Research On Duct Grouting Technology Of Prestressing Tendons

With the widespread application of prestressed concrete, civil engineers are concerned for the durability of the presressed concrete construction. The durability especially due to the quality of duct grouting has a significant influence on the safety and life period of the construction, so it must be deeply emphasized.This paper makes serial experimental research and analysis aiming to the prestressed concrete duct grouting technology. The contents are as follows:1. The test about the bleeding ratio of grouting material includes two methods: one is in lab using standard cylinder, another is on site with vertical duct. The results show that the testing with cylinder in the lab can not represent the true bleeding condition in the duct.2. The analysis for flowing condition of the grouting material in the duct. Considering the different waveform of the duct, the paper analyses the flowing condition with the change of the current velocity.3. The testing about natural flowing speed of the grouting material. According to different slope angle of the duct, the paper gets different data about natural flow speed. With all the results including the natural flow speed, the grouting speed and the analysis about flowing condition of grouting material, we can appreciate the true flowing behaviour of the grouting material, and consequently estimate the different influence on the ultimate quality of grouting with different flowing behaviour.Based on the test and analysis mentioned above, the paper mainly makes research on the grouting technology and analyses all kinds of grouting quality questions and phenomena with the angle of flowing behaviour. The phenomena and grouting quality flaw are confirmed in the test â… . In the test â…¡, some improved measures are brought forward. The test demonstrates that the improved measures can guarantee the grouting quality and they are operational and feasible on site. Simultaneously, the paper puts forward the flowing filling degree which judges the flowing behaviour of the grouting material in the duct. The paper also contains the...