中文摘要：

长期以来，如何评价准脆性材料的脆性一直是一重要问题。然而，现有的大多数脆性指标存在明显的局限性，即显著受试件尺度的影响，往往反映的是材料的脆性行为，而不是材料性质。基于Bazant尺寸效应律，强度与试件尺寸双对数曲线图中两条渐近线的交点或与之相关的有效断裂过程区长度可反映材料脆性。该脆性指标测定简单方便、真实可靠，能广泛应用于各种准脆性材料脆性评价。

英文摘要：

How to evaluate the brittleness of quasibrittle material has been a focus of attention in material science for years. However, there is a remarkable shortcoming for the most available brittleness indexes that they are influenced distinctly by size of testing sample. So they are not material property but material behavior. Based on size effect law proposed by Bazant, the intersection point of the asymptote of size effect curve and the fracture process zone length are suggested to reflect the brittleness of materials. The indexes can be used widely for quasibrittle material because it can be achieved easily and exactly.