Aging Behavior of Colored Paving Asphalt

In this paper, the aging processes of colored paving asphalt conforming to GB/15180-94 standard were studied by rotate thin film oven (RTFO) test. The results show that the established two dynamics models can be use to describe the aging velocity of the two kinds of colored paving asphalt perfectly. After aging, asphaltene content increased, resins and aromatics content, as well as saturate content decreased. As a result, the original colloidal structure of colored paving asphalt is destroyed, which deteriorates performance of the colored paving asphalt. During aging, the Gastel index (Ic), which is sensitive to aging conditions, decreased with increase of aging temperature and extension of aging time. Therefore, the Gastel index can be used to evaluate the aging resistance of the colored paving asphalt.     

紫外线添加剂对沥青紫外线老化的改善作用

采用沥青薄膜烘箱试验（TFOT）和紫外线老化试验，对壳牌90号重交通道路石油沥青，以及掺加添加剂后沥青的针入度、软化点、延度和粘度等指标进行了试验研究。试验结果表明，紫外线老化对沥青性能有比较明显的影响作用，但掺加合适剂量的某些添加剂后，沥青性能可以在一定程度上得到改善；此外，通过TFOT还表明紫外线添加剂对沥青热老化也有一定的改善作用。     

Aging of Flame Retardant Asphalt

Abstract

Weight-loss coefficient method and aging index method were employed to investigate and compare the anti-aging performance of two different kinds of flame-retardant asphalt samples (FR-70 and FR-90) prepared by Liaoning University of Petroleum & Chemical Technology. The results showed that at certain temperatures the weight-loss method of FR-70 was better than that of FR-90 as a whole, which indicates that anti-aging performance of FR-70 was better that of FR-90. At the same aging temperature, aging index of FR-70 asphalt was less than that of FR-90, viz. the anti-aging performance of FR-70 was better than that of FR-90. The consistent experimental results from the two methods showed that these two methods are reliable when investigating the anti-aging performance of flame retardant asphalt.     

苯乙烯焦油对橡胶改性沥青性能的影响

实验以辽河油田生产的沥青为原料,加入橡胶粉和苯乙烯焦油,以高速剪切法制备改性沥青。考察了橡胶粉和苯乙烯焦油对沥青性能的影响,并对改性沥青进行老化实验。确定最佳橡胶粉质量分为15%,并向质量分数为15%橡胶改性沥青中加入苯乙烯焦油,使橡胶粉可在沥青中充分溶胀,提高橡胶沥青的使用性能。实验表明,苯乙烯焦油的加入可提高橡胶改性沥青的性能,此时沥青的软化点可达39.7℃,沥青的针入度可以达11(0.1mm),延度为121cm,符合140号道路沥青标准。老化实验表明,改性沥青老化后橡胶粉有聚结和析出。     

道路废旧沥青混合料的再生及理化性质研究

以辽河AH-90高升工地沥青为补充沥青,选用LKJ-Ⅱ型废旧沥青再生剂,对道路废旧沥青混合料进行再生,分析测定了再生沥青的理化性质及抗老化性质。结果表明,再生剂/补充沥青/废旧沥青优选适宜配比为9:10:100(质量比),所制备再生沥青的主要理化性质符合JTG F 40—2004标准要求;再生沥青于163℃薄膜烘箱中,经5 h老化后质量损失率为0.62%。     

NMR Fingerprinting of Chemical Changes in Asphalt Fractions on Oxidation

Abstract

The composition of asphalt has been the subject of much study because such data are required in determining its performance-related properties. A problem inherent in studying asphalt composition is its chemical complexity; however, the characterization of asphalt can be better achieved by separating into fractions. In this work, the chemical property of commercial-grade asphalt obtained from BAPCO refinery, Bahrain (BH), was carried out. The rolling thin-film oven (RTFO), used for short-term aging, and pressurized aging vessel (PAV), used for long-term aging, ASTM D4124 (1991) method was used to separate fresh and aged asphalt into four generic fractions such as asphaltenes, polar aromatics, naphthene aromatics, and saturates. The Corbett fractionation procedure was used to separate fresh and aged asphalt into four generic fractions such as asphaltenes, polar aromatics, naphthene aromatics, and saturates. Nuclear magnetic resonance (NMR) was employed to fingerprint the chemical changes that occurred in asphalt during the aging processes. NMR measurements of asphalt fractions showed that during aging, isomerization and dehydrogenation types of reactions took place. Significant differences were observed between the structure and composition of fresh and aged fractions of asphalt. Results from NMR spectrometry provided significant information concerning the chemical transformations that occurred during the aging processes.     

