scholarly journals Evaluation The Moisture Sensitivity of Asphalt Mixtures Modified with Waste Tire Rubber

2022 ◽  
Vol 961 (1) ◽  
pp. 012029
Author(s):  
Hasan H Joni ◽  
Ali H Abed
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Moisture Sensitivity ◽  
Asphalt Mixes ◽  
Modified Asphalt ◽  
The Road ◽  
Road Pavement ◽  
Asphalt Performance ◽  
The Impact

Abstract One of the most significant factors for a good transportation system is the quality of the road pavement. As a result, many steps have been made to address the concerns of moisture damage to roadways, including increasing pavement quality and structural design approaches. In the last few years, there has been an increase in the attention of respective engineers to enhance the asphalt performance and provides various types of modifiers and substituting the virgin of asphaltic materials with recyclable products, to attain sustainable while reducing the price of modified pavement mixture. This article discusses the performance of modified asphalt mixes and the most commonly used recycled product, crumbs rubber, which is used as a modifier in asphaltic mixes at various contents (0, 2.5, 5, 7.5, 10, and 15% by asphalt weight), and investigates the impact of the addition rubber particles on a critical characteristic of asphalt mixtures, particularly regarding their resistance to damage of moisture. The results showed that modification of asphalt binder with CR increased Marshall’s Stability, and the inclusion of 10% of CR recorded the highest increment, increasing by 30.25%. According to increased TSR and IRS, the addition of CR improved the asphalt mixture’s moisture resistance. The addition of 7.5 % of CR resulted in the largest values of TSR and IRS, increasing by 8.8% and 12.9% respectively. Additionally, this study aims at understanding the benefits and drawbacks of recycling rubber tires and to build a concept for effectively incorporating waste materials into road pavement.

Laboratory Assessment of Workability of Asphalt Rubber Hot Mixes Using Warm Mix Technology

2012 ◽  
Vol 193-194 ◽  
pp. 452-457 ◽  
Author(s):  
Meng Yun Huang ◽  
Jing Hui Liu ◽  
Xi Zhang ◽  
Dan Ni Li
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Laboratory Assessment ◽  
Asphalt Mixes ◽  
Modified Asphalt ◽  
The Road ◽  
Asphalt Rubber ◽  
Synergy Effects ◽  
Save Energy

Using the waste crumb rubber modified asphalt to pave the road surface could reduce cost and save energy. However，in order to obtain adequate workability, the mixing temperature and compaction temperature of rubberized asphalt binder and its mixture is much higher than those of conventional asphalt mixtures. Warm Mix Asphalt (WMA) is the name given to certain technologies that reduce the production and placement temperatures of asphalt mixes. One of the main benefits advertised is the increased workability at conventional and lower compaction temperatures with the WMA addition. This paper evaluates whether there are any synergy effects of using warm mix technologies and Asphalt Rubber(AR) hot mixes. This paper summarizes a lab research to evaluate the workability of Asphalt Rubber hot mixes containing warm mix technologies. Both asphalt binder and asphalt mixture were evaluated and compared. The research suggests that combining WMA technology with Asphalt Rubber mixtures is a win-win.

scholarly journals Investigating the Effect of Modifying Aggregate Surface by Micronized Calcium Carbonate on Increasing the Moisture Resistance of Asphalt Mixtures

2018 ◽  
Author(s):  
Mohsen Sohrabi ◽  
Hamid Shirmohammadi ◽  
Gholam Hossein Hamedi
Keyword(s):  
Calcium Carbonate ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Moisture Sensitivity ◽  
Asphalt Mixes ◽  
Mechanical Methods ◽  
Asphalt Mix ◽  
Dry Conditions ◽  
Positive Effect ◽  
Granite Samples

The adhesion between aggregate and asphalt binder in dry conditions, and the amount of its reduction in wet conditions are amongst fundamental indicators that moisture sensitivity amount of asphalt mixtures is dependent to. Among different methods to increase adhesion, modification of aggregates surface with anti-stripping materials is known as an effective method. Therefore, the effect of covering aggregates surface with micronized calcium carbonate as a proper and inexpensive anti-stripping material was investigated. Accordingly, in order to evaluate mixes, first, mechanical methods were used, and then thermodynamic methods were employed to determine the mechanism of the effect of calcium carbonate on increasing asphalt mix resistance to moisture damage. In order to conduct this research, three types of aggregates including limestone, granite, and quartzite, for their different degrees of hydrophilic, and two types of asphalt binder 60–70 and 85–100 were used to produce mixtures. Results obtained by mechanical methods show that modification of aggregates surface causes an increase in the tensile strength ratio (TSR) in the samples made by both two types of asphalt binder. In addition, results of surface free energy method indicate the increase of adhesion energy (except in granite samples) and reduction of debonding energy in all modified samples. Generally, evaluations conducted by the use of both methods show that covering aggregates by micronized calcium carbonate has a positive effect on reducing moisture sensitivity of asphalt mixes.

