摘要
为寻求一种更好的粘结介质以改善CFRP筋粘结式锚具的锚固性能,通过静载试验研究了不同表面形状和锚固长度的CFRP筋在超高性能混凝土RPC、环氧铁砂、环氧石英砂和普通混凝土等四种不同粘结介质中的受力锚固特征。结果表明:CFRP筋的表面形状显著影响其锚固性能;CFRP筋在环氧铁砂和环氧石英砂中的锚固性能基本一致;在其他条件相同时,RPC对CFRP筋的锚固性能最好,环氧砂次之,普通混凝土较差;对于抗拉强度保证值2550MPa、直径10mm的表面压纹CFRP筋,其在抗压强度为130MPa的RPC中的锚固长度达到25d(d为CFRP筋的直径)时即可保证CFRP筋的强度予以充分发挥,而同样的CFRP筋在环氧砂和普通混凝土中的锚固长度为35d时亦不能保证CFRP筋被拉断。因此,在目前可供选择的粘结介质中,RPC作为综合性能优良的粘结介质可在粘结式锚具中对具有表面压纹的高强CFRP筋提供最有效的锚固。
In order to find a better bond medium to improve the performance of bond-type anchorage systems for CFRP （Carbon Fiber Reinforced Polymer/Plastics） tendons, pull-out tests on the behavior of bond-type anchorage for CFRP tendons were conducted. The test parameters in all 30 specimens include 2 different tendon surface shapes, plain or indented, 4 different bond mediums of ultra high performance concrete RPC （Reactive Powder Concrete）, epoxy steel ball, epoxy silica sand and normal concrete and different grouted length of tendons from 15d to 45d （d refers to the diameter of CFRP tendon）. Test results indicate that the surface shape of CFRP tendon has significant effect on tendon＇s anchorage behavior in all 4 bond-mediums. The influence of different aggregates with steel ball and silica sand in epoxy to the bond behavior of the epoxy medium could be neglected. Further, the anchorage performance of CFRP tendon in RPC is the best and in normal concrete the worst. As for the intended surface of CFRP tendon with a 2550 MPa guaranteed tensile strength and a 10 mm diameter, the grouted length of 25d in the RPC of a compressive strength 130 MPa can thoroughly bring out CFRP tendon＇s tensile strength. However, a grouted length of 35d in epoxy sand and normal concrete still could not assure the same tendon to be ruptured. In the case of different bond media, RPC shows the best performance as a bond medium in the bond-type anchorage for the indented surface CFRP tendons.
出处
《土木工程学报》
EI
CSCD
北大核心
2006年第6期47-51,共5页
China Civil Engineering Journal
基金
国家自然科学基金(50478052)
教育部优秀青年教师资助计划项目
