利用波形齿锚具实现横向张拉CFRP片材的体外预应力加固技术,对4根完全相同的7 m跨度的T型梁进行加固(梁侧加固3根梁,其中1根梁考虑二次受力影响;梁底加固1根梁);利用普通粘贴CFRP的加固技术对另一根梁进行加固(加固前与前4根梁完全相同);然后对加固后的5根梁进行试验研究。结果表明:梁侧或梁底CFRP片材体外预应力加固能同时显著提高混凝土梁的开裂荷载、屈服荷载、极限承载力以及截面刚度,能有效限制混凝土裂缝宽度的发展,也能充分发挥CFRP片材高强性能,同时加固时有无初始荷载即二次受力对加固后的梁在承载力及变形能力方面均无明显影响。
Abstract
The external prestressed strengthening technique is that carbon fiber reinforced polymer (CFRP) sheet is not affixed to the beam and lateral is pulled by wave-shaped-gear (WSG) anchor and grip at two sides or bottom of the beam. Four same 7 m long reinforced concrete T-beams were designed to test. Three beams were strengthened at two sides of the beam by above strengthening technique. One beam is strengthened at bottom of the beam by above strengthening technique. But another beam was strengthened by sticky CFRP strengthening technique. Test results indicate that this external prestressed CFRP sheets strengthening at two sides or bottom of beam can significantly improve the cracking load, yield load, ultimate bearing capacity, and sectional stiffness of RC beams. The width of flexural crack in concrete beam is effectively controlled and the high strength capacity of the CFRP sheet is exploited. At the same time, secondary load has no obvious influence on the bearing capacity and deformability of strengthened beam.
关键词
桥梁工程 /
钢筋混凝土T型梁 /
试验研究 /
波形齿锚具 /
预应力 /
CFRP片材
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Key words
bridge engineering /
reinforced concrete T-beam /
experimental research /
wave-shaped-gear anchor /
prestress /
CFRP sheet
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中图分类号：
U445.72
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脚注
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基金
重庆市自然科学基金项目(CSTC2008BB6181);重庆大学研究生科技创新基金项目(200603Y1B0100153)
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