沥青混合料集料接触特性切片图像评价方法

Aggregates Contact Characteristics Evaluation of Asphalt Mixtures by Analyzing Cut Images

为了评价沥青混合料集料的接触特性,提出了一种较能准确有效评价沥青混合料集料接触特性的新方法。研究中建立了表征集料接触特性的量化指标——接触对,以AC20型沥青混合料为例,对车辙板试件的72幅切片图像进行了分析,通过对所有切片的集料接触数据进行统计分析,得到了集料接触对数目的分布规律。在此基础上,还进行了集料接触特性的影响因素分析,并提出了影响集料接触特性的3个主要因子:4.75 mm以上集料含量C>4.75、细度指数FI和离析指数SI。结果表明这3个因子与集料接触对之间有较好的关联度,集料接触特性变化受3个因子共同作用的影响,单因素或双因素都不能正确反映样本的接触对数目。

In order to evaluate the aggregates contact characteristics of asphalt mixtures, an effective method of evaluating the aggregates contact characteristics of asphalt mixtures was proposed. The ＂contact couple＂ was established as a quantitative index of aggregates contact characteristics and 72 digital images of mixtures＇ cut sections were obtained from the rutting test samples of AC20 HMA. Thus a statistical analysis of contact couples was made from the digital images. It is indicated that the contact couples are with normal distribution. Besides, the scale ratio of aggregates above 4.75mm （C〉4 75）,the fine index （FI） and the segregation index（S/） were presented as main impact factors of aggregates contact characteristics. And further investigation of the relationship between impact factors and aggregates＇ contact characteristics was carried out. It is revealed that the impact factors have good correlation with the contact couples, the interaction of impact factors is the main reason that influenced the aggregates contact characteristics, neither single factor nor dual factors can reflect the samples＇ contact numbers exactly.