建筑外墙腻子动态抗开裂性的表征方法

Characterization Method of Dynamic Cracking Resistance of Putty for Exterior Building Walls

通过对批刮2 mm厚腻子的预制裂纹无石棉纤维水泥平板施加应力,模拟墙面微裂纹的动态发展过程中腻子膜对基层微裂纹的覆盖能力,根据应力-应变曲线中峰值点对应的最大载荷、行程、位移和曲线面积来表征腻子膜的动态抗开裂性。结果表明:各类型建筑外墙腻子在峰值点对应的最大载荷、行程、位移具有明显的区分度,应力-应变曲线面积也具有明显差异,可实现对腻子膜柔韧性较为精确的定量评价,弥补了现行标准中动态抗开裂方法测定腻子膜柔韧性的不足。该方法有望对标准的修订有一定的参考作用。

In this paper,by applying stress to the pre-cracked non-asbestos fiber cement slabs with 2 mm thick putty,the ability of the putty film to cover micro-cracks in the base layer during the dynamic development of wall micro-cracks is simulated.The dynamic cracking resistance of the putty film was characterized according to the maximum load,stroke and displacement corresponding to the peak,and the curve area of the stress-strain curve.The results showed that the maximum load,stroke and displacement corresponding to the peak of various building exterior wall putty had obvious discrimination,and the area of stress-strain curve was also significantly different,and a more accurate quantitative evaluation of the putty film flexibility could be achieved,which made up the deficiency of the dynamic anti-cracking method in the current standard.It was hopeful to provide a reference for future revisions of the standard.