预应力孔道灌浆密实性及防治泌水方法的试验研究

Experimental study on grouting compactness of prestressed duct and technology to deal with the grout bleeding

后张法预应力混凝土工程施工中,预应力孔道中泌水的存在,严重影响了预应力体系的耐久性。结合不同的灌浆工艺,对3种灌浆料进行了预应力孔道灌浆密实性试验。试验结果表明,各种灌浆材料都有泌水发生,都存在灌浆不密实的现象。真空灌浆工艺的灌浆效果优于普通灌浆工艺,但也不能完全解决灌浆不密实的问题。为此,结合具有自主知识产权的预应力孔道灌浆密实装置,对带垭口波纹管的灌浆密实性进行试验验证,其效果良好,能有效解决灌浆过程中的泌水问题,从而达到保证预应力筋与灌浆材料的黏结强度和防治预应力筋锈蚀的目的。

In the construction of post-tensioned prestressed concrete projects, the bleed water of grout in ducts seriously affects the durability of prestressed system. Combination with different grouting techniques, grouting compactness experiments of prestressed duct with kinds of grout materials produced by domestic manufacturers were carried out. The results show that there are bleed water in all kinds of grout materials and the ducts cannot be completely filled with grout. Grouting quality of vacuum-aided grouting technique is better than that of ordinary grouting technique, but it still cannot effectively solve the problem of grout bleeding. Based on the grout compacting device with independent intellectual property, the grouting compact- ness experiment of bellows with narrow pass was carried out, and the result proved successful. This kind of bellow can effectively deal with the grout bleeding, and reach the purpose of possessing well bond strength between grout and prestressed tendon and protecting the prestressed tendon from corrosion.