碱性物质对沥青热老化的影响

对两种沥青进行薄膜烘箱试验（ＴＦＯＴ）和掺加碱性物质的ＴＦＯＴ试验，用沥青蒸发损失率随ＴＦＯＴ时间的变化、沥青化学组成的变化和沥青红外光谱的变化阐述沥青热老化的原因，时比沥青抗老化性能的优劣，考察线性物质对沥青热老化的影响．结果发现：碱性物质使沥青蒸发损失率降低，可能是碱性物质促进沥青吸氧所致；碱性物质促进沥青中重胶质和沥青质的生成，使沥青在１７Ｏｃｍ－１附近的红外吸收强度明显增强，进一步说明碱性物质促进沥青吸氧．沥青ＴＦＯＴ后其重胶质和沥青质增加程度及其在１７０ｃｍ－１处的红外吸收强度变化程度能够表征其抗吸氧老化性能优劣，反映沥青胶体体系变化程度．     

沥青混合料抗老化性能的研究

本文针对二种国产重交通沥青及混合料,应用老化试验,来分析它们老化前后的力学性能差异,从而评价其抗老化性能。     

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。     

道路沥青吸氧老化性能的研究(二)与户外自然老化的关系

本文考察了膜厚为3.2mm的任丘、大庆、单家寺和弧岛4种道路沥青4年户外自然老化的规律,并以此判断沥青耐久性的优劣。用它们的延度变化曲线可以很好地解释这些沥青所辅设试验路面的使用性能。膜厚为3.2mm 和800μm 的沥青,其100h 吸氧试验的老化情况分别相当于3个月和12个月的自然老化吸氧试验,和自然老化的结果有较好的相关性。沥青在使用过程中的老化主要由氧和沥青的化学反应性所决定,即沥青的耐久性由它们的组成所决定.     

沥青光氧老化研究进展

介绍了沥青的光氧老化机理，着重评述了现有的沥青及沥青混合料的光氧老化试验和老化后性能表征方法，阐述了改善沥青耐老化性能的途径。通过研究沥青光氧老化评价的方法，探索提高沥青抗光氧老化能力的途径具有重要的现实意义。     

反相气液色谱法快速评价沥青的抗老化性能

采用反相气液色谱技术,用甲苯将沥青溶解后均匀涂渍在担体上,作为固定相,在实验条件下,测定分析物质(苯酚)在各种沥青柱上的相对保留时间随吸氧老化时间的变化,分别用差值法、全面积法和老化特性指数法快速评价了四种具有代表性的国产石油沥青的抗老化性能,并对各种评价方法进行了讨论。结果表明,本方法具有操作简便、直观、样品用量少、评价速度快、灵敏度高、重复现性好等优点,是一种快速有效地评价沥青抗老化性能的方法。     

两种沥青老化后的流变性能分析

为了研究基质沥青与改性沥青老化性质的差异,通过薄膜烘箱试验以及压力老化试验分别模拟沥青不同时间的短期老化和长期老化,然后通过DSR试验得到原样沥青以及不同老化程度沥青的流变数据,分析基质沥青与改性沥青的老化性质和沥青的低温玻璃化转变情况、模量大小、黏弹性组成等方面的信息,以及在工程使用中的实际意义。     

反相气液色谱法研究沥青的吸氧老化性能

本文采用反相气液色谱(IGLC)技术研究欢喜岭氧化沥青、欢三联直馏沥青、大庆调合沥青及西班牙沥青的吸氧老化性能。结果表明:沥青吸氧老化后相对极性增加,相对保留时间(RRT)增加,其中含氧分析物质的相对保留时间变化比含硫、氧及芳烃分析物质的更为明显。     

石油沥青及其组分吸氧老化中化学组成和结构的变化

考察了单家寺和胜利直馏100号道路石油沥青及其组分在吸氧老化中化学族组成和平均结构参数的变化,结果表明,沥青的各组分变重,平均分子量增大;各种试样平均分子中的总碳数、总环数、缩合指数和芳香度增加;胶质和沥青质组分变化最明显,是沥青中最不稳定的组分;沥青吸氧确为缩合反应。两种沥青相比,吸氧量较多的胜利沥青及其组分的变化明显高于单家寺沥青及相应组分的变化。     

道路沥青在使用过程中的水老化

在沥青的压力老化试验（PAV）中，设计加入水分因子，并采用美国战略性公路研究计划（SHRP）中的高温车辙因子（G^＊／sinδ）和低温蠕变劲度（S（t））等参数指标，表征在沥青路面使用过程中，雨水、地下水等潮湿因素对沥青老化性状的影响。结果表明，在热、氧的共同作用下，水分的存在对沥青G^＊／sinδ的影响十分显著。提出了在室内沥青长期老化模拟试验过程中，应考虑加入水分条件，使更接近致使道路沥青老化的使用环境，提高对沥青老化模拟的准确度。另外，从对沥青SHRP高温性能指标的影响程度上讲，水分因子的加入可以缩短沥青压力老化试验时间5h以上。     

反相气液色谱法研究沥青的吸氧老化性能

采用反相气液色谱技术,用甲苯将沥青溶解后均匀涂渍在担体上,作为固定相,在色谱吸氧老化条件下研究了沥青的吸氧老化性能。结果表明,沥青吸氧后相对极性增加,与沥青极性基团相似的分析物质的保留系数增加。氧化中各种沥青的老化综合指标存在较大的差别,可用来评价沥青的抗老化性能。     

