scholarly journals Influence of Ultraviolet and Oxygen Coupling Aging on Rheological Properties and Functional Group Index of Warm Mix Asphalt Binder

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4216
Author(s):  
Hailian Li ◽  
Peipei Tong ◽  
Xijun Zhang ◽  
Xixiong Lin ◽  
Bo Li
Keyword(s):  
Infrared Spectrum ◽  
Rheological Properties ◽  
Functional Group ◽  
Asphalt Binder ◽  
Group Index ◽  
Uv Aging ◽  
Aging Period ◽  
Before And After ◽  
Time Required ◽  
Peak Value

Warm-mixed asphalt (WMA) has the characteristics of low mixing temperature and energy consumption, which makes it more suitable than hot-mixed asphalt for plateau regions (the altitude is above 500 m, and the terrain is relatively flat or has a wide area with certain undulations). However, WMA is subject to severe ultraviolet (UV) aging because the UV radiation in plateau areas is more intense. The asphalt’s aging changes its rheological properties inevitably, and thus degrades the asphalt pavement’s performance. Accordingly, the purpose of this paper is to investigate the effect of UV and oxygen coupling aging on WMA’s rheological properties and functional group index. Temperature and frequency sweep tests were performed with a dynamic shear rheometer. At the same time, the functional group index was used as an indicator to compare the changes in the WMA’s infrared spectrum before and after UV aging. The results showed that WMA’s elasticity increased and its viscosity decreased after aging with UV. Under the condition of UV–oxygen isolation, as the aging period increased, the WMA’s rutting factor increased gradually. The degree of improvement was greater than that under the condition of oxygen isolation. In contrast, the time required for the WMA’s complex shear modulus to recover under the condition of UV–oxygen coupling was delayed. An increase in the peak value of infrared spectrum indicates that the WMA has undergone oxygen aging. The presence and change in the carbonyl group reflects the degree of the WMA’s UV aging, and the UV aging condition had a greater effect on the peak values of the carbonyl and sulfoxide groups.

Effects of Aging on the Physical and Rheological Properties of Asphalt Binder Incorporating Rediset®

2014 ◽  
Vol 70 (7) ◽  
Author(s):  
Mohamad Yusri Aman ◽  
Zulkurnain Shahadan ◽  
Munzilah Md. Ruhani ◽  
Rosnawati Buhari
Keyword(s):  
Statistical Analysis ◽  
Rheological Properties ◽  
Asphalt Binder ◽  
Dynamic Shear ◽  
Short Term ◽  
Rotational Viscometer ◽  
Aging Index ◽  
Modified Binders ◽  
Before And After ◽  
Effects Of Aging

This paper focuses on physical and rheological properties of virgin asphalt binder blended with different percentage of Rediset® content. The rheological properties of the Rediset® modified binders were characterized before and after being subjected to short-term aging using rotational viscometer (RV) and dynamic shear rheometer (DSR) according to SuperpaveTM test protocols. The results indicated that the penetration and softening point were consistently decreased and increased, respectively for unaged and short-term aged samples. The penetration index (PI) and viscosity aging index (VAI) were increased as the Rediset® modified binders aged and showed a high significance correlation. The addition of Rediset® in asphalt binder exhibited change in binder rheology after subjected to short-term aged which influenced the rutting parameter. A statistical analysis showed that Rediset® used as warm asphalt additive had significantly increased the G*/Sin δ parameter which indicated greater resistance to rutting.

scholarly journals Aging Characteristics of Asphalt Binder under Strong Ultraviolet Irradiation in Northwest China

2021 ◽  
Vol 13 (19) ◽  
pp. 10753
Author(s):  
Ling Zou ◽  
Yan Zhang ◽  
Bangyi Liu
Keyword(s):  
Uv Radiation ◽  
Evaluation System ◽  
Evaluation Method ◽  
Asphalt Binder ◽  
Northwest China ◽  
Gansu Province ◽  
Uv Aging ◽  
Attenuation Index ◽  
Before And After ◽  
Asphalt Performance

Asphalt pavement is significantly affected by ultraviolet (UV) aging. Therefore, the establishment of an asphalt UV aging evaluation system is desirable for highway construction in areas which experience strong UV radiation. In this study, Dunhuang City in Gansu Province (northwest China) was used as the research site. Base and SBS modified asphalts were selected, and their performance changes before and after UV aging were studied. An asphalt UV aging evaluation system was established, including the conditions for an indoor, accelerated UV aging test as well as evaluation indicators. The results showed that the adverse effect of UV aging on asphalt performance was greater than that of RTFOT and PAV, and that the low-temperature performance of asphalt degraded most rapidly. SBS modified asphalt was more resistant to UV aging than base asphalt, while 60/80 pen grade base asphalt was found to be unsuitable for use on pavements which are exposed to strong UV radiation. The residual penetration, penetration attenuation index at 25 °C, and residual ductility of the asphalt were used as indicators to characterize the aging of asphalt, while the fracture energy method was used as a supplementary evaluation method.

