Study on the Impact of Sasobit on Asphalt’s Temperature Susceptibility

2011 ◽  
Vol 477 ◽  
pp. 157-163
Author(s):  
Jie Ji ◽  
Xiao Hui Luo

In order to evaluate the impact of Sasobit on asphalt, the 2%,3%,4% and 5% Sasobit by mass of asphalt are blended into two types of base asphalts (Pen 60/80 and SBS modified asphalt).The mixed asphalt will be called as Sasobit modified asphalt in this study. The 15°C, 25°Cand 30°Cpenetration, the softening point, the 60°C and 135°Cviscosity, the 5°Cductility of Sasobit modified asphalt are tested. The temperature susceptibility of Sasobit modified asphalt is evaluated by using PI, VTS, PVN25-135 and PIR&B. The linear relationships between PI and PIR&B or VTS and PVN25-135 are confirmed. As the addition of Sasobit can differently change the viscosity or rheology of Sasobit modified asphalt under different temperature, it has been shown that the temperature susceptibility of Sasobit modified asphalt become better within the normal temperature range (0°C~50°C) but become higher within the high temperature range (60°C~135°C) as the additive content increases. It has been proved that Sasobit have a different impact of asphalt’s temperature susceptibility at different temperature range. So it is not appropriate to express the temperature susceptibility of Sasobit modified asphalt using a conventional index PI. This study suggests that PI and PVN can be used as indicators of the temperature susceptibility of Sasobit modified asphalt within the normal temperature range and high temperature range respectively.

2013 ◽  
Vol 365-366 ◽  
pp. 978-982
Author(s):  
Xiao Wei Feng ◽  
De Wen Zhang

The softening point of modified asphalt is an extremely important indicator to evaluate the high-temperature performance; its the temperature of modified asphalt sample emerging shear deformation under the action of certain shear stress according to the specific heating rate. Its found that in the actual construction and testing, different temperature conditions has a larger impact on the softening point of the modified asphalt, which has adverse affect on road construction. This paper studied and researched the influence of temperature on modified asphalt softening point indicators from the different test temperature, including packing compact temperature, scraper temperature in removal of asphalt that above test mode, standing temperature, curing temperature and initial heating temperature before test.


2017 ◽  
Vol 902 ◽  
pp. 3-8
Author(s):  
Sen Han ◽  
Pei Sun ◽  
Ya Min Liu ◽  
Wei Li

In order to achieve the penetration method which could reflect the high temperature property of SBS modified asphalt, the paper presented the penetration test of SBS modified asphalt with different types and dosages of SBS modifier at three kinds of penetration weight and four different temperatures. Meanwhile, the high temperature performance of the SBS modified asphalt mixture was studied. It was found that penetration measured under current specification method (25oC, 100g, 5s) could not identify the difference of viscosity and high temperature property of different SBS modified asphalt. When the test conditions are revised to “penetration weight of 150 g, test temperature of 30oC, penetration time of 5s”, the penetration of different SBS modified asphalt measured by revised method could be used to evaluate the temperature susceptibility of SBS modified asphalt accurately and are closely related to the dynamic stability of mixture.


Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 581
Author(s):  
Abdulhakim A. Almajid

This study is focused on the deformation mechanism and behavior of naturally aged 7010 aluminum alloy at elevated temperatures. The specimens were naturally aged for 60 days to reach a saturated hardness state. High-temperature tensile tests for the naturally aged sample were conducted at different temperatures of 573, 623, 673, and 723 K at various strain rates ranging from 5 × 10−5 to 10−2 s−1. The dependency of stress on the strain rate showed a stress exponent, n, of ~6.5 for the low two temperatures and ~4.5 for the high two temperatures. The apparent activation energies of 290 and 165 kJ/mol are observed at the low, and high-temperature range, respectively. These values of activation energies are greater than those of solute/solvent self-diffusion. The stress exponents, n, and activation energy observed are rather high and this indicates the presence of threshold stress. This behavior occurred as a result of the dislocation interaction with the second phase particles that are existed in the alloy at the testing temperatures. The threshold stress decreases in an exponential manner as temperature increases. The true activation energy was computed by incorporating the threshold stress in the power-law relation between the stress and the strain. The magnitude of the true activation energy, Qt dropped to 234 and 102 kJ/mol at the low and high-temperature range, respectively. These values are close to that of diffusion of Zinc in Aluminum and diffusion of Magnesium in Aluminum, respectively. The Zener–Hollomon parameter for the alloy was developed as a function of effective stress. The data in each region (low and high-temperature region) coalescence in a segment line in each region.


