Effects of asphalt modification by Nanosilica and Nanoclay on asphalt binder and hot mix asphalt properties

From the environmental conservation perspective, warm mix asphalt is more preferable compared to hot mix asphalt. This is because warm mix asphalt can be produced and paved in the temperature range 20–40°C lower than its equivalent hot mix asphalt. In terms of cost-effectiveness, warm mix asphalt can significantly improve the mixture workability at a lower temperature and thus reduce greenhouse gas emissions, to be environment friendly. However, the concern, which is challenging to warm mix asphalt, is its susceptibility to moisture damage due to its reduced production temperature. This may cause adhesive failure, which could eventually result in stripping of the asphalt binder from the aggregates. This research highlights the significance of Cecabase warm mix additive to lower the production temperature of warm mix asphalt and improvise the asphalt binder adhesion properties with aggregate. The binders used in the preparation of the test specimen were PG-64 and PG-76. The contact angle values were measured by using the dynamic Wilhelmy plate device. The surface free energy of Cecabase-modified binders was then computed by developing a dedicated algorithm using the C++ program. The analytical measurements such as the spreadability coefficient, work of adhesion, and compatibility ratio were used to analyze the results. The results inferred that the Cecabase improved the spreadability of the asphalt binder over limestone compared to the granite aggregate substrate. Nevertheless, the Cecabase-modified binders improved the work of adhesion. In terms of moisture sensitivity, it is also evident from the compatibility ratio indicator that, unlike granite aggregates, the limestone aggregates were less susceptible to moisture damage.

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Experimental Study to Determine the Most Preferred Additive for Improving Asphalt Performance Using Polypropylene, Crumb Rubber, and Tafpack Super in Medium and High-Temperature Range

Applied Sciences ◽

10.3390/app9081567 ◽

2019 ◽

Vol 9 (8) ◽

pp. 1567 ◽

Cited By ~ 5

Author(s):

Huang Xiaoming ◽

Ismail Bakheit Eldouma

Keyword(s):

High Temperature ◽

Physical Properties ◽

Mechanical Performance ◽

Asphalt Binder ◽

Crumb Rubber ◽

Asphalt Binders ◽

Modified Bitumen ◽

Asphalt Modification ◽

Rotational Viscosity ◽

Asphalt Performance

The overall objectives of this study were to determine the most appropriate additive for improving the physical properties and the medium- and high-temperature performances (mechanical performance) of asphalt binders. Three different types of modified binders were prepared: crumb rubber modifier (CRM), polypropylene (PP), and tafpack super (TPS), which had concentrations of 2%, 3%, 3.5%, and 4% by weight of asphalt binder, for each modifier. Their physical and rheological properties were evaluated by applying various tests such as ductility, rotational viscosity, toughness, and tenacity, as well as the dynamic shear rheometer (DSR) test. As a result, the physical properties of the modified bitumen binders were compared, as were the medium- and high-temperature performances (mechanical performance), which had temperatures of 58, 64, 70, 76, 82, and 88 °C, respectively. This was how the most appropriate modifier was determined. The results demonstrated that the asphalt binder properties significantly improved by utilizing CRM followed by PP and TPS modifiers. The increase in the rutting parameter (G*/sin(δ)) after asphalt modification indicated its excellent performance at both medium- and high-temperatures. Lastly, the CRM was determined as the most preferred additive because of its positive effect on the physical properties and enhancement of the medium- and high-temperature performance (mechanical performance).

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Performance Evaluation of Hot-Mix Asphalt Using Rotary Loaded-Wheel Testing

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198105192900119 ◽

2005 ◽

Vol 1929 (1) ◽

pp. 157-164

Author(s):

M. Shane Buchanan ◽

Benjamin J. Smith

Keyword(s):

