Study on Composition and Structure of Liaoshu Asphalt

Abstract

In this article, the structure characteristics of Liaoshu paving asphalts have been studied by the methods of element analysis, SARA and E-D-M. At same time, the relation between composition and structure and using performance of Liaoshu paving asphalt were established. The experimental results show that carbon and hydrogen contents were more than 95%, the hydrogen/carbon atom ratio was about 1.5 in the Liaoshu paving asphalts. The content of saturates is between 20 and 25% in the Liaoshu paving asphalt, aromatics 35–40%, resin 25–30%, and asphaltene 8–10%. There are 45 carbon atoms in asphalt average molecule, which contain 16–17 aromatic carbon atoms. The number of total ring in asphalt average molecule is 5–6, the aromatic ring is 3–4, the naphthene ring is 1–2.     

Study on Composition and Structure of Liaoshu Asphalt

In this article, the structure characteristics of Liaoshu paving asphalts have been studied by the methods of element analysis, SARA and E-D-M. At same time, the relation between composition and structure and using performance of Liaoshu paving asphalt were established. The experimental results show that carbon and hydrogen contents were more than 95%, the hydrogen/carbon atom ratio was about 1.5 in the Liaoshu paving asphalts. The content of saturates is between 20 and 25% in the Liaoshu paving asphalt, aromatics 35 and 40%, resin 25 and 30%, and asphaltene 8 and 10%. There are 45 carbon atoms in the average asphalt molecule, which contain 16-17 aromatic carbon atoms. The number of total ring in the average asphalt molecule is 5-6, the aromatic ring is 3-4, and the naphthene ring is 1-2.     

Study on Composition and Structure of Liaoshu Asphalt

In this article, the structure characteristics of Liaoshu paving asphalts have been studied by the methods of element analysis, SARA and E-D-M. At same time, the relation between composition and structure and using performance of Liaoshu paving asphalt were established. The experimental results show that carbon and hydrogen contents were more than 95%, the hydrogen/carbon atom ratio was about 1.5 in the Liaoshu paving asphalts. The content of saturates is between 20 and 25% in the Liaoshu paving asphalt, aromatics 35-40%, resin 25-30%, and asphaltene 8-10%. There are 45 carbon atoms in asphalt average molecule, which contain 16-17 aromatic carbon atoms. The number of total ring in asphalt average molecule is 5-6, the aromatic ring is 3-4, the naphthene ring is 1-2.     

用辽河高粘原油生产重交通道路沥青的研究——（Ⅲ）辽曙沥青组成与结构分析

利用元素分析,族组成分析和结构族组成分析方法,研究了辽曙沥青的组成与结构,建立了辽曙沥青组成与结构和使用性能之间的关系。辽曙沥青碳氢含量在95%以上,氢碳原子比在1.5左右;辽曙沥青平均分子全部是多环结构,每个平均分子中的含有45个碳原子,其中芳碳数为16-17个,总环数为5-6个,其中芳环数为3-4个,辽曙沥青的沥青质含量在8%-10%之间,胶质含量在25%-30%之间,芳香分含量在35%-40%之间,饮和分含量在20%-25%之间的族组成使沥青具有良好的性能。     

Study and Evaluation of Aging Performance of Petroleum Asphalts and Their Constituents During Oxygen Absorption. III. Average Molecular Structure Parameter Changes

Abstract

The changes of the structural parameters of the average molecules of Chinese Shanjiasi and Shengli petroleum asphalts and their constituents during oxygen absorption were studied based on the oxygen absorption behaviors and the chemical group composition and structure changes. The results show that all the structural parameters of the average molecules of asphalts and their constituents increase clearly after oxygen absorption with the exceptions of the naphthene carbon rates and the paraffin carbon rates. The parameters include the total carbon numbers, the aromatic carbon numbers, the naphthene carbon numbers, the paraffin carbon numbers, the total ring numbers, the aromatic ring numbers, the naphthene ring numbers, the total hydrogen numbers, the aromaticities, and the concentration indexes. The most obvious are the structural parameter changes of the average molecules of the asphalt resin and asphaltene constituents. The structural parameter changes of the average molecules of Shengli asphalt and its constituents are remarkably greater than those of Shanjiasi asphalt and its constituents. The clearer changes of all the average molecular structure parameters of SHL asphalt resin and asphaltene, especially resin could possibly be one of the key factors leading to the much clearer deterioration of the colloidal stability and the serviceability than SJS asphalt in oxygen absorption.     

