混凝土T梁非均匀收缩效应研究  

Study on Non-uniform Shrinkage Effect of Concrete T-Beam

作　　者：刘敏 曾斌[2] LIU Min;ZENG Bin(Yunnan Highway Engineering Supervision and Consultancy Co.,Ltd.,Kunming,Yunan 650021,China;Chang′an University,Xi′an,Shaanxi 710000,China)

机构地区：[1]云南省公路工程监理咨询有限公司,云南昆明650021 [2]长安大学,陕西西安710000

出　　处：《山西交通科技》2023年第2期60-63,68,共5页Shanxi Science & Technology of Transportation

摘　　要：混凝土T梁在使用过程中腹板竖向裂缝的出现将对混凝土桥梁的耐久性和结构的承载能力造成严重的威胁。为了解决这一问题,研究了尺寸效应和钢筋约束对收缩应变情况的影响;根据平截面假定,推导了T梁截面非均匀收缩导致的收缩应力及自平衡应力随时间变化的计算方法;算例分析结果表明,普通钢筋对混凝土收缩变形的约束作用加剧了T梁截面的不均匀收缩效应,T梁截面的不均匀收缩效应十分显著,这一效应在T梁腹板处引起了较大的拉应力。The vertical cracks of the web of the concrete T-beam during use will seriously threaten the durability of the concrete bridge and the structure′s bearing capacity.To solve the problem,this paper studied the influences of the size effect and the reinforcement restraint on the shrinkage strain.According to the plane-cross section assumption,a method to calculate the change of shrinkage stress and self-balancing stress of the T-beam section caused by the non-uniform shrinkage with time was derived.The analysis of examples showed that the restraint effect of normal reinforcement on the shrinkage deformation of concrete enhanced the non-uniform shrinkage effect of the T-beam section,which was significant and caused a large tensile stress at the web of the T-beam.

关 键 词：混凝土T梁 尺寸效应 非均匀收缩 自平衡应力 腹板开裂 

分 类 号：U448.212[建筑科学—桥梁与隧道工程]