Effect of Asphalt Binder Aging on Thermodynamic Parameters and Its Relationship with Moisture Sensitivity of Asphalt Mixes

2018 ◽  
Vol 30 (11) ◽  
pp. 04018278 ◽  
Author(s):  
Himan Rahmani ◽  
Hamid Shirmohammadi ◽  
Gholam Hossein Hamedi
Keyword(s):  
Thermodynamic Parameters ◽  
Asphalt Binder ◽  
Moisture Sensitivity ◽  
Asphalt Mixes ◽  
Binder Aging

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 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.

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 Recent advances in characterizing the “bee” structures and asphaltene particles in asphalt binders

2020 ◽  
Vol 13 (6) ◽  
pp. 697-706
Author(s):  
Yuhong Wang ◽  
Kecheng Zhao ◽  
Fangjin Li ◽  
Qi Gao ◽  
King Wai Chiu Lai
Keyword(s):  
Near Field ◽  
Asphalt Binder ◽  
Optical Microscope ◽  
Asphalt Binders ◽  
Zero Shear Viscosity ◽  
Surface Features ◽  
Asphaltene Content ◽  
Scanning Transmission ◽  
Before And After ◽  
Binder Aging

AbstractThe microscopic surface features of asphalt binders are extensively reported in existing literature, but relatively fewer studies are performed on the morphology of asphaltene microstructures and cross-examination between the surface features and asphaltenes. This paper reports the findings of investigating six types of asphalt binders at the nanoscale, assisted with atomic force microscopy (AFM) and scanning transmission electron microscopy (STEM). The surface features of the asphalt binders were examined by using AFM before and after being repetitively peeled by a tape. Variations in infrared (IR) absorbance at the wavenumber around 1700 cm−1, which corresponds to ketones, were examined by using an infrared s-SNOM instrument (scattering-type scanning near-field optical microscope). Thin films of asphalt binders were examined by using STEM, and separate asphaltene particles were cross-examined by using both STEM and AFM. In addition, connections between the microstructures and binder’s physicochemical properties were evaluated. The use of both microscopy techniques provide comprehensive and complementary information on the microscopic nature of asphalt binders. It was found that the dynamic viscosities of asphalt binders are predominantly determined by the zero shear viscosity of the corresponding maltenes and asphaltene content. Limited samples also suggest that the unique bee structures are likely related to the growth of asphaltene content during asphalt binder aging process, but more asphalt binders from different crude sources are needed to verify this finding.

Surface Free Energy to Identify Moisture Sensitivity of Materials for Asphalt Mixes

2007 ◽  
Vol 2001 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Amit Bhasin ◽  
Dallas N. Little ◽  
Kamilla L. Vasconcelos ◽  
Eyad Masad
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Moisture Sensitivity ◽  
Asphalt Mixes

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.

scholarly journals Balancing the Performance and Environmental Concerns of Used Motor Oil as Rejuvenator in Asphalt Mixes

Recycling ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 11 ◽  
Author(s):  
Eslam Deef-Allah ◽  
Magdy Abdelrahman ◽  
Mark Fitch ◽  
Mohyeldin Ragab ◽  
Mousumi Bose ◽  
...  
Keyword(s):  
Environmental Protection Agency ◽  
Asphalt Binder ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Environmental Concerns ◽  
Ethyl Benzene ◽  
Motor Oil ◽  
Asphalt Mixes ◽  
Used Motor Oil ◽  
The Us

Road deterioration inspires researchers to enhance the properties of asphalt binder for better performing mixes. Recycled tire rubber, or crumb rubber modifier (CRM), and used motor oil (UMO) are two modifiers that enhance asphalt binder performance through two different mechanisms. CRM affects high-temperature properties while UMO modifies low-temperature properties. Potential environmental concerns arising from the use of UMO have been raised in the literature. In this paper, the two recycled materials were investigated for their ability to complement each other. Both performance benefits of using both materials and the environmental concerns of using UMO were studied. Four CRM asphalt binders were investigated: two with UMO and two without UMO. Environmental impacts were evaluated using gas chromatography to check air emissions for benzene, toluene, ethyl-benzene, and xylenes (BTEX). The potential for toxic leaching of elements from modified hot mix asphalt (HMA) were checked using the US Environmental Protection Agency (EPA) Toxicity Characteristic Leaching Protocol (TCLP). For asphalt binders modified by CRM-UMO combinations, CRM decreased the amounts of released BTEX components, presumably by absorbing UMO and slowing the release of BTEX. Leaching results concluded that UMO mixtures showed a notable percentage of sulfur (S) as compared to non-UMO mixes. All these leachate components were under EPA limits.

scholarly journals Evaluating the Surface Free Energy and Moisture Sensitivity of Warm Mix Asphalt Binders Using Dynamic Contact Angle

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Muhammad Rafiq Kakar ◽  
Meor Othman Hamzah ◽  
Mohammad Nishat Akhtar ◽  
Junita Mohamad Saleh
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Hot Mix Asphalt ◽  
Asphalt Binder ◽  
Moisture Damage ◽  
Warm Mix Asphalt ◽  
Work Of Adhesion ◽  
Moisture Sensitivity ◽  
Modified Binders ◽  
Production Temperature

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.

Sign in / Sign up

Export Citation Format

Share Document