2012 ◽  
Vol 178-181 ◽  
pp. 1442-1447 ◽  
Author(s):  
Ai Hong Kang ◽  
Wu Hong Zhang

To explore the relationships between the performances and microstructures of modified asphalt, in the tests, one kind of basic asphalt、two kinds of modifiers and four kinds of modifiers content were selected to prepare modified asphalt. The SBS modified asphalt performances such as softening point, viscosity, Rutting Factor G*/sinδ and the corresponding microstructures with different shearing time were analyzed. The results show that different modifiers have different modification effects on the asphalt,but the change trends of performances and microstructures with the modifier content and shearing time are basically the same. It is also found that there is a good relationship between microstructure and macro performance, the average area of the modifier is closely related to the softening point, total area (or area percentage) and the shape factor of the modifier are suitable to reflect the mechanical behavior of modified asphalts.


1965 ◽  
Vol 8 (10) ◽  
pp. 963-965
Author(s):  
L. M. Golub ◽  
V. E. Finkel'shtein ◽  
E. S. Shpigel'man

2010 ◽  
Vol 663-665 ◽  
pp. 1333-1336
Author(s):  
Xin De Tang ◽  
Xiang Li Kong ◽  
Zhong Guo He ◽  
Jun Li

Microscale flyash/SBS composite modified asphalts (CMA) were prepared by melt blending. Rolling thin film oven test (RTFOT) was employed to study the anti-aging property. Both flyash and SBS disperse homogeneously in the base asphalt, which lead to an improvement in terms of toughness, strength, and thermal stability. Moreover, microscale flyash plays a significant role in the CMA. The effect of flyash on the properties of SBS modified asphalt appears as a decreasing penetration, an increasing softening point, and a decreasing ductility. The anti-deformation ability under high temperature of the CMA improved significantly. In comparison with that of the base asphalt, the softening point of the CMA decreases after aging, which maybe attribute to the different rheological properties between the CMA and the base asphalt. Compared to that of SBS modified asphalt, the anti-aging property of CMA improved significantly. This demonstrates that the microstructure of flyash can prevent oxygen from diffusing and permeating.


Author(s):  
Bilal Dogan ◽  
Robert Ainsworth

There are many similarities between available procedures used for defect assessment. They have been developed as a result of experience gained from material-specific programs and have often been verified using the same data. One recently updated document covering life assessment procedures under creep and creep/fatigue crack growth conditions is BS 7910. This document takes into account some of the most recent developments in the subject, including some from the British Energy R5 Procedure. Future developments in defect assessment procedures will follow the route of simplified and unified codes covering defect behaviour in the low to high temperature range. In this paper, the relevance of the insignificant creep curves in RCC-MR for defect free structures and the creep exemption criteria in BS7910 are examined. Then, an overview is given of some European developments in defect assessment methods for Fitness-for-Service assessment, based on recent and current projects such as the EC thematic network FITNET.


2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Xiangbing Xie ◽  
Tao Hui ◽  
Yaofei Luo ◽  
Han Li ◽  
Guanghui Li ◽  
...  

Strong ultraviolet light and low-temperature are the typical environmental characteristics in high-altitude areas. The performance of SBS-modified asphalt in the above environmental characteristics needs further study. To improve the resistance ultraviolet (UV) ageing and low-temperature performance of copolymer- (SBS-) modified asphalt, an SBS-modified asphalt containing nano-ZnO and nano-TiO2 is proposed. In this paper, nano-ZnO, nano-TiO2, and SBS were used as modifiers with the silane coupling agent (KH-560) as the nanomaterial surface modification. The orthogonal test table was used to analyse the effects of the three modifiers on the physical properties of modified asphalt at different dosages. On this basis, the physical properties, low-temperature properties, and ageing indices (carbonyl index and sulfoxide index) were studied for base asphalt, SBS-modified asphalt, nano-ZnO/SBS-modified asphalt, and nano-ZnO/nano-TiO2/SBS composite-modified asphalt before and after photoaging. The content changes of characteristic elements (Zn and Ti) in the nano-ZnO/nano-TiO2/SBS composite-modified asphalt before and after ageing were studied by scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), and the UV ageing mechanism was revealed. The results indicate that two nanoparticles show the best compatibility with asphalt after surface modification and can improve the binding ability between SBS and base asphalt. The orthogonal test analysis shows that nano-ZnO has a highly significant effect on the low- and high-temperature performance of the nano-ZnO/nano-TiO2/SBS composite-modified asphalt, and nano-TiO2 has a significant effect on the high-temperature performance. Three optimal composite-modified systems for base asphalt including 4% nano-ZnO/1.5% nano-TiO2/3.2% SBS were proposed and had the best antiaging ability. Compared with the sulfoxide index, the carbonyl index changed most obviously before and after ageing. Additionally, the results reveal that nano-TiO2 has a good absorption effect at a wavelength of 365 nm (ultraviolet light), while nano-ZnO is liable to photolysis, and its activity decreases at this wavelength.


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