Abstract: In order to provide more convenient and accurate measurements of characteristics of concrete surface structure, based on the data of Shantou-Zhanjiang expressway in Guangdong province, rapid sampling by means of digital image processing technology and analysis and calculation in late stage was realized. And the influences of illumination, shooting angle and distance, image processing calculation rule and the cleanliness of concrete surface on the measurement results were also studied. The results show that filtering and denoising should be carried out before the surface structure characteristics of the concretes initial image are identified. When shooting angle is frontal, shooting distance has little effect on the gray value. With the increase of illumination，the gray value increases first and then decreases. Debris on the surface of concrete will be reflected on the image, thus interfering with the judgement of the characteristics of concrete surface structure. Therefore, the appropriate illumination should be selected through experiments, and maintain stability throughout the process. At the same time, the surface of the measured concrete should be kept clean.

Key words: highway engineering, concrete, surface structure, gray value, image method, illumination, exposed aggregate ratio

摘要： 为了更加方便准确地测量水泥混凝土表面构造特征，依托广东省汕头-湛江高速公路（简称汕湛高速），借助数字图像处理技术实现了现场快速取样、后期计算分析，研究了在测量过程中光照强度、拍摄角度和距离、图像处理计算法则及混凝土表面整洁度等因素对测量结果的影响。结果表明：对拍摄的初始图像进行混凝土表面构造特征识别之前应先进行滤波去噪处理；当拍摄角度为正面拍摄时，拍摄距离对灰度值测量结果影响较小；随着光照强度的增大灰度值整体呈现先增加后减小趋势；混凝土表面杂物会反映在所拍摄图像上，从而对混凝土表面构造特征的判断造成干扰，因此在测量过程中应通过试验选择合适的光照强度，并在整个测量过程中保持稳定，同时要保证被测混凝土表面整洁。

关键词: 道路工程, 混凝土, 表面构造, 灰度值, 图像法, 光照强度, 露骨率