The Aging Resistance of Asphalt Containing a Compound of LDHs and Antioxidant

Effects of layered double hydroxides (LDHs), antioxidant (Irganox 1010) and their compounds on physical and rheological properties and chemical compositions of asphalt were investigated to evaluate the antiaging performance. Results indicate that Irganox 1010 modified asphalt shows good thermo-oxidative aging resistance, LDHs modified asphalt shows good ultraviolet (UV) aging resistance, while the compound consisting of LDHs and Irganox 1010 modified asphalt exhibits excellent resistance to both thermo-oxidative aging and UV aging. Furthermore, changes of chemical compositions of asphalt show that Irganox 1010 peptizes the asphaltenes, and the compound of LDHs and Irganox 1010 exhibits the most effective inhibition of gelatinization of asphalt binder during aging process.     

Changes in rheological properties during asphalt aging

The deterioration of asphalt binders rheological behaviors in different aging stages were investigated by using self-developed indoor aging equipment SAT (simple aging test), and the corresponding relationship between indoor simulated aging and field asphalt aging was established. It was found that SAT equipment can better simulate the aging process of asphalt on site, with asphalt film thickness of 2?mm, short-term aging temperature at 150?°C, long-term aging temperature at 95?°C.     

Study on Aging Capability of Paving Asphalt

The changes of softening point, penetration, and ductility of two asphalts after aging were studied. Two methods are simultaneously used to study the aging kinetics of two asphalts and some kinetic parameters are given in this paper. The results show that the softening points increase while penetration and ductility values decrease after aging. It was concluded that the aging capability of AH-70 asphalt is better than AH-90 asphalt. The aging kinetic models of two asphalts based on softening points are compared with a pentane asphaltene aging kinetic model and the results are consistent. A new and easy method for studying the aging of asphalt was developed.     

Study on Aging Capability of Paving Asphalt

Abstract:

The changes of softening point, penetration, and ductility of two asphalts after aging were studied. Two methods are simultaneously used to study the aging kinetics of two asphalts and some kinetic parameters are given in this paper. The results show that the softening points increase while penetration and ductility values decrease after aging. It was concluded that the aging capability of AH-70 asphalt is better than AH-90 asphalt. The aging kinetic models of two asphalts based on softening points are compared with a pentane asphaltene aging kinetic model and the results are consistent. A new and easy method for studying the aging of asphalt was developed.     

Aging Performance of SBS Modified Asphalt

Abstract

The penetration, softening point, and ductility of the aging basic asphalt and styrene-butadiene-styrene (SBS) modified asphalt were studied, and the thin film oven aging behavior of them was researched by using infrared spectrum. The experimental results showed that the softening point was increased, the penetration and ductility were decreased after basic asphalt thin film oven aging; the results of aging SBS modified asphalt thin film oven aging was similar too. The research of infrared spectrum indicated that absorbing–oxygen oxidation reaction was taking place when basic asphalt film was aging, carbonyl and sulfoxide groups were increased after SBS modified asphalt thin film oven had been aging. The aging extent of SBS modified asphalt was bigger than basic asphalt and the ability of bearing low temperature was better. SBS modified asphalt could have worse anti-aging performances than that of base asphalt.     

Effect of thermochromic materials on physical and aging properties of SBS modified asphalt

Abstract

The effects of different types (red, black and blue color) and content (2% and 4%) of thermochromic powders on aging properties of styrene-butadiene-styrene copolymer (SBS) modified asphalt were investigated. Physical properties of the binders (ductility, penetration, viscosity and softening point) were tested before and after thermal-oxidative and ultraviolet radiation aging. The results showed thermochromic powders improved the deformability and weakened the high-temperature performance of SBS modified asphalt to some extent. Thermochromic powders could obviously improve the anti-aging properties of SBS modified asphalt. In addition, SBS modified asphalt with 2% thermochromic materials showed the best aging resistance under all aging modes.     

道路沥青老化动力学的研究--以软化点为参数建立沥青老化动力学模型

研究了以辽河油田生产的稠油为基质沥青自制的两种沥青老化后软化点的变化，以软化点为参数建立了沥青一级老化动力学模型。并用该动力学模型对这两种沥青的抗老化性能进行了研究，求得了动力学参数。实验结果表明，这两种沥青老化后软化点均升高，AH-70沥青抗老化性能优于AH-90沥青，以软化点为参数建立的沥青老化动力学模型较好地表征了沥青老化过程，为研究沥青老化提供了一种简便可行的分析方法。     

塔河原油所产道路沥青抗老化性能研究

分析了高沥青质塔河原油减压渣油生产道路沥青的潜在优势和不足,认为主要问题是所产道路沥青的抗老化性能较差和延度较低.研究了塔河减压渣油所产道路沥青的老化过程动力学,结果表明,该道路沥青老化时,活化能较低、反应速率常数较高,老化前后沥青各项指标变化幅度较大,表现出沥青的抗老化性能差.通过对沥青老化机理的分析,认为可采用组分调合、部分改性及添加抗老化添加剂的方法来解决延度低、抗老化性能差的问题.试验数据表明,利用上述方法,可以使塔河原油所产道路沥青的延度和抗老化性能得到改善,主要技术指标符合优质产品规格要求.     

