钢筋混凝土柱在长期荷载下的配筋率研究

钢筋混凝土柱在长期荷载作用下,考虑卸载影响时,柱中混凝土将会产生拉应力,配筋的多少将会直接影响到拉应力的大小,从而影响结构的安全。通过简化的分析方法推导了卸载前后柱中钢筋应力与混凝土应力的计算公式,并且在应力分析中,考虑了混凝土的徐变及弹性模量的时效性。同时,结合具体的各种相关参数,分析了柱高和配筋率对柱中最大混凝土平均应力的影响。最后,提出了最大配筋率的计算方法。

STUDY ON REINFORCEMENT RATIO IN REINFORCED CONCRETE COLUMN UNDER LONG-TERM LOAD

Unloading results tension stress in concrete column under long term load.The amount of the reinforcing bars,however,influences the tension stress and the serviceability of the member.The formula for calculating the stress in concrete and reinforcement before and after unloading is presented through some simplifications.During the analysis of them,the time dependent conrete properties,creep and the change of modulus are taken into account.At the same time,combined with some concrete correlation parameters,the influence of the length and reinforcement ratio of column on the maximum average stress in concrete is researched.At last,the formula for calculating the maximum reinforcement ratio is proposed.