Study of Post-Installed Anchors in Low Strength Concrete

• Main Authors: Hsiao-Ying Li 李曉盈, 李曉盈
• Other Authors: Shyh-Jiann Hwang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/96650594547862814112

碩士 === 國立臺灣大學 === 土木工程學研究所 === 101 === In order to increase seismic capability of structural system, retrofit techniques are usually applied. Traditional RC retrofit methods include adding RC shear wall, wing wall and RC jacketing. In addition to connect new structural members to old structural members anchor bolts (bar implant) are used. From the investigation results by NCREE, we can find that concrete strength of old school buildings is pretty low due to poor structural system and quality. Therefore, the behavior of post-installed anchors in low strength concrete is very important. Anchor system can be categorized into two kinds. Cast-in anchor is installed before placing concrete and post-installed anchor is installed in hardened concrete. Therefore, post-installed anchor is suitable in retrofitting structures. 　　Low strength concrete specimens were designed for rebar-implanting. Through pulling out embedded steel bars from hardened concrete, the failure modes of embedded steel bars are investigated. The influence of the depth of steel bars, concrete strength and detail of specimens is analyzed. Test results indicate that Hilti’s suggestion embedment should be carefully used in accordance with it allowable tensile forces. In addition, NCREE’s suggestion embedment is too conservative we can reduce its length to 65%.