scholarly journals Impact of Ultraviolet Radiation on the Aging Properties of SBS-Modified Asphalt Binders

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1111 ◽  
Author(s):  
Huanan Yu ◽  
Xianping Bai ◽  
Guoping Qian ◽  
Hui Wei ◽  
Xiangbing Gong ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Uv Radiation ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Shrinkage Stress ◽  
Uv Aging ◽  
Modified Asphalt ◽  
Aging Properties ◽  
Sbs Modified Asphalt

Styrene Butadiene Styrene (SBS) polymer-modified asphalt binders have become widely used in asphalt pavement because of their advantages in high- and low-temperature performance and fatigue resistance. Asphalt pavement is inevitably exposed to sunlight and ultraviolet (UV) radiation during its construction and service life. However, consideration of the aging effect of UV radiation is still limited in current pavement design and evaluation systems. In order to evaluate the impact of UV radiation on the aging properties of SBS-modified asphalt binders, UV aging tests were performed on Rolling Thin Film Oven Test (RTFOT)-aged samples with different UV radiation intensities and aging times. Sixteen different groups of tests were conducted to compare the rheological properties and functional group characteristics of SBS-modified asphalt binders. Dynamic Shear Rheometer (DSR), Bending Beam Rheometer (BBR), FTIR, and SEM tests were conducted to evaluate the aging mechanisms in various UV aging conditions. The results found that UV radiation seriously destroys the network structure formed by the cross-linking effect in SBS-modified asphalt binders, which aggravates the degradation of SBS and results in a great change of rheological properties after UV aging. The nature of SBS-modified asphalt binder aging resulted from the degradation of SBS and the changes of asphalt binder base composition, which lead to the transformation of colloidal structure and the deterioration of asphalt binder performance. The tests also found that continuous UV radiation can increase shrinkage stress in the asphalt binder surface and leads to surface cracking of the asphalt binder.

Preparation and Properties of Nanoclay/TPS/Asphalt Ternary Binders

2009 ◽  
Vol 620-622 ◽  
pp. 497-500 ◽  
Author(s):  
Shao Peng Wu ◽  
Jin Gang Wang ◽  
Yuan Zhang
Keyword(s):  
Rheological Properties ◽  
High Speed ◽  
Complex Modulus ◽  
Preliminary Investigation ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Frequency Sweep ◽  
Modified Asphalt ◽  
Aging Resistance ◽  
Before And After

After a preliminary investigation on the binary asphalt/clay binder, the ternary binder was prepared by adding the nanoclay and TAFPACK-SUPER (TPS) to the original asphalt. The previous research shows that exfoliated/intercalated layers homogeneously are dispersed in the asphalt matrix and the nanocomposite has formed. Rotation Thin Film Oven Test (RTFOT) and Pressure Age Vessel Test (PAV) results indicate that the modified asphalt with 3% organic nano-montmorillonite (OMMT) present better performance of aging resistance. The purpose of this research is to attain ternary asphalt binder with better rheological performance and aging resistance. The ternary modified asphalt binder containing 4% OMMT and 12% TPS by weight were prepared at the laboratory scale using high speed shearing mixer. The rheological properties of OMMT/TPS modified asphalt binders were evaluated before and after aging in present paper. Temperature sweep tests and frequency sweep tests were conducted to characterize the rheological properties of modified asphalt using Dynamic Shear Rheometer (DSR). According to the frequency sweep tests, complex modulus master curves were plotted to analysis the rheological properties. The results indicate that nanoclay/TPS/asphalt ternary binders have more excellent performance of rheological and aging resistance at both high and low temperatures, compared with the virginal bitumen and TPS modified asphalt.

scholarly journals Aging Properties and Mechanism of Microwave-Activated Crumb Rubber Modified Asphalt Binder

2020 ◽  
Vol 7 ◽  
Author(s):  
Tao Zhou ◽  
Jianing Zhou ◽  
Qidong Li ◽  
Bo Li
Keyword(s):  
Functional Group ◽  
Asphalt Binder ◽  
Molecular Size ◽  
Gel Permeation Chromatography ◽  
Aging Effect ◽  
Microwave Treatment ◽  
Crumb Rubber ◽  
Microwave Activation ◽  
Modified Asphalt ◽  
Before And After

