The Performance Test Of The Duct Grouting And The Research Of The Construction Quality

The duct grouting was one of the most important factors for the post-tensioned concrete structures, the quality of the duct grouting directly affected the safety and the durability of structures during the using ages. At present the problem that duct grouting is not compacting is very serious in the bridge engineering. Some problems are researched to improve the quality of conventional grouting method by improving the grouting materials and the grouting technology based on the ChuHe great bridge at AnHui province.Taking into account the economical and utility factors, we selected some grouts with good performances by the contrasting test and the cross experiment.Four grouts were chosen based on their fluidity ,bleed resistance, expansion ratio and accelerated corrosion testing to proceed with large scale duct testing.Four groups large scale duct tests were completed. Each group test think over different content that were lognitudinal short duct test , lognitudinal long duct test ,vertical duct test and flat duct test. Unlike the before large scale duct tests completed by overseas research organizations, the tests were based on the true engineering, Some problems were took into account including laying the reinforcing steel bar , steel wind and hot-rolled threadbar etc.in ducts.The material tests indicate that the cement affects the grouting bleeding property, the cement/water ratio and water affect the grouting fluidity. At the same time the grouting bleeding and the cement/water ratio affect the accelerate corrosion time of the reinforcing steel bar.The position and the number of the vents were researched and the influence of grouting materials upon the quality of the flat duct grouting was discussed. At the same time the different grouting methods of vertical duct grouting were researched and the result indicated that the U duct grouting was good for the grouting quality.The phase fruit is valuable to improve the grouting quality of PC concrete structures .