced of common aggregates. In this study rice husk ash was used as filler in hot mix asphalt, and the result mixtures’ mechanical properties was compared with ordinary mixtures whose filler was stone powder. Asphalt mixture samples with two different aggregate graded, and 0, 25, 50, 75 and 100 percent of rice husk ash which were the substitution of stone powder content, were made and the effects of using rice husk ash on the moisture sensitivity, resilience modulus, rutting and dynamic creep of asphalt mixtures were investigated. The results demonstrated that increase of using rice husk ash as the replacement of prevalent fillers in hot mix asphalts, noticeably improves their performance; however, because of excessive stiffness created by rice husk ash, it's better to use it in optimized percentage. Accordingly, statistical analysis of the tests’ results leads to presenting an optimized model for the content of Rice Husk Ash to be used in hot mix asphalt. Finally, Rice Husk Ash content were suggested 26% for graded number 4 and 48% for graded number 5 as replacements for stone powder filler. 


2013 ◽  
Vol 446-447 ◽  
pp. 1429-1435
Author(s):  
Jin Xi Zhang ◽  
Kai Mu ◽  
Wen Tao Wang

A kind of new warm mix additive called SAP was proposed in this paper. The principle is using foam to lower the operating temperature of asphalt mixtures. The mixing and molding temperature of SAP warm mix asphalt mixture were measured by viscosity method and void ratio method, which are almost 20°C lower than that of HMA. Considering the engineering applications and test accuracy, the void ratio method is considered to be the better way to measure the operating temperature of asphalt mixtures.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3200
Author(s):  
Francesca Russo ◽  
Rosa Veropalumbo ◽  
Salvatore Antonio Biancardo ◽  
Cristina Oreto ◽  
Fabio Scherillo ◽  
...  

Secondary raw materials consist of production waste or material resulting from recycling processes, currently in large quantities, which can be injected back into the economic system as new raw materials. This study proposes jet grouting waste (JGW) as filler for hot and cold asphalt mixtures applied as base layers of road pavements and investigates the physical and mechanical properties. JGW is derived from soil consolidation performed during underground roadway tunnel construction. The research compares three asphalt mixtures: (a) hot mixture containing limestone aggregate-filler (HMA), (b) HMA containing JGW (HMAJ), (c) cold recycled asphalt mixture containing JGW (CRAJ). Leaching tests of JGW and reclaimed asphalt pavement (RAP) were conducted; the best configurations of the three mixtures were determined by using the volumetric method through gyratory compaction. Three mastics with filler-to-binder ratios reflecting those of the asphalt mixtures were investigated through delta ring and ball test and frequency sweep test at 0.05% stress by using a dynamic shear rheometer. The morphology of each mixture was further investigated by scanning electron microscopy. The results showed that CRAJ with 28 days of curing time reached the indirect tensile strength (ITS) of HMA (0.73 MPa) within 14 days and, among all studied mixtures, returned the lowest cumulative strain, which was on average 30% lower than that of HMA and HMAJ. The results of this study have shown that the cold alternative mixture, CRAJ, promotes the reuse of two types of waste, RAP and JGW, as it fully meets the reference Italian Technical Standard and ensures good mixture performance in addition to conserving natural resources.


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