【摘要】 自密实混凝土由于材料组分和免振捣的特点,其与钢筋黏结性能备受关注。采用电液伺服加载方法分别进行了10个单调荷载作用和10个重复荷载作用下的钢筋混凝土试件拉拔试验,其中16个为自密实混凝土试件,4个为普通混凝土对比试件,研究自密实混凝土强度、荷载作用形式对钢筋与自密实混凝土局部黏结性能的影响,包括局部黏结应力的分布、残余黏结应力等。试验结果表明:沿锚固长度黏结应力分布在单调荷载作用下呈单波峰状,而在重复荷载作用下呈波浪状;自密实混凝土强度越高,黏结应力分布越不均匀,各级荷载卸载时的残余黏结应力也较大;随着循环荷载和次数的增加,黏结应力分布更均匀,残余黏结应力逐渐向自由端移动;自密实混凝土与钢筋的黏结性能略优于普通混凝土与钢筋的黏结性能。采用最小二乘法得到钢筋与自密实混凝土局部黏结应力分布的位置函数并与试验结果对比,表明其具有较好精度。更多还原

【Abstract】 The bond characteristics between self-compacting concrete and reinforcement are worth researching due to material constitution and no need of vibration.The local bond characteristics between self-compacting concrete and reinforcement were analyzed experimentally and test parameters included self-compacting concrete strength and loading pattern.The tests were conducted on ten specimens under monotonic loading and ten specimens under repeated loading,including sixteen self-compacting concrete specimens and four common concrete specimens.Reinforcement of all specimens was pulled out by electro hydraulic servo device.The local bond stress between self-compacting concrete and reinforcement was analyzed including bond stress uneven coefficient and residual bond stress distributions.The bond stress distribution curve shows wavy under repeated while single crest under monotonic load.The bond stress distribution is more uneven with concrete strength increasing but more even with cyclic loading and number of cycles increasing.When each level unloading,the residual bond stress is larger with concrete strength increasing and its distribution range transfers to free end with cyclic load and number increasing.The bond performance between self-compacting concrete and reinforcement is a little better than normal concrete.Based on the results,the regression equations for local bond stress position function under monotonic loading and repeated loading were obtained and were validated by test results.The regression equations agree with the test results.更多还原