Microscale investigation of thin film surface ageing of bitumen

被引:90
作者
Das, P. K. [1 ]
Kringos, N. [1 ]
Birgisson, B. [1 ]
机构
[1] KTH Royal Inst Technol, Div Highway & Railway Engn, S-10044 Stockholm, Sweden
关键词
oxidation; Atomic force microscopy; surface ageing; DSC; UV radiation; bitumen; PHASE-SEPARATION; ASPHALT BINDERS; MORPHOLOGY; RHEOLOGY; MODEL;
D O I
10.1111/jmi.12122
中图分类号
TH742 [显微镜];
学科分类号
摘要
Lay Description This paper investigates the mechanism of bitumen surface ageing which has been investigated utilizing the atomic force microscopy (AFM) and the differential scanning calorimetry (DSC). To do so, three different types of bitumen with different natural wax content were conditioned in four different modes: both UV and air, only UV, only air and without any exposure, for 15 and 30 days. From the AFM investigation after 15 and 30 days of conditioning period, it was found that regardless the bitumen type, the percentage of microstructure on the surface reduced with the degree of exposure and time. Comparing all the four different exposures, it was observed that UV radiation caused more surface ageing than the oxidation. It was also found that the combined effect was not simply a summation or multiplication of the individual effects. The DSC investigation showed that the amount of crystalline fractions in bitumen remain constant even after the systematic conditioning. From the experimental evidence, it could be concluded that the ageing created a thin film upon the exposed surface, which acts as a barrier and creates difficulty for the wax induced microstructures to float up at the surface. Summary This paper investigates the mechanism of bitumen surface ageing, which was validated utilizing the atomic force microscopy and the differential scanning calorimetry. To validate the surface ageing, three different types of bitumen with different natural wax content were conditioned in four different modes: both ultraviolet and air, only ultraviolet, only air and without any exposure, for 15 and 30 days. From the atomic force microscopy investigation after 15 and 30 days of conditioning period, it was found that regardless the bitumen type, the percentage of microstructure on the surface reduced with the degree of exposure and time. Comparing all the four different exposures, it was observed that ultraviolet radiation caused more surface ageing than the oxidation. It was also found that the combined effect was not simply a summation or multiplication of the individual effects. The differential scanning calorimetry investigation showed that the amount of crystalline fractions in bitumen remain constant even after the systematic conditioning. Interestingly, during the cooling cycle, crystallization of wax molecules started earlier for the exposed specimens than the without exposed one. The analysis of the obtained results indicated that the ageing created a thin film upon the exposed surface, which acts as a barrier and creates difficulty for the wax induced microstructures to float up at the surface. From the differential scanning calorimetry analysis, it can be concluded that the ageing product induced impurities in the bitumen matrix, which acts as a promoter in the crystallization process.
引用
收藏
页码:95 / 107
页数:13
相关论文
共 25 条
[1]  
Airey G.D., 2003, INT J PAVEMENT ENG, V4, DOI DOI 10.1080/1029843042000198568
[2]   Binder oxidative aging in Texas pavements - Hardening rates, hardening susceptibilities, and impact of pavement depth [J].
Al-Azri, Nasser A. ;
Jung, Sung Hoon ;
Lunsford, Kevin M. ;
Ferry, Ann ;
Bullin, Jerry A. ;
Davison, Richard R. ;
Glover, Charles J. .
BITUMINOUS MATERIALS AND NONBITUMINOUS COMPONENTS OF BITUMINOUS PAVING MIXTURES 2006, 2006, (1962) :12-20
[3]   Structural Characterization of Micromechanical Properties in Asphalt Using Atomic Force Microscopy [J].
Allen, R. Grover ;
Little, Dallas N. ;
Bhasin, Amit .
JOURNAL OF MATERIALS IN CIVIL ENGINEERING, 2012, 24 (10) :1317-1327
[4]  
[Anonymous], D341812 ASTM
[5]  
Bellitto V., 2012, Atomic Force Microscopy: Imaging, Measuring and Manipulating Surfaces at the Atomic Scale
[6]  
Branthaver J., 1993, SHRPA368, V2
[7]   Micromechanical investigation of phase separation in bitumen by combining atomic force microscopy with differential scanning calorimetry results [J].
Das, Prabir Kumar ;
Kringos, Niki ;
Wallqvist, Viveca ;
Birgisson, Bjorn .
ROAD MATERIALS AND PAVEMENT DESIGN, 2013, 14 :25-37
[8]   High temperature AFM study of CAP 30/45 pen grade bitumen [J].
De Moraes, M. B. ;
Pereira, R. B. ;
Simao, R. A. ;
Leite, L. F. M. .
JOURNAL OF MICROSCOPY, 2010, 239 (01) :46-53
[9]  
Dickinson E.J., 1958, Journal of Applied Chemistry, P673
[10]   The influence of UV aging of a Styrene/Butadiene/Styrene modified bitumen: Comparison between laboratory and on site aging [J].
Durrieu, Francoise ;
Farcas, Fabienne ;
Mouillet, Virginie .
FUEL, 2007, 86 (10-11) :1446-1451