scholarly journals Modified Asphalt Binder with Natural Zeolite for Warm Mix Asphalt

2015 ◽  
Vol 10 (2) ◽  
pp. 61-68 ◽  
Author(s):  
Marián Dubravský ◽  
Ján Mandula
Keyword(s):  
Natural Zeolite ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Warm Mix Asphalt ◽  
Asphalt Mixtures ◽  
Modified Asphalt ◽  
The Road ◽  
Basic Physic ◽  
Modified Asphalt Binder

Abstract In recent years, warm mix asphalt (WMA) is becoming more and more used in the asphalt industry. WMA provide a whole range of benefits, whether economic, environmental and ecological. Lower energy consumption and less pollution is the most advantages of this asphalt mixture. The paper deals with the addition of natural zeolite into the sub base asphalt layers, which is the essential constituent in the construction of the road. Measurement is focused on basic physic – mechanical properties declared according to the catalog data sheets. The aim of this article is to demonstrate the ability of addition the natural zeolite into the all asphalt layers of asphalt pavement. All asphalt mixtures were compared with reference asphalt mixture, which was prepared in reference temperature.

scholarly journals Evaluation of Rutting and Fatigue Behaviors of Asphalt Binders Modified with Calcium Lignosulfonate

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Saeed Fatemi ◽  
Jafar Bolouri Bazaz ◽  
Seyed Ali Ziaee
Keyword(s):  
Storage Stability ◽  
Asphalt Binder ◽  
Thermal Storage ◽  
Fatigue Performance ◽  
Stability Test ◽  
Asphalt Binders ◽  
Test Results ◽  
Asphalt Mixes ◽  
Modified Asphalt ◽  
The Impact

Asphalt mixes encounter different distress during the life cycle of asphalt pavements, among which rutting and fatigue failure are prominent. Moreover, the addition of environmentally friendly modifiers into the asphalt binder to increase the performance of asphalt mixes has been a challenging phenomenon for researchers. Calcium lignosulfonate (CL) is a waste material that is a by-product of the wood industry. In this paper, the impact of the calcium lignosulfonate on the rutting and fatigue performance of the asphalt binder was investigated. For this purpose, the Dynamic Shear Rheometer (DSR) was utilized to run the Multiple Stress Creep Recovery (MSCR) test and evaluate G ∗ /sinδ and G ∗ ·sinδ indices for the asphalt binder containing different percentages of CL. The elastic recovery test was also conducted on the asphalt binder. In order to analyze the thermal storage stability of CL-modified asphalt binders, the storage stability test was considered. The Field Emission Scanning Electron Microscope test showed that using CL as a binder modifier makes the texture of the asphalt binder spongy and porous. The conventional test results indicated that increasing the CL amount in the asphalt binder led to an increase in the stiffness of the asphalt binder. The rheological test results showed that the rutting resistance of the asphalt binder improved by adding up to 15% of the CL powder; however, the fatigue performance and the elasticity of the asphalt binder declined by increasing the CL content in the asphalt binder. The storage stability test revealed that the dispersion of CL in the asphalt binder was uniform; moreover, the presence of CL in the asphalt binder could not adversely affect the thermal storage stability of the modified asphalt binder.

scholarly journals Material Properties and Environmental Benefits of Hot-Mix Asphalt Mixes Including Local Crumb Rubber Obtained from Scrap Tires

Environments ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 47
Author(s):  
Lim Min Khiong ◽  
Md. Safiuddin ◽  
Mohammad Abdul Mannan ◽  
Resdiansyah
Keyword(s):  
Asphalt Binder ◽  
Crumb Rubber ◽  
Environmental Benefits ◽  
Asphalt Binders ◽  
Rubber Content ◽  
Scrap Tires ◽  
Asphalt Mixes ◽  
Temperature Resistance ◽  
Modified Asphalt ◽  
Marshall Stability

