新老混凝土粘结面人造粗糙度表征及性能研究

Characterization and Properties of Artificial Roughness of Young on Old Concrete Bonding Interface

提出了一种改进的老混凝土表面人造粗糙度处理方法,并进行了试验研究.首先采用数字图像法采集粗糙表面的三维轮廓数据,然后依据分形理论进行数据处理,并用分形维数表征人造粗糙度;再利用自编的MATLAB程序实现粗糙表面的三维重建以验证数字图像法的准确性;最后,研究了老混凝土表面粗糙度与新老混凝土粘结性能的相关性,结果显示,人造粗糙表面是一种分形结构,可采用分形维数表征其粗糙度;新老混凝土粘结抗折强度f与老混凝土表面的分形维数D呈正相关性,存在近似关系f=kD+b,其中k,b为拟合系数;数字图像法在试验的数据采集、处理分析以及界面形貌的三维重建阶段都具实用性.

An approach to form a better artificial roughness of old concrete surface was proposed, and an experimental study was carried out. First, the three-dimensional contour data of the rough surface of old concrete were collected by digital image method, then the data were processed based on fractal theory, and fractal dimension was used to characterize the artificial roughness. Then three-dimensional reorganization of the rough interface was achieved by MATLAB program, so that the accuracy of the digital image method was verified~ Finally, the correlation of the roughness and the bonding properties of young on old concrete was investigated. The results show that the artificial roughness is a fractal structure, which can be characterized by fractal dimension. There was a positive correlation of fractal dimension （D） and interfacial bonding properties （f）, which can approximately be formulated as f = kD q- b ; Digital image method is useful in data acquisition, processing, analysis, as well as the three- dimensional reconstruction of interface morphology.