Effect of ozonation and strong UV radiation on the rheological properties of atmospheric resid and liquid asphalt

1999 ◽  
Vol 35 (5) ◽  
pp. 308-314 ◽  
Author(s):  
N. M. Likhterova ◽  
V. V. Lunin ◽  
V. N. Torkhovskii ◽  
V. K. Frantsuzov ◽  
O. N. Kalinicheva
Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1111 ◽  
Author(s):  
Huanan Yu ◽  
Xianping Bai ◽  
Guoping Qian ◽  
Hui Wei ◽  
Xiangbing Gong ◽  
...  

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.


Author(s):  
Wilmar Darío Fernández Gómez ◽  
◽  
Hugo Alexander Rondón Quintana ◽  
Fredy Alberto Reyes Lizcano ◽  
◽  
...  

2008 ◽  
Vol 385-387 ◽  
pp. 481-484
Author(s):  
Shao Peng Wu ◽  
Ling Pang ◽  
Guo Jun Zhu

Asphalt ageing induced by heat, oxidation and ultraviolet (UV) radiation was investigated using various laboratory simulation ageing methods and outdoor ageing. One normal 70 penetration asphalt and its styrene-butadiene-styrene (SBS) modified asphalt were employed to assess the changes in chemical and rheological properties by infrared spectroscopy and dynamic shear rheometer under various ageing conditions, thus the relationship among rolling thin-film oven(RTFO), pressurized ageing vessel (PAV) and UV radiation ageing was distinguished. Experimental results showed that photodegradation caused by outdoor exposure UV ageing of 50~200µm thin films for a month, was found to be the most severe, following by PAV and then RTFO with respects to rehological and chemical changes. Photodegradation effect decreased as the thickness of asphalt film increases. Dynamic shear tests indicated that polymer networks were gradually destroyed during ageing, but the aged SBS modified asphalts still displayed better rheological properties than the corresponding base asphalt. The weight percent of oxygen as carbonyl increased and of SBS as butadiene decreased after ageing based on infrared spectrums. However, chemical and rheological changes were not generally consistent, and ageing susceptibility may be ranked differently when different evaluation methods were used.


2017 ◽  
Vol 240 ◽  
pp. 597-603 ◽  
Author(s):  
Barış Demirbay ◽  
A. Ata Ayhan ◽  
Nuran Cereyan ◽  
Can Akaoğlu ◽  
İlke Ulusaraç ◽  
...  

Author(s):  
J. Hanker ◽  
B. Giammara ◽  
G. Strauss

Only a fraction of the UV radiation emitted by the sun reaches the earth; most of the UVB (290-320nm) is eliminated by stratospheric ozone. There is increasing concern, however, that man-made chemicals are damaging this ozone layer. Although the effects of UV on DNA or as a carcinogen are widely known, preleukemia and acute myeloid leukemia (AML) have only rarely been reported in psoriasis patients treated with 8-methoxypsoralen and UV (PUVA). It was therefore of interest to study the effects of UV on the myeloperoxidase (MP) activity of human neutrophils. The peroxidase activity of enriched leukocyte preparations on coverslips was shown cytochemically with a diaminobenzidine medium and cupric nitrate intensification.Control samples (Figs. 1,4,5) of human bloods that were not specifically exposed to UV radiation or light except during routine handling were compared with samples which had been exposed in one of several different ways. One preparation (Fig. 2) was from a psoriasis patient who had received whole-body UVB phototherapy repeatedly.


2020 ◽  
Vol 29 (12) ◽  
pp. 52-58
Author(s):  
E.P. Meleshkina ◽  
◽  
S.N. Kolomiets ◽  
A.S. Cheskidova ◽  
◽  
...  

Objectively and reliably determined indicators of rheological properties of the dough were identified using the alveograph device to create a system of classifications of wheat and flour from it for the intended purpose in the future. The analysis of the relationship of standardized quality indicators, as well as newly developed indicators for identifying them, differentiating the quality of wheat flour for the intended purpose, i.e. for finished products. To do this, we use mathematical statistics methods.


Author(s):  
Maria Szcześniak ◽  
◽  
Bożena Grimling ◽  
Jan Meler ◽  
Bożena Karolewicz

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