钢纤维自应力混凝土加固简支变连续梁疲劳试验

Fatigue tests of simple-support beams strengthened to continuous beams with SFRSC

以钢纤维自应力混凝土(SFRSC)作为加固材料,研究有损伤的简支梁加固为连续梁后的疲劳性能.分别采用SFRSC、钢纤维混凝土和普通混凝土作为湿接缝接头和叠合层材料,对有损伤的简支梁进行加固.通过疲劳试验,对负弯矩区及跨中钢筋的应力水平、裂缝宽度及跨中挠度等进行了对比分析.试验结果表明,SFRSC加固简支梁变连续梁,可有效降低负弯矩区及跨中钢筋应力幅、裂缝宽度和跨中挠度,提高结构的疲劳寿命和正常使用性能.与普通混凝土加固梁相比,10万次疲劳循环后,SFRSC加固梁负弯矩区的最大裂缝宽度降低25.0%～32.0%.

Steel fiber reinforced self-stressing concrete（SFRSC）was used as strengthening material,and fatigue properties of damaged simple-support beams strengthened to continuous beams were studied.SFRSC,steel fiber concrete and ordinary concrete were used as wet joints and composite layer materials to strengthen simple-support beams respectively.Through fatigue tests,stress levels of reinforcements in hogging moment area and mid-span,crack widths and mid-span deflection were comparatively analyzed.The experimental results show that SFRSC strengthening simple-support beams to continuous beams can reduce stress amplitude of reinforcements in hogging moment area and mid-span,crack widths and mid-span deflection,and can improve structure fatigue life and normal use performance.Compared with beams strengthened by ordinary concrete,the maximum crack width in hogging moment area of beams strengthened by SFRSC can be decreased 25.0%-32.0% after 100 thousand fatigue cycles.