超高性能纤维增强混凝土管的三边承载实验研究

Mechanical properties of UHPFRC pipes using three edge bearing method

配制了超高性能纤维增强混凝土(UHPFRC),采用三边承载实验研究UHPFRC管(配筋和不配筋)的承载能力、变形能力、应变和裂纹分布等。结果表明,钢筋增强UHPFRC管的承载能力和管顶挠度分别为无筋UHPFRC管的2.5倍和3.5倍。钢筋增强UHPFRC管的变形率为6.5%,埋地后能呈现非刚性混凝土管的特征。强度等级和内径相同时,钢筋增强UHPFRC管的管壁厚度明显低于普通钢筋混凝土管,是一种薄壁管。在达到破坏荷载时,钢筋增强UHPFRC管的拉、压应变均高于无筋UHPFRC管。钢筋增强UHPFRC管呈现多裂纹开裂特征,裂纹的宽度随荷载增加而增加。

The Ultra High Performance Fiber Reinforced Concrete （UHPFRC） was prepared and the bearing capacity, deformation capacity, strain and crack distribution of UHPFRC pipe （reinforcement and not reinforced） were studied by the there-side bearing test. The results show that the load-carrying capacity and the deflection of the top of the steel reinforced pipe are 2.5 times and 3.5 times higher than that of the unreinforced UHPFRC pipe. The deformation rate of steel reinforced UHPFRC pipe is 6.5%,which shows the characteristics of the non rigid concrete pipe after being buried. The concrete wall with the same strength grade and inner diameter, when the steel reinforced UHPFRC pipe is adopted,the pipe wall thickness is obviously lower than the ordinary reinforced concrete pipe. It is a thin-walled tube. When the failure load is reached,the tensile and compressive strains of the reinforced UHPFRC pipe are higher than unreinforeed UHPFRC pipe. The steel reinforced UHPFRC pipe exhibits multi crack characteristics,and the crack width increases with the increase of load.