构件的实际尺寸决定了砼用量。规范对不同的砼构件尺寸都规定了不同的正负公差值,相应地形成了公差体积,而实际出现的偏差值,则形成了构件的波动体积。当偏差值分布在负公差范围内时,构件体积就小于设计体积,节省了砼用量,故称为用量节省。由此,负公差范围,称为用量节省区,发生在该区内的偏差点,称为节省点。当负偏差值超出允许范围时,虽然构件体积减少了砼用量,但是有害于构件设计能力,是规范所不允许的,故称为事故伤害。由此,负公差以下的范围,称为事故伤害区,发生在该区内的偏差点,称为伤害点。当偏差值分布在正公差范围内时,构件体积就大于设计体积,增加了砼用量,故称为用量损失。由此, The actual size of the component determines the amount of hydrazine. The specification stipulates different positive and negative tolerance values ​​for different crucible component dimensions, correspondingly forming a tolerance volume, and the actually occurring deviation value forms the fluctuating volume of the component. When the deviation value is distributed within the negative tolerance range, the volume of the component is smaller than the design volume, and the amount of hydrazine is saved. Therefore, it is called as the amount of usage savings. Therefore, the negative tolerance range, which is called the consumption saving area, occurs in the deviation point in the area and is called the saving point. When the negative deviation value exceeds the allowable range, although the volume of the component is reduced by the amount of helium, it is detrimental to the design capability of the component and is not allowed by the specification. Therefore, it is called an accidental injury. Therefore, the range below the negative tolerance is called the accident damage zone, and it is the deviation point in this zone, which is called the damage point. When the deviation value is distributed within the positive tolerance range, the volume of the component is larger than the design volume, and the amount of helium is increased, so it is called the loss of usage. thus,