Naoto OGAWA
The Study on Bond Stress of Tendon
Takaya KAINO
The examination that pulls out tendon buried in the grout test piece is used to evaluate the bond characteristics of the fixed anchor grout and tendon that composes the ground anchorage. However, there is a doubt whether its result demonstrates under the ground or not. Then, I examined to pull out tendon by quasi-ground that was able to over burden arbitrarily , for the purpose of clarifying the bond characteristics of the anchorage which placed under the ground. In the examination, it pulled tendon out from the fixed anchor grout (length 100cm, diameter 9.0cm) which placed in the quasi-ground. The tendon was made the epoxy strand of PC steel strand caught with epoxy resin
The main result of obtaining in this study is shown as follows.
(1)Relative displacement : r of tendon and the fixed anchor grout was hardly generated while the early stage of s (the bond stress)|r curve, and r was greatly generated when the s reached a certain value. The s decreased rapidly after it had peaked.
(2)The maximum bond stress of two tendons has lowered more than one of a tendon about 30%.
(3)The maximum bond stress was considerably smaller than the pulling out examination result of using the rectangular grout test piece that placed the spiral hoop.
(4)The change in the maximum bond stress by the largeness and smallness of vertical pressure , it was hardly seen in this study.