Abstract: The whole process of asphalt creation，from foaming to de-foaming and maintaining a stable state，is introduced from a micro view and its foaming mechanism is analyzed.The conclusion is drawn that the foaming process of asphalt is the interaction between asphalt film surface tension and interior vapor pressure.The disadvantages of applying existing evaluation indexes to foamed asphalt warm mixing technique were analyzed from three aspects of theory，testing，and application to foamed asphalt warm mixing technique of the existing evaluation indexes of foamed asphalt.Finally，three new evaluation indexes，these being foam diameter，size distribution，and de-foaming rate，were proposed based on use of a laser range finder and digital camera，among other equipment using a non-contact testing method.The results of the study show that the non-contact testing method combined with the new indexes can better evaluate the effect of asphalt formation.

Key words: highway engineering, foamed asphalt, foaming mechanism, expansion rate, half-life, evaluation indexes

摘要： 从微观上介绍沥青从发泡到消泡、维持稳定状态的整个过程并分析其发泡机理，得出沥青发泡过程是沥青膜表面张力与内部蒸汽压力相互 作用过程；再从现有泡沫沥青评价指标本身理论、试验、用在泡沫温拌技术3方面分析现有评价指标直接套用在泡沫沥青温拌技术上的不足；最后 提出基于激光测距仪、数码相机等设备的非接触试验方法以及泡沫直径、尺寸分布、消泡速率3个新评价指标。研究表明非接触试验方法与新指标 相结合能更好评价沥青发泡效果。

关键词: 道路工程, 泡沫沥青, 发泡机理, 膨胀率, 半衰期, 评价指标