Additive Percent Influence on “Warm Mix” Behavior

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.

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Hot-mix asphalt compaction evaluation with field tests

The Baltic Journal of Road and Bridge Engineering ◽

10.3846/bjrbe.2014.37 ◽

2014 ◽

Vol 9 (4) ◽

pp. 306-316 ◽

Cited By ~ 3

Author(s):

Rui Micaelo ◽

Maria C. Azevedo ◽

Jaime Ribeiro

Keyword(s):

Field Test ◽

Regression Models ◽

Hot Mix Asphalt ◽

Asphalt Mixture ◽

Field Tests ◽

Dynamic Compaction ◽

Large Field ◽

Field Compaction ◽

Compaction Degree

The objective of this study is to determine the influence of field compaction conditions on hot-mix asphalt layers compaction. A large field test was carried out to assess the compaction degree variation under field conditions such as the type of layer, the temperature and the roller (weight and compaction mode). Compaction evolution with roller passes of two asphalt layers was assessed in-situ with a nuclear and a non-nuclear measurement device. The analysis of the compaction results with regression models showed that the temperature, the roller weight and the asphalt mixture are the most influential and that the frequency, for all dynamic compaction modes, is not relevant. Finishing compaction increases layer’s compaction degree up to 2%. The two different density gauges used in this study measured different compaction degree values.

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Environmental Impact Assessment of Different Warm Mix Asphalts

Sustainability ◽

10.3390/su132111869 ◽

2021 ◽

Vol 13 (21) ◽

pp. 11869

Author(s):

Anda Ligia Belc ◽

Adrian Ciutina ◽

Raluca Buzatu ◽

Florin Belc ◽

Ciprian Costescu

Keyword(s):

Environmental Impact ◽

Hot Mix Asphalt ◽

Raw Materials ◽

Asphalt Mixture ◽

Warm Mix Asphalt ◽

Organic Additive ◽

Asphalt Mixtures ◽

Organic Additives ◽

Chemical Additive ◽

Production Phase

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.

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The Influence of Eggshell as Coarse Aggregate Replacement in Hot Mix Asphalt

CONSTRUCTION ◽

10.15282/construction.v1i1.6180 ◽

2021 ◽

Vol 1 (1) ◽

pp. 1-11

Author(s):

Ng Cui Ming ◽

Ramadhansyah Putra Jaya ◽

Haryati Awang

Keyword(s):

Hot Mix Asphalt ◽

Coarse Aggregate ◽

Asphalt Mixture ◽

Aggregate Size ◽

Modified Asphalt ◽

The Road ◽

Road Pavement ◽

Road Users ◽

Indirect Tensile ◽

Pavement Structures

Hot Mix Asphalt (HMA) is the most commonly used in Malaysia for highways, interstates and roads due to its flexibility, economical, strong and provide safe riding quality for road users. Over the years, the increase of damage on pavement roads in Malaysia has become a severe issue although the road did not achieve its design life. Hence, to reduce damage and defect, an improvised road pavement structures is needed. Various studies have been conducted to identify the new materials that can be used as a replacement in hot mix asphalt. In this research, the purpose is to evaluate the performance of eggshell as coarse aggregate replacement in hot mix asphalt. The gradation for aggregate used in this mixture is AC14. The weight for total mixing of the aggregates used is 1200g while the grade for bitumen is 60/70. The samples were mixed with eggshell in the various percentages of 0%, 5%, 10%, 15% and 20% by total weight of aggregate size 5mm. The laboratory tests carried out to determine the properties of aggregates included, aggregate impact value and aggregate crushing value. Besides, penetration and softening point were also performed to determine the properties of bitumen. Several types of test were conducted towards the samples, which are Marshall Test, Indirect Tensile Strength and Cantabro Test. The results exhibit that the conventional asphalt mixture is more effective than modified asphalt mixture. The replacement of eggshell as coarse aggregate was not enough improvement to the performance of asphalt pavement as the performance of conventional mixture is more stable than modified mixture.

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Study on Pavement Performance of Warm Mix Asphalt with DAT

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.709.354 ◽

2014 ◽

Vol 709 ◽

pp. 354-357

Author(s):

Kun Wang ◽

Xiang Qu

Keyword(s):

Hot Mix Asphalt ◽

Asphalt Mixture ◽

Temperature Stability ◽

Warm Mix Asphalt ◽

Pavement Performance ◽

High Temperature Stability ◽

Molding Temperature ◽

The Road ◽

The Difference ◽

The Impact

To study the difference of pavement performance between DAT warm-mix asphalt and hot-mix asphalt, the impact on the SBS asphalt with 10% DAT was studied first. Then AC-5 asphalt mixture was made the Marshall specimens according to the indoor mixing and molding temperature. Analyze the road performance between warm mix asphalt and hot mix asphalt. The experiment results show that the SBS asphalt with DAT has small difference to the original. The DAT warm-mix asphalt has poor water stability and low-temperature stability but good high-temperature stability than the hot mix asphalt when the indoor mixing and molding temperature has 20°C reduction. So DAT warm-mix asphalt can achieve the purpose of energy saving.

