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 Kinetics of Saudi Arabian Paving Asphalt

Abstract

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.     

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.     

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。     

A Study on Antiaging Performances of Two Paving Asphalts

Abstract

In this article, the processes of Anshan oxidizing paving asphalts have been studied and the kinetic models for two paving asphalts were put forward. Based on the change of service performances, viscidity, and Gastel index (Ic), the aging resistance of the two asphalts have been compared. Meanwhile, the aging mechanism also has been investigated. The results show that the presented dynamics models can be used to describe the aging velocity for the two asphalts perfectly. According to dx/dt(AH-90) > dx/dt(AH-70), it can prove that the aging resistance of AH-70 is better than that of AH-90. After aging, the change of both penetration and softening point of AH-70 are lower than that of the corresponding parameters of AH-90, and the aging index of AH-70 is also lower than that of AH-90, which proves that the aging resistance of AH-70 is better than that of AH-90. During aging, every composition tends to be transformed into the heavier one. As a result, the asphltene content increases, the original colloidal structure of asphalt is destroyed to deteriorate paving performances of the asphalt.     

A Study on Aging Kinetics of Asphalt Based on Softening Point

Abstract

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.     

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.     

Study on Aging Kinetics of Panjin Paving Asphalt

In this paper, the changes of n-pentane asphaltene content, penetration, softening point, and ductility of two Panjin paving asphalts have been studied during aging. Further, based on the change of n-pentane asphaltene content, a study on aging kinetics of asphalt has been conducted. Some correlative kinetic parameters were calculated, and the aging kinetic equation of asphalt was gained. The value calculated, depending on the equation, was in accordance with the experimental data. In addition, 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. Moreover, the kinetic model was proved to be reliable by investigating the changes of penetration, softening point, and ductility of asphalt during aging.     

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。     

SBS改善道路沥青及沥青混合料性能的研究

以欢喜岭AH-90、日本-110沥青为基料,分别加入6%的燕山牌SBS-2改性剂制成的改性沥青,其针入度指数PI、高低温性能,弹性恢复性能,老化性能均得以提高,建议SBS-2最佳掺加量：国产重交基质沥青为4%-6%,进口基质沥青为4%-5%。     

PREPARATION OF HEAVY PAVING ASPHALT BY BLENDING–OXIDIZING ANSHAN VACUUM RESIDUE AND THE EVALUATION OF ITS PAVING PERFORMANCE

ABSTRACT

In this paper, various brand heavy paving asphalts conforming to GB/T15180-94 standard have been prepared by blending–oxidizing Anshan vacuum residue, and their pavement performances have been evaluated. The laboratory test shows that the prepared AH-70 and AH-90 has the characteristics of good temperature susceptibility, good high-temperature stability and good low-temperature cracking resistance. The mathematic model of the relationship between penetration, softening point of the asphalt and the blender content has been set up and, the relationship between penetration, softening point and the oxidation time has been found. Those mathematic models built by gradual regression of the experiment data can be used to determine the adding amount of the two blenders. Fan daobo experiential equation, which described the relationship between softening point of the paving asphalt and its compositions, has been corrected and the corrected equation is more suitable for the prepared paving asphalts than Fan daobo experiential equation.     

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.     

Influence of Chemical Composition on the Physical Characteristics of Paving Asphalts

Abstract

The simplest general compositional model considers asphalt to be made up of asphaltenes, heavy oils, and resins. In the present study the extent of similarity between the properties and composition of various types of asphalt obtained from different sources has been carefully explored. It shows how ductility, penetration, and softening point are related to the chemical nature of paving asphalts in the range 41–58 softening points. Asphalt properties are found to be a direct function of its chemical constituents. The relationship between softening point and asphaltene content was found to be linear while asphalts of the same softening point are easily distinguished by the content of the resins. Evaluation of the two asphalt indices—the asphaltene index (I _A ) and the Gaestel index (I _C ), reveals that they both vary linearly with the composition of asphaltenes and resins thus confirming their suitability in the characterization of asphalts. Comparison of the two indices shows that IC is more suitable in estimating the colloidal stability of different groups of asphalts. The observed correlations can be found useful in the areas of asphalt blending and rejuvenating through the appropriate selection of asphalt components.     

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.     

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.     

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.     

Influence of Chemical Composition on the Physical Characteristics of Paving Asphalts

The simplest general compositional model considers asphalt to be made up of asphaltenes, heavy oils, and resins. In the present study the extent of similarity between the properties and composition of various types of asphalt obtained from different sources has been carefully explored. It shows how ductility, penetration, and softening point are related to the chemical nature of paving asphalts in the range 41-58 softening points. Asphalt properties are found to be a direct function of its chemical constituents. The relationship between softening point and asphaltene content was found to be linear while asphalts of the same softening point are easily distinguished by the content of the resins. Evaluation of the two asphalt indices—the asphaltene index (I_A) and the Gaestel index (I_C), reveals that they both vary linearly with the composition of asphaltenes and resins thus confirming their suitability in the characterization of asphalts. Comparison of the two indices shows that IC is more suitable in estimating the colloidal stability of different groups of asphalts. The observed correlations can be found useful in the areas of asphalt blending and rejuvenating through the appropriate selection of asphalt components.     

道路沥青及SBS改性沥青的紫外老化研究

采用紫外辐射试验对道路沥青和SBS改性沥青进行加速老化试验研究.利用老化前后的软化点、针八度、延度和四组分变化。分析了道路沥青的紫外线老化机理。结果表明:随紫外线老化时间的延长,道路沥青和SBS改性沥青软化点呈上升趋势、针入度和延度呈降低变化趋势,其中又以延度变化最为明显。经紫外线老化后道路沥青和SBS改性沥青的四组分也有变化,其中沥青质略微上升、芳香分略微降低,而饱和分和胶质变化不大。     

PREPARATION OF HEAVY PAVING ASPHALT BY BLENDING-OXIDIZING ANSHAN VACUUM RESIDUE AND THE EVALUATION OF ITS PAVING PERFORMANCE

In this paper, various brand heavy paving asphalts conforming to GB/T15180-94 standard have been prepared by blending-oxidizing Anshan vacuum residue, and their pavement performances have been evaluated. The laboratory test shows that the prepared AH-70 and AH-90 has the characteristics of good temperature susceptibility, good high-temperature stability and good low-temperature cracking resistance. The mathematic model of the relationship between penetration, softening point of the asphalt and the blender content has been set up and, the relationship between penetration, softening point and the oxidation time has been found. Those mathematic models built by gradual regression of the experiment data can be used to determine the adding amount of the two blenders. Fan daobo experiential equation, which described the relationship between softening point of the paving asphalt and its compositions, has been corrected and the corrected equation is more suitable for the prepared paving asphalts than Fan daobo experiential equation.     

A STUDY ON AGING KINETICS OF ANSHAN PAVING ASPHALT

ABSTRACT

The aging processes of two Anshan paving asphalts conforming to GB/T15180-94 standard have been studied by Rotation Thin Film Oven Test (RTFOT) and the aging kinetic models of two paving asphalts have been determined. The results show that the aging of the prepared paving asphalt is a first order reaction. The viscosity of the asphalt increases gradually with the aging time. The greater the aging index is, the more easily the asphalt is aged. Because the chains break down to form free radicals, oxidation reactions occur. The aging resistance of the asphalt with lower aromaticity and with less aromatic cycle numbers is weak.