混凝土干燥收缩开裂评价及其试验新方法

A New Evaluation and Test Method for Shrinkage-Crack of Concrete

介绍了一种评价混凝土收缩开裂的试验和评价方法,该法能够准确测量约束状态下混凝土干燥收缩时其内部产生的拉应力,特别是能够客观评价补偿收缩混凝土在弹性限制条件下抵御收缩应力的能力;提出了干燥收缩开裂概率C的概念,并将混凝土发生干燥收缩开裂的概率划分为C≥60%(高开裂风险),40%≤C<60%(中等风险)和C<40%(低风险)三种状态;试验表明,补偿收缩混凝土能够在混凝土中建立一定的自应力,可以有效降低混凝土的干燥收缩开裂概率。

This paper has introduced a new method on the evaluation and test for concrete shrinkage and crack. This method could measure the accurate internal tensile stress brought by dry shrinkage of concrete. A concept of dry shrinkage crack probability (C) has been put forward by which the concrete dry shrinkage crack probability could be devided into three levels named as: C≥60%(high risk),40%≤C<60%(medium risk)and C<40%(low risk). Tests have showed that the self-stress produced inside the shrinkage compensating concrete could reduced the concrete dry shrinkage crack probability effectively.