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一、混凝土试配强度混凝土是一种多相非匀质材料,其抗压强度的分布规律是服从正态分布的.分布曲线(图1)的特征可直接用强度标准差σ(或变异系数Cv)表示出来.当质量控制良好时,强度值聚集于平均值的近旁,σ值小,曲线高而窄;当质量控制不良时,强度值分散,σ值大,曲线低而宽.标准正态频率分布曲线X～N(0.1)与横坐标之间的全部面积即为概率总和等于1,曲线与横坐标之间的各部分的面积为混凝土强度落在该范围内的概率.P%称
First, the strength of concrete test concrete is a multi-phase non-homogeneous material, the distribution of its compressive strength is subject to normal distribution. Characteristics of the distribution curve (Figure 1) can be used directly with the standard deviation of strength σ (or coefficient of variation) Cv) is expressed. When the quality control is good, the intensity values are gathered near the mean value, the σ value is small, the curve is high and narrow; when the quality control is bad, the intensity value is dispersed, the σ value is large, and the curve is low and wide. The total area between the state frequency distribution curve X N N (0.1) and the abscissa is the sum of the probabilities equal to 1, and the area of each part between the curve and the abscissa is the probability that the concrete strength falls within this range.