Research on the Causes of Appearance Quality Defects and Control Countermeasures for Precast Girder
In order to improve the appearance quality of the precast box girder,the appearance quality defects of prefabricated box girder with clear mirror concrete were classified,the differences of hydra-tion products were observed by scanning electron microscopy(SEM)and X-ray diffraction(XRD)and other microscopic test methods,the formation mechanism of various defects was analyzed,and im-provement measures to effectively control the appearance quality defects of concrete were proposed from the aspects of cement hydration products and pouring process,etc.The results show that the differences of hydration products,concrete gas content and working performance are the main causes of various appearance quality defects of precast box girder.The digital and intelligent concrete raw materials and construction technology control measures are put forward to reduce the number of pre-cast box girder with unqualified appearance quality by 72.7％,and increase the number of precast box girder with excellent and good appearance quality by 62.5％,effectively improving the appearance quality of precast box girder and achieving the goal of high quality project construction.
万方数据
维普
