道路沥青材料VOCs的指纹组分及其定量分析

深入开展沥青材料环境影响规律研究，是加快推进交通运输污染防治和绿色交通发展的重要手段之一。针对热拌沥青材料在使用过程中挥发性有机化合物（Volatile Organic Compounds，VOCs）释放量小、组分复杂且材料来源和环境因素依赖性强等难以定量表征的科学问题，开展包括不同沥青材料间VOCs公共组分、特有组分和超微量组分的VOCs全组分的特征研究。综合共计80种沥青材料的VOCs组分特征，提出并定义沥青材料VOCs的指纹组分。基于指纹组分的释放量-色谱峰面积的绘制，分别构建沥青材料VOCs中单一组分释放量和VOCs释放总量的计算方程。研究结果表明：不同沥青材料的VOCs释放差异显著，其组分信息和对应释放量均存在很强的原材料来源依赖性；沥青VOCs的指纹组分具有色谱峰面积大、组分纯、毒性强等特点，包括2-甲基戊烷、正己烷、3-甲基己烷、庚烷、2-甲基庚烷、丙酮、甲基丙烯醛、正丁醛、异戊醛、苯、甲苯和二硫化碳这12种物质；该系列指纹组分能够用于沥青材料VOCs的单一组分释放量和总释放量的快速准确分析；70A沥青、70B沥青、90A沥青、90B沥青和SBS改性沥青在160℃加热条件下的VOCs释放总量分别为4.42，3.32，2.52，2.29，1.88 μg·g^-1，其中指纹组分的总释放量分别为3.00，2.33，2.01，1.75，1.44 μg·g^-1；70号沥青中释放量最多的物质包括正己烷、2-甲基戊烷和庚烷，其释放量均大于0.40 μg·g^-1；90号沥青和SBS改性沥青中，释放最多的物质为正丁醛，其中90A沥青中正丁醛的释放量高达0.76 μg·g^-1。

Fingerprint Components and Quantitative Analysis of Volatile Organic Compounds of Asphalt Materials

The environmental impact of asphalt materials is one of the key issues for promoting green transportation and reducing air pollution. Quantitative analysis of the volatile organic compounds (VOCs) released from asphalt materials is quite challenging because of their relatively unnoticeable or small release quantity and complex compounds. This study focuses on the chemical characteristic analysis of asphalt VOCs. First, coexisting, independent, and ultramicro components in asphalt VOCs from five different asphalt materials were analyzed in detail. VOC information obtained from 80 types of asphalt materials was collected to establish a database of fingerprint components of asphalt VOCs. Second, the relationship between the released quantity and peak area from chromatograms in a mass spectrometer study was established for every fingerprint component. Research results indicate that the release characteristics of VOCs differ for each asphalt material. The chemical components and release quantity are highly variety-dependent. Different asphalt materials provide different VOC information. Fingerprint components of asphalt VOCs exhibit the highest peak area and degree matching of chromatograms and a high toxicity. These VOCs include 2-methylpentane, n-hexane, 3-methylhexane, heptane, 2-methylheptane, acetone, methacrolein, butyraldehyde, isovaleraldehyde, benzene, toluene, and carbon disulfide. Considering the relationship between release amount and peak area, the characteristics of fingerprint components can be used for the quantitative analysis of each VOC component and the total VOC release quantity from asphalt materials. The two types of pen 70 and two types of pen 90, and styrene-butadiene-styrene modified asphalt binders exhibit a total VOC release of 3.00, 2.33, 2.01, 1.75, and 1.44 μg·g^-1, respectively, when they are heated to 160℃. The chemical characteristics of asphalt VOCs indicate that n-hexane, 2-methylpentane, and heptane are the most released types of VOCs from the pen 70 asphalt binder, whereas butyraldehyde is the most released type of VOC from the pen 90 and SBS modified asphalt binders, where 0.76 μg·g^-1 of butyraldehyde is released from the pen 90 asphalt binder.