Up to now, the compact compression specimens (CCS) have only been used to estimate the fracture toughness parameter of cement‐based materials. In the study, the linear elastic fracture mechanics formulae of CCS, namely, the universal weight functions with four terms, K_I (stress intensity factor), CMOD (crack mouth opening displacement), and COD (crack opening displacement) profile were, therefore, derived using the finite element method. To investigate the extent to which CCS tests could model the non‐linear fracture behaviour of concrete, 11 series of tests in the literature were subsequently examined for the effective crack models: the two‐parameter model, the size effect model, and the double‐K model. Two prediction formulae based on previous test data were proposed to estimate unstable fracture toughness and initiation fracture toughness of concrete. The results of CCS test‐based non‐linear fracture mechanics look viable and very promising.

中文翻译：

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利用紧凑压缩试样确定混凝土的非线性断裂参数

到目前为止，紧凑压缩试样（CCS）仅用于估计水泥基材料的断裂韧性参数。在研究中，CCS的线性弹性断裂力学公式，即具有四个项的通用权重函数，K _I（应力强度因子），CMOD（裂缝口张开位移）和COD因此，（裂纹开口位移）轮廓是使用有限元方法得出的。为了研究CCS测试可以模拟混凝土非线性断裂行为的程度，随后对文献中的11个系列的测试进行了有效的裂纹模型检查：两参数模型，尺寸效应模型和双参数模型。 K型。提出了基于以前的试验数据的两个预测公式，以估计混凝土的不稳定断裂韧性和初始断裂韧性。基于CCS测试的非线性断裂力学的结果看起来是可行的，并且很有希望。