Study and Evaluation of Aging Performance of Petroleum Asphalts and Their Constituents During Oxygen Absorption. I. Oxygen Absorption Behaviors and Kinetics

The oxygen absorption behaviors and kinetics of Shanjiasi, Shengli, and Renqiu petroleum asphalts and their constituents including saturates, aromatics, resins, and asphaltenes were successfully studied at 50°C, 0.133 MPa (O₂) and 1 mm sample film in darkness by means of precise measurement of oxygen pressure changes in reactor. The experimental results that the resin and the asphaltene can easily absorb oxygen and they are more active constituents in petroleum asphalt, while the saturate hardly absorbs oxygen, which is the most stable constituent of petroleum asphalt. The better the antiaging performance of straight run petroleum asphalt, the more stable its constituents and the less oxygen they absorb generally. The oxygen absorption rate of asphaltene diluted with the lower viscous saturate is obviously higher than that of pure asphaltene. The resin constituent of Shanjiasi asphalt could remarkably improve the antiaging ability of Shengli asphalt by the constituent substitution. The kinetic model of maximum combined oxygen presented in this paper could satisfactorily explain the oxygen absorption behaviors of petroleum asphalts and their constituents, and the oxygen absorption quantities calculated by the model are very identified with the test ones.     

Study and Evaluation of Aging Performance of Petroleum Asphalts and Their Constituents During Oxygen Absorption. I. Oxygen Absorption Behaviors and Kinetics

Abstract

The oxygen absorption behaviors and kinetics of Shanjiasi, Shengli, and Renqiu petroleum asphalts and their constituents including saturates, aromatics, resins, and asphaltenes were successfully studied at 50°C, 0.133 MPa (O₂) and 1 mm sample film in darkness by means of precise measurement of oxygen pressure changes in reactor. The experimental results that the resin and the asphaltene can easily absorb oxygen and they are more active constituents in petroleum asphalt, while the saturate hardly absorbs oxygen, which is the most stable constituent of petroleum asphalt. The better the antiaging performance of straight run petroleum asphalt, the more stable its constituents and the less oxygen they absorb generally. The oxygen absorption rate of asphaltene diluted with the lower viscous saturate is obviously higher than that of pure asphaltene. The resin constituent of Shanjiasi asphalt could remarkably improve the antiaging ability of Shengli asphalt by the constituent substitution. The kinetic model of maximum combined oxygen presented in this paper could satisfactorily explain the oxygen absorption behaviors of petroleum asphalts and their constituents, and the oxygen absorption quantities calculated by the model are very identified with the test ones.     

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

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.     

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.     

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.     

沥青的老化与表征方法研究

通过分析沥青的老化机理,分析了影响基质沥青和改性沥青抗老化性能的因素,总结了目前研究沥青老化的方法以及评价沥青抗老化性能的方法。薄膜烘箱（TFOT）、旋转薄膜烘箱（RTFOT）以及压力老化容器试验（PAV）常用来模拟沥青的老化,并用沥青老化前后的宏观和微观结构的变化评价沥青的抗老化性能。     

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.     

Use of Fourier transform infrared spectroscopy to study ageing characteristics of asphalt binders

The present study aims at studying ageing characteristics of conventional bitumen, polymer modified bitumen (PMB) and warm mix asphalt (WMA) by using FTIR. Results of obtained FTIR spectrum were quantified by calculating different indices and finally based on these indices ageing index of the binders for short- and long-term ageing were calculated. Results showed ageing increased amount of complex and high molecular weight components of the binders. PMB was found to have greater ageing resistance than conventional asphalt binders. In case of WMA, results found to be inconclusive, requiring further investigation.     

INVESTIGATION AND EVALUATION OF PETROLEUM ASPHALT AGING PROPERTY ON OXYGEN ABSORPTION BY INVERSE GAS LIQUID CHROMATOGRAPHY

The aging mechanisms and performances on oxygen absorption of ten petroleum asphalts were studied and evaluated by the inverse gas liquid chromatography with the Aging Comprehensive Index, the Aging Subtraction Number, the Aging Total Area and the Aging Character Factor methods based on the changes of the retention coefficients of analytical compounds in the petroleum asphalt chromatographic column during continuous aging caused by oxygen absorption under an oxygen flow rate of 15∼30 ml/min at 140°C, after the inert support was evenly coated with toluene-dissolved petroleum asphalt and packed into the chromatographic column. The relative polarity of petroleum asphalt and the retention coefficients of analytical compounds increase after absorbing oxygen and the changes of the retention coefficients of the oxygen-containing analytical compounds, especially phenol are evidently greater than those of the nitrogen and sulfur-containing and aromatic analytical compounds. There are obvious differences between the retention coefficients of analytical compounds in the petroleum asphalt columns from different sources and between their changes with the aging on oxygen absorption. The repeated determinations of these evaluation methods show that the standard deviations are less than 1.63 and the variable coefficients under 0.2. The test data are found.to be reliable by Grubhs examination at 95% confidence level. Of the four evaluation methods the Aging Subtraction Number method is the most simple and convenient in operation and takes least time in evaluation.