Although crumb rubber modified asphalt (CRMA) has a better performance than matrix asphalt (MA) in road engineering, the application bottlenecks of this material lies in its high viscosity, poor workability and bad storage stability. Microwave technology is one of the solutions to the above problems. The objective of this study was to investigate the physical and chemical changes before and after aging of CRMA which was prepared by microwave activated crumb rubber, and the aging mechanism of microwave-activated crumb rubber modified asphalt (MACRMA). Through penetration, softening point, ductility, viscosity and DSR test, the high and low temperature performance and temperature sensitivity of MA, CRMA and MACRMA before and after aging were studied. These tests results revealed that microwave treatment can improve the anti-rutting ability and the anti-aging performance of rubber asphalt. According to gel permeation chromatography (GPC) test, the distribution changes of the internal molecular content of the three asphalts were determined during the aging process. Its test results showed that aging effect accelerated the conversion of small molecules to large molecules in asphalt, and the value of large molecular size (LMS) increases more after long-term aging. The microwave activation made the swelling reaction more intense, thereby delayed the conversion of LMS in the rubber asphalt. In addition, LMS has a high correlation with test indicators. The fourier transform infrared spectroscopy (FTIR) test was used to measure the functional group changes of each asphalt. The FTIR spectra indicated that microwave activation is mainly a process of physical change. The carbonyl and sulfoxide functional group indices of MACRMA were lower than those of MA and CRMA, which also confirmed that MACRMA has a better anti-aging ability.

Pilot-scale neutralisation of underground mine water

1996 ◽  
Vol 34 (10) ◽  
pp. 141-149 ◽  
Author(s):  
J. P. Maree ◽  
G. J. van Tonder ◽  
P. Millard ◽  
T. C. Erasmus
Keyword(s):  
Mine Water ◽  
Contact Time ◽  
Pilot Scale ◽  
Underground Water ◽  
Underground Mine ◽  
Economic Feasibility ◽  
Fluidised Bed ◽  
Chemical Composition Of Water ◽  
Before And After ◽  
Time Required

Traditionally acid mine water is neutralised with lime (Ca(OH)2). Limestone (CaCO3) is a cheaper alternative for such applications. This paper describes an investigation aimed at demonstrating that underground mine water can be neutralised with limestone in a fluidised-bed. The contact time required between the limestone and the acid water, chemical composition of water before and after treatment, and economic feasibility of the fluidised bed neutralisation process are determined. A pilot plant with a capacity of 10k1/h was operated continuously underground in a gold mine. The underground water could be neutralised effectively using the limestone process. The pH of the water was increased from less than 3 to more than 7, the alkalinity of the treated water was greater than 120 mg/l (as CaCO3) and the contact time required between mine water and limestone was less than 10 min (the exact contact time depends on the limestone surface area). Chemical savings of 56.4% can be achieved compared to neutralisation with lime.

Behaviour of PLA/POSS nanocomposites: Effects of filler content, functional group and copolymer compatibilization

2021 ◽  
pp. 096739112110080
Author(s):  
Yelda Meyva Zeybek ◽  
Cevdet Kaynak
Keyword(s):  
Functional Group ◽  
Filler Content ◽  
Mechanical And Thermal Properties ◽  
Screw Extruder ◽  
Melt Mixing ◽  
Grafted Copolymer ◽  
Before And After ◽  
Twin Screw ◽  
Oligomeric Silsesquioxane ◽  
Matrix Nanocomposites

The main purpose of this study was to investigate influences of three parameters on the mechanical and thermal properties of the polylactide (PLA) matrix nanocomposites filled with polyhedral oligomeric silsesquioxane (POSS) particles. For the first parameter of “Filler Content”, nanocomposites with 1, 3, 5, 7 wt% basic POSS structure were compared. For the second parameter of “Functional Group,” basic POSS structure having only nonpolar isobutyl groups were compared with three other functionalized POSS structures; i.e. aminopropylisobutyl-POSS (ap-POSS), propanediolisobutyl-POSS (pd-POSS) and octasilane-POSS (os-POSS). Finally, for the third parameter of “Copolymer Compatibilization,” all specimens were compared before and after their maleic anhydride (MA) grafted copolymer compatibilization. Specimens were produced with twin-screw extruder melt mixing and shaped under compression molding. Various tests and analyses indicated that the optimum filler content for the improved mechanical properties was 1 wt%; while the optimum structure for strength and modulus was pd-POSS structure, in terms of fracture toughness it was basic POSS structure. Additional use of MA compatibilization was especially effective for the basic POSS and os-POSS particles.

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.

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