Hot Mix Asphalt ◽

Permanent Deformation ◽

Asphalt Binder ◽

Hydrated Lime ◽

New Device ◽

Proof Testing ◽

Reasonable Prediction ◽

The Cost ◽

Performance Results ◽

Transportation Agencies

Permanent deformation and moisture damage (i.e., rutting and stripping) are two predominant hot-mix asphalt (HMA) distresses. Rutting can be caused by many factors, including stripping, which result in reduced HMA shear strength. Hot-mix asphalt stripping evaluation is a source of significant industry discussion and debate. Transportation agencies use a number of methods to evaluate stripping, with many methods customized depending on local concerns and environmental conditions. Today, many agencies use some type of loaded-wheel testing, with associated mix “pass–fail” criteria, as part of the mix design acceptance procedure. This process is often referred to as “proof” testing and provides a higher confidence that the HMA mix will perform satisfactorily during service conditions. A new device, the rotary wheel tester, has been developed to evaluate the rutting and stripping performance of HMA mixes. This device operates on a principle similar to that of the Hamburg wheel tester: the main difference is that the specimen is loaded along its diameter instead of from the top. The cost of the rotary wheel tester is less than half that of the Hamburg wheel tester. Testing was conducted to determine whether the rotary wheel tester could distinguish between good- and poor-performing mixes and to determine whether PG 76-22 or PG 67-22 plus hydrated lime improved mix performance. Results indicate that the rotary wheel tester is an easy-to-use testing device that appears to provide reasonable prediction of the rutting and stripping performance of HMA mixes. It also appears that PG 76-22 asphalt binder improves mix performance to a greater extent than does PG 67-22 plus hydrated lime.

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Using ceramic wastes from tile industry as a partial substitute of natural aggregates in hot mix asphalt binder courses

Construction and Building Materials ◽

10.1016/j.conbuildmat.2013.03.058 ◽

2013 ◽

Vol 45 ◽

pp. 115-122 ◽

Cited By ~ 25

Author(s):

Ramón Silvestre ◽

Esther Medel ◽

Alfredo García ◽

José Navas

Keyword(s):

Hot Mix Asphalt ◽

Asphalt Binder ◽

Natural Aggregates

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Highly Modified Asphalt Binder for Asphalt Crack Relief Mix

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/2630-14 ◽

2017 ◽

Vol 2630 (1) ◽

pp. 110-117 ◽

Cited By ~ 3

Author(s):

Matheus S. Gaspar ◽

Kamilla L. Vasconcelos ◽

Amanda H. M. da Silva ◽

Liedi L. B. Bernucci

Keyword(s):

Hot Mix Asphalt ◽

Asphalt Binder ◽

Asphalt Mixture ◽

Bending Test ◽

Asphalt Binders ◽

Reflective Cracking ◽

Modified Asphalt ◽

Asphalt Overlay ◽

Modified Asphalt Binder ◽

Styrene Butadiene

Reflective cracking is a common issue with respect to rehabilitated asphalt pavements, especially when the rehabilitation is done by applying a hot-mix asphalt overlay on the existing damaged pavement. Several approaches can be adopted to delay reflective cracking. They include an increase of the overlay thickness and the use of a stress relief asphalt mixture (SRAM), which is a fine-graded, flexible, and thin asphalt interlayer. Because the efficiency of a SRAM is highly related to the properties of the asphalt binder used in the mixture, it is of interest to use a highly modified asphalt (HiMA) binder. This paper describes a field test comprising three sections at BR-116 (a heavily trafficked highway in Brazil). One of the rehabilitation strategies used for a cracked asphalt pavement was a 2.5-cm SRAM (produced with a HiMA binder) and 5-cm styrene–butadiene–styrene (SBS) hot-mix asphalt (HMA). The other two strategies were to apply SBS HMA overlays of different thicknesses (7.5 cm and 10.5 cm). The aim was to evaluate and compare the capability of these solutions to control reflective cracking. Rheological properties and multiple stress creep and recovery tests were performed on the asphalt binders, and the semicircular bending test was performed on the asphalt mixtures. The surface conditions were monitored, and the results for each section were compared. After a 29-month period, the section that received the interlayer had the lowest cracked area and showed better resistance than the overlays did to reflective cracking and better maintenance of the original thickness of the pavement.