This paper presents the results of a laboratory-based experimental investigation on the properties of asphalt binder and hot-mix asphalt (HMA) mixes modified by locally available crumb rubber, which was used as a partial replacement of asphalt by weight. In this study, fine crumb rubber with a particle size in the range of 0.3–0.6 mm, obtained from scrap tires, was added to the asphalt binder through the wet process. Crumb rubber contents of 5%, 10%, 15%, and 19% by weight of asphalt were added to the virgin binder in order to prepare the modified asphalt binder samples, while the unmodified asphalt binder was used as the control sample. The crumb rubber modified binder samples were examined for measuring viscosity indirectly using the penetration test, and temperature resistance using the softening point test. Later, both the modified and unmodified asphalt binders were used to produce HMA mixes. Two categories of HMA mix commonly used in Malaysia—namely, AC 14 (dense-graded) and SMA 14 (gap-graded)—were produced using the modified asphalt binders containing 5%, 10%, 15%, and 19% crumb rubber. Two AC 14 and SMA 14 control mixes were also produced, incorporating the unmodified asphalt binder (0% crumb rubber). All of the AC 14 and SMA 14 asphalt mixes were examined in order to determine their volumetric properties, such as bulk density, voids in total mix (VTM), voids in mineral aggregate (VMA), and voids filled with asphalt (VFA). In addition, the Marshall stability, Marshall flow, and stiffness of all of the AC 14 and SMA 14 mixes were determined. Test results indicated that the modified asphalt binders possessed higher viscosity and temperature resistance than the unmodified asphalt binder. The viscosity and temperature resistance of the asphalt binders increased with the increase in their crumb rubber content. The increased crumb rubber content also led to improvements in the volumetric properties (bulk density, VTM, VMA, and VFA) of the AC 14 and SMA 14 mixes. In addition, the performance characteristics of the AC 14 and SMA 14 mixes—such as Marshall stability, Marshall flow, and stiffness—increased with the increase in crumb rubber content. However, the AC 14 mixes performed much better than the SMA 14 mixes. The overall research findings suggest that crumb rubber can be used to produce durable and sustainable HMA mixes, with manifold environmental benefits, for use in flexible pavements carrying the heavy traffic load of highways.

scholarly journals Mechanical Characteristics of Graphene Nanoplatelets-Modified Asphalt Mixes: A Comparison with Polymer- and Not-Modified Asphalt Mixes

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2434
Author(s):  
Laura Moretti ◽  
Nico Fabrizi ◽  
Nicola Fiore ◽  
Antonio D’Andrea
Keyword(s):  
Fatigue Resistance ◽  
Graphene Nanoplatelets ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Asphalt Mixes ◽  
Modified Asphalt ◽  
Bituminous Mixtures ◽  
Water Sensitivity ◽  
Polymer Modified Asphalt ◽  
Mechanical Performances

In recent years, nanotechnology has sparked an interest in nanomodification of bituminous materials to increase the viscosity of asphalt binders and improves the rutting and fatigue resistance of asphalt mixtures. This paper presents the experimental results of laboratory tests on bituminous mixtures laid on a 1052 m-long test section built in Rome, Italy. Four asphalt mixtures for wearing and binder layer were considered: two polymer modified asphalt concretes (the former modified with the additive Superplast and the latter modified with styrene–butadiene–styrene), a “hard” graphene nanoplatelets (GNPs) modified asphalt concrete and a not-modified mixture. The indirect tensile strength, water sensitivity, stiffness modulus, and fatigue resistance of the mixtures were tested and compared. A statistical analysis based on the results has shown that the mixtures with GNPs have higher mechanical performances than the others: GNP could significantly improve the tested mechanical performances; further studies will be carried out to investigate its effect on rutting and skid resistance.

scholarly journals Assessments on the Performance of Asphalt Mixtures Prepared with Adhesion Promoters

2019 ◽  
Vol 8 (3S3) ◽  
pp. 332-339
Keyword(s):  
Mechanical Performance ◽  
Water Immersion ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Adhesion Promoters ◽  
Modified Asphalt ◽  
Service Characteristics ◽  
Bonding Properties ◽  
Mechanical Performances

