混凝土结构的变形约束度及裂缝控制

混凝土的收缩变形和温度变形是其自然属性，而这种变形又是其结构或构件的非常重要和复杂的荷载。混凝土的温度变化和收缩必然要引起体积的变化．而混凝土变形受到约束时在混凝土中又必然产生应力，当混凝土中的拉应力等于或大干混凝土的抗拉强度时，混凝土就要产生裂缝。混凝土变形所受约束的程度可用约束度这一参数来度量，本文比较详细地介绍了约束、约束度、约束种类以及约束度与混凝土裂缝产生的内在联系，以期人们对约束度的认识和研究，防止和减小混凝土有害裂缝的产生。

Deformation constraint degree and cracking control for concrete structure

Concrete shrinkage deformation and temperature deformation are natural properties,and both of them are the key and complicated load in the concrete structure or component.Concrete temperature changing and shrinkage can cause the volume changing inevitably;the deformation caused by constraint in mixing process will give the stress,cracking occurred while the constrained stress is stronger than tensile strength.The constraint degree is a evaluation parameter.It expounds the constraint,constraint degree,constraint styles and the relation of constraint degree and cracking in detail,in order to improve our research and recognition and prevent and reduce the harmful cracking.