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“Warm Mix Asphalt’’ for Airport Use

Romanian Journal of Transport Infrastructure ◽

10.1515/rjti-2016-0048 ◽

2016 ◽

Vol 5 (2) ◽

pp. 50-60

Author(s):

Claudia Petcu ◽

Carmen Răcănel

Keyword(s):

Fatigue Test ◽

Compression Test ◽

Laboratory Tests ◽

Hot Mix Asphalt ◽

Triaxial Compression ◽

Asphalt Mixture ◽

Warm Mix Asphalt ◽

Asphalt Mixtures ◽

Stiffness Modulus ◽

Fuel Resistance

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.

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Experimental Study on Mix Ratio Design and Road Performance of Medium and Small Deformation Seamless Expansion Joints of Bridges

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198120984741 ◽

2021 ◽

pp. 036119812098474

Author(s):

Pengzhen Lu ◽

Chenhao Zhou ◽

Simin Huang ◽

Yang Shen ◽

Yilong Pan

Keyword(s):

Traffic Safety ◽

Performance Test ◽

Asphalt Mixture ◽

Small Deformation ◽

Expansion Joint ◽

Expansion Joints ◽

Mixture Ratio ◽

The Road ◽

Marshall Test ◽

Road Performance

Expansion joints are a weak and fragile part of bridge superstructure. The damage or failure of the expansion joint will lead to the decline of bridge durability and endanger the bridge structure and traffic safety. To improve the service life and performance of bridge expansion joints, the ideal method is to use seamless expansion joints. In this study, starting from the commonly used asphalt mixture gradation of seamless expansion joint, and taking into account the actual situation of bridge expansion joint structure and environment in China, the gradation and asphalt-aggregate ratio are preliminarily designed. Through a Marshall test, the corresponding asphalt mixture is evaluated and analyzed according to the stability, flow value, and void ratio, and the optimal gradation and asphalt-aggregate ratio are determined. Finally, the asphalt mixture is prepared with the mixture ratio design, and the test results of an immersion Marshall test, fatigue performance test, and full-scale test verify that the asphalt mixture meets the road performance requirements of seamless expansion joints. On the basis of the experimental data, the performance of large sample asphalt mixture is continuously tested, compared, and optimized. The results show that the asphalt mixture ratio designed is true and reliable, which can provide reference for the optimal design of seamless expansion joint filler.

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Investigation of the Formation Mechanism and Environmental Risk of Tire—Pavement Wearing Waste (TPWW)

Sustainability ◽

10.3390/su13158172 ◽

2021 ◽

Vol 13 (15) ◽

pp. 8172

Author(s):

Kechen Wang ◽

Xiangyu Chu ◽

Jiao Lin ◽

Qilin Yang ◽

Zepeng Fan ◽

...

Keyword(s):

Formation Mechanism ◽

Organic Contaminants ◽

Asphalt Mixture ◽

Fine Fraction ◽

Crumb Rubber ◽

Environmental Benefit ◽

The Road ◽

Open Graded Friction Course ◽

Volatile Alkanes ◽

Physical And Chemical

Tire—pavement interaction behaviours result in large amounts of wearing waste matter, which attaches to the surface of the pavement and is directly exposed to the surrounding environment. This kind of matter imposes a great challenge to the environment of the road area. The current study is devoted to carrying out a comprehensive investigation of the formation mechanism of tire—pavement wearing waste (TPWW), as well as the resulting environmental risks. A self-developed piece of accelerated polishing equipment, the Harbin advanced polishing machine (HAPM), was employed to simulate the wearing process between vehicle tires and pavement surfaces, and the TPWW was collected to conduct morphological, physical, and chemical characterisations. The results from this study show that the production rate of TPWW decreases with the increase in polishing duration, and the coarse particles (diameters greater than 0.425 mm) account for most of the TPWW obtained. The fine fraction (diameter smaller than 0.425 mm) of the TPWW comprises variously sized and irregularly shaped rubber particles from the tire, as well as uniformly sized and angular fine aggregates. The environmental analysis results show that volatile alkanes (C9–C16) are the major organic contaminants in TPWW. The Open-Graded Friction Course (OGFC) asphalt mixture containing crumb rubber as a modifier showed the highest risk of heavy metal pollution, and special concern must be given to tire materials for the purpose of improving the environmental conditions of road areas. The use of polyurethane as a binder material in the production of pavement mixtures has an environmental benefit in terms of pollution from both organic contaminants and heavy metals.