Study and Evaluation of Aging Performance of Petroleum Asphalts and Their Constituents During Oxygen Absorption. III. Average Molecular Structure Parameter Changes

The changes of the structural parameters of the average molecules of Chinese Shanjiasi and Shengli petroleum asphalts and their constituents during oxygen absorption were studied based on the oxygen absorption behaviors and the chemical group composition and structure changes. The results show that all the structural parameters of the average molecules of asphalts and their constituents increase clearly after oxygen absorption with the exceptions of the naphthene carbon rates and the paraffin carbon rates. The parameters include the total carbon numbers, the aromatic carbon numbers, the naphthene carbon numbers, the paraffin carbon numbers, the total ring numbers, the aromatic ring numbers, the naphthene ring numbers, the total hydrogen numbers, the aromaticities, and the concentration indexes. The most obvious are the structural parameter changes of the average molecules of the asphalt resin and asphaltene constituents. The structural parameter changes of the average molecules of Shengli asphalt and its constituents are remarkably greater than those of Shanjiasi asphalt and its constituents. The clearer changes of all the average molecular structure parameters of SHL asphalt resin and asphaltene, especially resin could possibly be one of the key factors leading to the much clearer deterioration of the colloidal stability and the serviceability than SJS asphalt in oxygen absorption.     

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.     

THE STUDY OF PRODUCING HEAVY TRAFFIC ASPHALT BY USING THE HIGH VISCOUS CRUDE FROM NO.l SHUGUANG ZONE OF LIAOHE OIL FIELD

ABSTRACT

The characteristics of the high viscous crude from No. 1 Shuguang Zone of Liaohe Oil Field are similar to those of residue distillates of general crude such as high density(ρ ₂₀=0·9977 g.cm^-3),high viscidity υ ₁₀₀= 1223·9 mm².s-¹) and high carbon/hydrogen ratio. This oil contains less wax, but rich in resin and asphalt, which belongs to low sulfur naphthene-base crude oil and can be used as feedstock to produce high paving asphalt. But now it is used as fuel after emulsificating. In order to make full use of this oil and resolve the problem of paving asphalt demand-supply, various paving asphalts conforming to GB50092-96 standard were produced by blending vacuum residue of the high viscous crude from No.l Shuguang Zone of Liaohe Oil Field and waste oil which is rich in aromatics and poor in wax. The laboratory test results show that modified paving asphalts have good low-temperature properties and antiaging feature.     

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.     

Application of Solubility Parameter Theory in Evaluating the Aging Resistance of Paving Asphalts

Abstract

In this article, asphaltene index, aging index, and Gastel index (Ic) are introduced to study the aging resistance of paving asphalts. Meanwhile, the solubility parameter theory is applied to evaluate the aging resistance of these paving asphalts. The results show that the greater the asphaltene index, the aging index or the Gastel index, the worse the aging resistance of the paving asphalt. The small difference between solubility parameters of asphaltene and maltene of the paving asphalt contributes to its good aging resistance. The analytical results in these two ways are consistent.     

Effect of Chemical Nature on the Susceptibility of Asphalt to Aging

Abstract

The knowledge of the factors affecting the susceptibility of asphalt to aging can be of help when selecting the asphalt binders for the construction of durable pavements. Investigated were the aging-induced changes in the chemical composition and colloidal nature of asphalts differing in origin and technology. It was shown that the course of the changes in the generic composition of asphalt upon aging under laboratory conditions depends on the chemical type of the feedstock from which the asphalt has been derived. During aging of the asphalts from the paraffin–naphthenic crudes, the resins undergo partial decomposition, which results in the increase of the cyclic fraction content. Although the increase of the asphaltene content in air-blown asphalts after the Thin Film Oven Test was found to be lower than that in the corresponding straight-run asphalts, the much higher value of the instability index and smaller size distribution of asphaltenes in the air-blown asphalts permit us to expect that their utilization as binders in pavement construction will lead to the reduction of pavement durability. It follows from the results of this study that not only the generic composition but also the structure of the fractions affect the resistance of asphalt to aging.     

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 ANSHAN PAVING ASPHALT

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.     

