Control of cracking due to drying shrinkage in reinforced concrete wall by reinforcing steels

钢筋混凝土构件的干缩开裂是一个难以控制的问题。通过减少混凝土干缩、增加配筋量以及在混凝土墙体中设置截面损失件人工诱导裂缝的控制缝，可以有效地控制混凝土墙体的裂缝。然而，由于目前尚无明确的裂缝评估方法，因此，对钢筋混凝土墙体裂缝控制的定量设计至今仍是不可能的。因此，为了估计干燥收缩开裂行为，（裂缝宽度、裂缝条数），提出了基于粘结分析的改进分析方法，并通过2006年的单轴约束收缩开裂试验和2007年的小比例模型试验验证了分析方法的有效性提出了基于粘结分析的裂缝宽度和裂缝数量的简单估算公式。根据这些公式，可以通过减少干缩、配筋和控制缝来定量控制混凝土墙体的裂缝。

It is not easy to control the cracking due to drying shrinkage in reinforced concrete(RC) member. Cracks occurring in RC wall can be controlled by a reduction of drying shrinkage, an increase of the reinforcing steel and the control joint that induces the cracking artificially by installing a section loss part in RC wall. However, because there is no definite method for the estimation of cracking, the quantitative design for crack control in RC wall is impassible as far. Accordingly, to estimate drying shrinkage cracking behavior(crack width, number of crack) in RC wall, an improved analytical method on the basis of the bond analysis was proposed, and the validity of the analysis method was confirmed from the uniaxial restrained shrinkage cracking test(2006) and the small-scale RC wall model test(2007).Simple estimation equations of the crack width and the number of crack based on the bond analysis were proposed. According to these equations, it is possible to control cracking quantitatively in RC wall by reduction of drying shrinkage, reinforcing steel and control joint.