Asphalt pavement is typically susceptible to moisture damage. However, it could be improved with the incorporation of additives or modifiers through binder modifications. The objective of the study is to assess the effect of adhesion promoters, namely PBL and M5000, onto the Hot Mix Asphalt (HMA). The performance of asphalt mixture has been assessed in terms of the service characteristics, the bonding properties, and mechanical performances. The service characteristics were assessed through the Workability Index (WI) and Compaction Energy Index (CEI) to evaluate the ease of asphalt mixture during the mixing and compaction stage. The bonding properties of the modified asphalt mixtures were determined using the boiling water test and static water immersion test to signify the degree of coating after undergoing specific conditioning period and temperature. The mechanical performances of the modified asphalt mixture were evaluated via Marshall stability, semi-circular bending, and modified Lottman tests. All specimens were prepared by incorporating adhesion promoters at the dosage rates of 0.5% and 1.0% by weight of asphalt binder. From the investigation, the bonding properties significantly improved for the modified asphalt mixture compared to the control mixture. The WI of the modified asphalt mixture increased while the CEI decreased in comparison to the control specimen. This implies the workability of modified asphalt mixture is better and requires less energy to be compacted. Modified asphalt mixture generally had better mechanical performance. Therefore, it can be deduced that the asphalt mixture with adhesion promoters have better overall performance than the control mixture.

scholarly journals Qualitative analysis of attitudes to distance learning in the context of the COVID-19 pandemic

2021 ◽  
Vol 27 (1) ◽  
pp. 17-23
Author(s):  
Aleksandr N. Kononov ◽  
Anastasia S. Komissarova
Keyword(s):  
Distance Learning ◽  
Negative Impact ◽  
Educational Institutions ◽  
Full Time ◽  
The Road ◽  
The Russian Federation ◽  
Level Of Motivation ◽  
Study Participants ◽  
The Impact

Topicality of the study of the attitude to the distance learning format is due to the need to study the impact of such interaction in the “pedagogue-studentˮ system on the quality, motivation and overall satisfaction of students with the learning process. The study involved 120 people from 6 six higher education institutions in Moscow. The use of content analysis allowed us to identify 8 significant contexts (areas) around which the statements of the study participants are grouped: “Roadˮ, “Teachersˮ, “Returnˮ, “Distance learningˮ, “Full-time, full-time attendingˮ, “Training, training formatˮ, “Provided, changedˮ, “Qualityˮ. The results obtained indicate that the main disadvantages of the distance learning format, according to the respondents, are the lack of live communication with teachers, a decrease in the level of motivation and self-organisation, which ultimately has a negative impact on the psychoemotional state of students and the quality of material assimilation. At the same time, among the obvious advantages, there is a reduction in transport and time costs for the road to the place of study, as well as the opportunity to study the material at a convenient time. The results obtained can be used in the development of distance learning programmes for students of higher educational institutions of the Russian Federation.

Effect of Coarse Aggregate Morphology on the Resilient Modulus of Hot-Mix Asphalt

2005 ◽  
Vol 1929 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Tongyan Pan ◽  
Erol Tutumluer ◽  
Samuel H. Carpenter
Keyword(s):  
Surface Texture ◽  
Coarse Aggregate ◽  
Resilient Modulus ◽  
Asphalt Binder ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Maximum Aggregate Size ◽  
Asphalt Mixes ◽  
Aggregate Morphology ◽  
The Relationship

The resilient modulus measured in the indirect tensile mode according to ASTM D 4123 reflects effectively the elastic properties of asphalt mixtures under repeated load. The coarse aggregate morphology quantified by angularity and surface texture properties affects resilient modulus of asphalt mixes; however, the relationship is not yet well understood because of the lack of quantitative measurement of coarse aggregate morphology. This paper presents findings of a laboratory study aimed at investigating the effects of the material properties of the major component on the resilient modulus of asphalt mixes, with the coarse aggregate morphology considered as the principal factor. With modulus tests performed at a temperature of 25°C, using coarse aggregates with more irregular morphologies substantially improved the resilient modulus of asphalt mixtures. An imaging-based angularity index was found to be more closely related to the resilient modulus than an imaging-based surface texture index, as indicated by a higher value of the correlation coefficient. The stiffness of the asphalt binder also had a strong influence on modulus. When the resilient modulus data were grouped on the basis of binder stiffnesses, the agreement between the coarse aggregate morphology and the resilient modulus was significantly improved in each group. Although the changes in aggregate gradation did not significantly affect the relationship between the coarse aggregate morphology and the resilient modulus, decreasing the nominal maximum aggregate size from 19 mm to 9.5 mm indicated an increasing positive influence of aggregate morphology on the resilient modulus of asphalt mixes.

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