道路石油沥青中蜡对沥青性质的影响

测定了大庆和辽河１００号道路石油沥青中蜡的分布,并将其中的饱和蜡,芳香蜡,总蜡分离出来,用其与脱蜡沥青调制成蜡含量不同的系列样品,考察了饱和蜡,芳香蜡对沥青物理性质的影响,总蜡对沥青路用性能的影响,对沥青质量指标中否应设置蜡含量指标进行了讨论．     

THE STUDY OF PRODUCING HEAVY TRAFFIC ASPHALT BY USING THE HIGH VISCOUS CRUDE FROM NO.l SHUGUANG ZONE OF LIAOHE OIL FIELD

The characteristics of the high viscous crude from No. 1 Shuguang Zone of Liaohe Oil Field are similar to those of residue distillates of general crude such as high density(ρ ₂₀=0·9977 g.cm^-3),high viscidity υ ₁₀₀= 1223·9 mm².s-¹) and high carbon/hydrogen ratio. This oil contains less wax, but rich in resin and asphalt, which belongs to low sulfur naphthene-base crude oil and can be used as feedstock to produce high paving asphalt. But now it is used as fuel after emulsificating. In order to make full use of this oil and resolve the problem of paving asphalt demand-supply, various paving asphalts conforming to GB50092-96 standard were produced by blending vacuum residue of the high viscous crude from No.l Shuguang Zone of Liaohe Oil Field and waste oil which is rich in aromatics and poor in wax. The laboratory test results show that modified paving asphalts have good low-temperature properties and antiaging feature.     

THE INFLUENCE OF METAL-CONTAINING COMPOUNDS ON ENHANCEMENT AND INHIBITION OF ASPHALT OXIDATION

ABSTRACT

Addition of lime to paving asphalts is known to inhibit oxidative aging of pavements. The mechanism of the action of lime in retarding oxidation is not known. In this work, an asphalt was mixed with a vanadium chelate that is known to strongly promote oxidation in asphalts. This enhancement of oxidation was largely neutralized when the mixtures were combined with hydrated lime. It is possible that lime acts by suppressing the catalytic activity of naturally occurring vanadium compounds that occur in almost all asphalts, although other mechanisms for the action of lime are also possible. The use of vanadium compounds in asphalt aging tests also is discussed.     

Study and Evaluation of Aging Performance of Petroleum Asphalts and Their Constituents During Oxygen Absorption. II. Chemical Group Composition and Structure Changes

Abstract

The changes of the chemical group compositions and the structures of Chinese Shanjiasi, Shengli, and Renqiu petroleum asphalts and their constituents during oxygen absorption were successfully studied based on the sample oxygen absorption behaviors. The research results show that every asphalt constituent after absorbing oxygen would change into the near heavier one with the exception of saturates, of which the greatest is the conversion rate of resin into asphaltene. The oxygen molecules absorbed by samples are mainly converted into the oxygen atoms in some oxygen-containing function groups, such as O-H, C=O, and S=O groups. The asphalt colloidal stabilities deteriorate clearly and the molecular weight distributions of asphalts and their constituents spread toward higher molecular weights. The molecular weights of all samples increase gradually after oxygen absorption. Resins and asphaltenes are the more unstable constituents in asphalts as shown by their evident changes after oxygen absorption. The changes of Shengli asphalt and its constituents absorbing more easily oxygen are clearly greater than those of Shanjiasi asphalt and its constituents.     

A STUDY OF RHEOLOGICAL PROPERTIES OF LIME TREATED PAVING ASPHALTS AGED AT 60°C IN A PRESSURE AGING VESSEL

Abstract

The oxidation and age-hardening propensities of eight widely varying petroleum asphalts used for paving were studied with and without hydrated lime, and with inert particulate matter in place of lime. The results show that oxidation of sulfides to sulfoxides and benzyl carbon to ketone is affected very little by the presence of lime. However, the addition of lime does inhibit age-hardening in asphalt whereas the inert particulate matter in the same amount and particle size has little effect other than the filler effect exhibited by the lime and the inert particulate.

The principal inhibition of age-hardening of asphalt by hydrated time occurs at high pavement temperatures (> 60°C). At low and moderate temperatures (<50°C), age-hardening is very slow and typically not a major problem in pavement.

It is speculated elsewhere in detailed aging studies that the high temperature age-hardening of paving asphalts results from formation of multimolecular, three dimensional matrices in asphalt formed among polar molecules. Hydrated lime appears to interfere with this type of matrix formation, probably by chemical reaction with carboxylic and other acids, to reduce the sizes and/or strengths of the matrices. As a practical result, lime reduces the rate of hardening of asphalt hence prolonging the expected lifetime of a roadway.     

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.     

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.