Ullmann Stefan, Nordsiek Sven, Lowke Dirk
Institute of Building Materials, Concrete Construction and Fire Safety (iBMB), Technische Universität Braunschweig, 38106 Braunschweig, Germany.
Materials (Basel). 2022 Sep 1;15(17):6050. doi: 10.3390/ma15176050.
In order to evaluate the influence of certain experimental or material-related conditions on results of the rapid chloride migration test (RCM test), statistical tests within and between samples are necessary. Thus, it needs to be clear which scatter a sample or a population of results is already subjected to without external influences due to the test method itself. So far, however, literature values for the appropriate statistical variable (coefficient of variation, CoV) explicitly valid for mortar or fine-grained concrete, e.g., for concrete repair, are missing. Therefore, we suggest a specific mortar CoV based on our own results of RCM tests performed on a cement-rich, sprayable mortar based on ordinary Portland cement. For the evaluation of external influences on a sample in comparison to a reference sample, we developed a significance criterion based on a statistical hypothesis test. The sensitivity and the reliability of this criterion is demonstrated on various results from RCM tests on mortar specimens, according to the test specifications and with deliberately chosen deviations from it. In addition, we point out the parameters included in the calculation of the rapid chloride migration coefficient that are the most sensitive to unintentional errors.
为了评估某些实验或材料相关条件对快速氯离子迁移试验（RCM试验）结果的影响，有必要对样品内部和样品之间进行统计检验。因此，需要明确在没有因试验方法本身产生的外部影响的情况下，一个样品或一组结果已经受到了何种离散程度的影响。然而，到目前为止，对于适用于砂浆或细粒混凝土（例如用于混凝土修复）的合适统计变量（变异系数，CoV）的文献值尚不存在。因此，我们基于对一种基于普通硅酸盐水泥的富水泥、可喷涂砂浆进行的RCM试验结果，提出了一个特定的砂浆CoV。为了评估与参考样品相比外部因素对一个样品的影响，我们基于统计假设检验制定了一个显著性标准。根据试验规范并故意设置与规范的偏差，在对砂浆试件进行的RCM试验的各种结果上证明了该标准的敏感性和可靠性。此外，我们指出了快速氯离子迁移系数计算中对无意误差最敏感的参数。