高等级道路沥青老化动力学研究

在实验室研究了AH－70和AH－90两种高等级道路沥青在老化过程中,正戊烷沥青质及针入度、软化点、延度等指标的变化,并根据老化过程中,正戊烷沥青质的变化,进行了沥青老化动力学研究,计算得出了有关动力学参数,得到了沥青老化动力学方程,其计算值与试验数据相吻合。表明高等级道路沥青老化属于一级动力学反应。实际老化过程中针入度、软化点及延度的变化进一步证明了所得动力学模型是可靠的。     

再生沥青路用性能的室内研究

在实验室采用粘温指数法、失重系数法和老化指数法分别考察了沈阳—铁岭(沈铁)、沈阳—本溪(沈本)公路段再生沥青及其原沥青辽河AH90的感温性能和抗老化性能,结果表明,它们的温度敏感性由弱到强的顺序为辽河AH90沥青<沈铁再生沥青<沈本再生沥青,但相差不大,表明废旧沥青的再生效果较为理想;用沈铁再生沥青混合料分别进行马歇尔稳定度试验、浸水马歇尔试验和冻融劈裂试验,考察其马歇尔稳定度、残留稳定度和冻融劈裂残留强度比,结果表明,沈铁再生沥青混合料与辽河沥青相比没有明显变化,能完全满足应用要求。     

A Study on the Aging Kinetics of PPA Modified Asphalt

Abstract

Asphalt binders have been chemically modified with polyphosphoric acid (PPA) since the early 1970s. A large number of research papers have shown that the addition of PPA to asphalt improved the high-temperature stability and rheological properties of asphalt. In this article, research on the aging kinetics of PPA-modified asphalt was carried out based on determining the softening point of asphalts at different aging time and temperatures. The results showed that the aging reaction of PPA-modified asphalt followed the first-order reaction; the aging reaction rate of PPA-modified asphalt was lower than that of original asphalt; the activation energy of PPA-modified asphalt was higher than that of original asphalt; and the anti-aging performance of PPA-modified asphalt was better than that of original asphalt.     

Study on Aging Kinetics of Saudi Arabian Paving Asphalt

The changes of n-pentane asphaltene content, penetration, softening point, and ductility of two Saudi Arabian paving asphalts have been studied during aging. Further, aging kinetics of asphalt, based on the change of n-pentane asphaltene content, has been studied. Some correlative kinetic parameters were calculated and the aging kinetics equation of asphalt was gained. The value calculated depending on the equation was in accordance with the experimental data. And the relationship between the composition of the high grade paving asphalt and its aging resistant performances was revealed. It showed that the aging of high grade paving asphalt was a first-order reaction. AH-70 paving asphalt has the following characteristics: higher reaction active energy, less reaction velocity constant, lower aging velocity, and better aging resistance performance compared with AH-90 paving asphalt. The changes of penetration, softening point, and ductility of asphalt during aging further proved that the kinetic model is reliable.     

生物柴油残渣对老化沥青物理性能的影响

利用生产生物柴油的残渣,经过物理分馏、冷凝过程获取可恢复老化沥青性能的生物再生剂。选择50号基质沥青进行短期老化试验,以沥青的针入度、软化点、延度为检验标准,发现添加生物再生剂的老化沥青性能可恢复到老化前标准;设定使再生沥青针入度恢复到50 1/10 mm的生物沥青掺量为最佳掺量,通过动态剪切试验(DSR)和沥青小梁弯曲试验(BBR)发现在最佳掺量条件下,再生沥青的高温抗变形能力和低温抗裂性均优于原50号基质沥青;与老化沥青相比,再生沥青高温抗变形能力略有下降,低温抗裂性大幅提高,证实了生物柴油残渣作为老化沥青再生剂的可行性。     

A Study on Aging Kinetics of Asphalt Based on Softening Point

Asphalt aging is a nonreversible first order reaction, and the extent of asphalt aging is usually expressed by the increase of its softening point. In this article, the first order aging kinetic model of asphalt has been put forward based on softening points of asphalt at different aging time, and the kinetic parameters have been obtained. The results showed that the aging of asphalt could be described with softening point and belonged to first order kinetics, which offered a available and convenient method for studying the asphalt aging behavior. The aging resistance of two paving asphalts were also compared by this model.