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Laboratory Investigation of Compaction Characteristics of Plant Recycled Hot-Mix Asphalt Mixture

Sustainability ◽

10.3390/su13063005 ◽

2021 ◽

Vol 13 (6) ◽

pp. 3005

Author(s):

Jiangang Yang ◽

Chen Sun ◽

Wenjie Tao ◽

Jie Gao ◽

Bocheng Huang ◽

...

Keyword(s):

Regression Model ◽

Hot Mix Asphalt ◽

Orthogonal Experiment ◽

Asphalt Mixture ◽

Material Design ◽

Void Content ◽

Range Analysis ◽

Aggregate Gradation ◽

Compaction Characteristics ◽

Compaction Energy

In this study, the compaction characteristics of recycled hot-mix asphalt (RHMA) were evaluated using the void content (VV), compaction energy index (CEI), slope of accumulated compaction energy (K), and lock point (LP). Then, the effects of the compaction parameters, including the gradation of the RHMA, reclaimed asphalt pavement (RAP) content, temperature of gyrations, and number of gyrations, on the compaction characteristics of RHMA were investigated. An orthogonal experiment was designed and the data collected were analyzed via range analysis; then, a regression model was generated relying on a quadratic polynomial. Furthermore, the regression model was used for the comparison and prediction of the mixture’s compactability during the material design. Finally, the compaction mechanism of RHMA was discussed from the perspective of the void content of RAP particles. The results showed that a finer aggregate gradation, a higher gyration temperature, a greater number of gyrations, and a higher RAP content were effective for increasing the compactability of RHMA. The range analysis results suggest that the gradation of RHMA has the greatest influence on compactability, followed by the RAP content. The RAP aggregate cannot diffuse to a new mixture completely, so the remained RAP particle reduces the void content of RHMA. Therefore, a higher RAP content up to 50% can help RHMA to achieve the designed void content with higher efficiency.

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Harnessing COVID-Driven Technical Innovations for Improved Multi-Disciplinary Cancer Care in the Post-COVID Era: The Virtual Patient Room

Cancer Control ◽

10.1177/1073274820964800 ◽

2020 ◽

Vol 27 (1) ◽

pp. 107327482096480 ◽

Cited By ~ 1

Author(s):

Austin J. Sim ◽

Gage Redler ◽

Jeffrey Peacock ◽

Cristina Naso ◽

Stuart Wasserman ◽

...

Keyword(s):

New Technology ◽

Multidisciplinary Care ◽

Virtual Patient ◽

Paradigm Shifts ◽

Patient Room ◽

Patient Centered ◽

Team Members ◽

The Road ◽

Centered Care ◽

Virtual Visits

Emergence of the COVID-19 crisis has catalyzed rapid paradigm shifts throughout medicine. Even after the initial wave of the virus subsides, a wholesale return to the prior status quo is not prudent. As a specialty that values the proper application of new technology, radiation oncology should strive to be at the forefront of harnessing telehealth as an important tool to further optimize patient care. We remain cognizant that telehealth cannot and should not be a comprehensive replacement for in-person patient visits because it is not a one for one replacement, dependent on the intention of the visit and patient preference. However, we envision the opportunity for the virtual patient “room” where multidisciplinary care may take place from every specialty. How we adapt is not an inevitability, but instead, an opportunity to shape the ideal image of our new normal through the choices that we make. We have made great strides toward genuine multidisciplinary patient-centered care, but the continued use of telehealth and virtual visits can bring us closer to optimally arranging the spokes of the provider team members around the central hub of the patient as we progress down the road through treatment.

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Research on New Technology to Control Highway Semi-Rigid Base Asphalt Pavement Cracks

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.1632 ◽

2011 ◽

Vol 194-196 ◽

pp. 1632-1638

Author(s):

Hong Liang Deng ◽

Xiao Yin Fu ◽

Wen Xue Gao ◽

Ting Ting Ni ◽

Kai Jiang Chen

Keyword(s):

Composite Materials ◽

Theoretical Calculations ◽

Asphalt Pavement ◽

New Technology ◽

Service Level ◽

Self Control ◽

Good Effect ◽

Rigid Base ◽

The Road ◽

Absorbing Layer

The methods of controlling Highway semi-rigid base asphalt pavement cracks and other diseases are always hot fields of road engineering and academic circles. The existing methods are on some degree efficient on delaying the formation and extension of cracks, but the effect is limited with different methods and various mechanisms of preventing cracks. Base on force analysis of pavement, this article presents a new technology of crack controlling which uses intelligent composite materials interlayer. By adding a stress absorbing layer between the asphalt surface layers or the semi-rigid base layers with low modulus, good toughness, self-adaptability and self-control ability, the intelligent composite materials interlayer has a good effect on controlling cracks which has been proved by the theoretical calculations and experimental analysis. As a result, the intelligent composite materials interlayer could efficiently prevent and delay the formation and extension of cracks, the safety and comfort of highway could be improved significantly while the cost of construction and maintenance decreasing. And the service level and social image of the road could also be improved effectively. This research has important academic and application value.

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