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Use of Screenings to Produce Hot-Mix Asphalt Mixtures

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1832-08 ◽

2003 ◽

Vol 1832 (1) ◽

pp. 59-66 ◽

Cited By ~ 1

Author(s):

L. Allen Cooley ◽

Jingna Zhang ◽

Michael H. Huner ◽

E. Ray Brown

Keyword(s):

Hot Mix Asphalt ◽

Asphalt Binder ◽

Cellulose Fiber ◽

Fine Aggregate ◽

Structural Improvement ◽

Maintenance And Rehabilitation ◽

Modified Asphalt Binder ◽

Maximum Particle ◽

Air Void ◽

Different Sources

Thin-lift hot-mix asphalt (HMA) layers are utilized in almost every maintenance and rehabilitation application. These mix types require smaller maximum particle sizes than do most conventional HMA surface layers. Although the primary functions of thin-lift HMA are to level the pavement surface, smooth the surface, or slow the deterioration of the existing pavement, or all three, these mixes may also provide some structural improvement, depending on the layer thickness placed. The use of manufactured aggregate screenings (fine aggregate stockpiles) as the sole aggregate portion of an HMA mixture was evaluated in this study. Mixes of this nature have the potential for use as thin-lift HMA layers. Two different sources of aggregate screenings, granite and limestone, were utilized to design mixtures at varying design air void contents and then tested for rut susceptibility. The use of a neat versus a modified asphalt binder was also evaluated, as well as the potential advantages of cellulose fiber additives. These mixtures using 100% manufactured screenings proved to be acceptable with regard to rutting resistance. No work was performed in this study to examine thermal cracking or durability.

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Application of biochar from crop straw in asphalt modification

PLoS ONE ◽

10.1371/journal.pone.0247390 ◽

2021 ◽

Vol 16 (2) ◽

pp. e0247390

Author(s):

Xinli Gan ◽

Wenli Zhang

Keyword(s):

Electron Microscopy ◽

Particle Size ◽

High Temperature ◽

High Speed ◽

Asphalt Binder ◽

Crop Straw ◽

Modified Asphalt ◽

Temperature Performance ◽

Asphalt Modification ◽

Scanning Electron

The objective of this study is to verify the feasibility of using biochar made from crop straw as a bitumen additive to improve some properties of bitumen. The differences between crop straw biochar prepared in a laboratory and commercial charcoal were investigated through scanning electron microscopy and laser particle size analyses. Furthermore, biochar-modified asphalt was prepared using the high-speed shear method, and the penetration, softening point, ductility at 15°C, and apparent viscosity of the asphalt binder with 6% biochar were measured at 120, 135, 150, 160, and 175°C. It was found that both the crop straw biochar and the commercial charcoal consist mainly of C, O, Si, and K, but the C content of crop straw biochar is slightly higher than that of commercial charcoal. The particle size of biochar is smaller than that of commercial charcoal, while the specific surface area is larger. It was determined that the addition of crop straw biochar significantly improved the high-temperature performance of asphalt, and that biochar and commercial charcoal have a similar influence on the high temperature performance of asphalt.

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Evaluation of Carbon Nanotubes Asphalt Modification Using the Superpave Criteria

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.902.135 ◽

2021 ◽

Vol 902 ◽

pp. 135-143

Author(s):

Mohammad Ali Khasawneh ◽

Khalid Ghuzlan ◽

Nada Bani Melhem

Keyword(s):

Carbon Nanotubes ◽

Low Temperature ◽

Rheological Properties ◽

Asphalt Binder ◽

Fatigue Cracking ◽

Asphalt Binders ◽

Asphalt Pavements ◽

Low Temperature Cracking ◽

Asphalt Modification ◽

Rotational Viscosity

Rutting, fatigue cracking and low temperature cracking are the most important distresses in asphalt pavements as a result of changes in rheological properties of asphalt binder. Many types of modifiers were used to enhance asphalt behavior at both low and high temperatures. In this study, carbon nanotubes (CNT) were used as one of many nanomaterials that take a large attention in the latest research related to asphalt modification against different types of distresses. Effect of CNT on rheological properties of asphalt binder was investigated by testing unmodified and CNT modified asphalt binders using two of Superpave devices: Dynamic Shear Rheometer (DSR) and Bending Beam Rheometer (BBR). Penetration, softening point, flash point and rotational viscosity (RV) tests were carried out as well. CNT was added in 0.1%, 0.5% and 1% by weight of asphalt binder. It was found that adding CNT in 0.5% and 1% increase stiffness of asphalt and consequently asphalt pavement rutting resistance. On the other hand, this increase in stiffness affected pavement behavior adversely which is not desirable for fatigue and low temperature cracking. However, Superpave specifications were still satisfied and asphalt binder’s relaxation properties were improved upon CNT modification. It was eventually found that 0.5% of CNT is the optimum percentage for the best performance.

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