采用内约束法评价轻集料混凝土的干燥收缩开裂

Measurement Method for Shrinkage and Crack of Light Aggregate Concrete

本文采用内约束收缩应力方法研究了轻集料混凝土表观密度、水灰比、轻集料品种、不同矿物掺合料对混凝土收缩开裂的影响。结果显示,轻集料混凝土表观密度的降低增大了干燥收缩开裂趋势,过低过高的水灰比对干燥收缩开裂均有不利影响,粉煤灰、磨细矿渣粉、硅灰的掺入降低了收缩开裂风险,混凝土收缩开裂概率随着限制程度提高明显增大。

In this paper, method of internal restrained shrinkage stress was adopted to research the influence on concrete shrinkage and crack from different aspects, including apparent density, water/cement ratio, type of light aggregate, and type of mineral admixture. The result shows that the decrease of apparent density of light aggregate concrete increases the risk of drying shrinkage and crack. Too low or low high water/cement ratio also has negative influence on drying shrinkage and crack. The addition of mineral admixtures such as fly ash, ground slag, silica fume, will reduce the risk of shrinkage and crack. The crack probability increases evidently with the restrained extent.