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最近,国家迠筑材料工业总局发布了《粉(?)灰砖》部标准(JC239—77),定于1978年10月1日实施。该标准由北京市迠筑材料科学研究所和河南迠筑工程材料科学研究所起草,北京市迠筑材料工业局提出的。这个部颁标准有以下三个特点:1、采纳了综合考虑标号和外观两项指标,以标号为主的方法,按照强度分为150、100和75三个标号。100号以上外观合格的为一等砖,75号的外观合乎要求的为二等砖,标号不足75号或外观不合格者为等外砖。这样有利于促进提高粉(?)灰砖的强度,对于外观也未降低要求。2、强度抽样检验的数据处理,采用的是“平均值—复合最小值方案”,主要优点是判断精确度比较高,错判机会比我国粘土砖、灰砂砖标准采用的“平均值—最小值方案”要小将近一倍,而且应用方便,容易掌握。3、采用了新的抗冻性试验方法,即“破坏面积法”,此法的优点是比较接近地反映了粉(?)灰砖受冻融循环后的破坏特点和实际使用情况。现将《粉(?)灰砖》部标准(JC239—77)全文转载如下。
Recently, the State Administration of Building Materials Industry issued the “Powder (?) Gray Brick” standard (JC239-77), which is scheduled to be implemented on October 1, 1978. The standard was drafted by the Beijing Institute of Building Materials Science and the Henan Science and Technology Institute for Materials Engineering, and proposed by the Beijing Municipal Bureau of Building Materials Industry. This ministerial standard has the following three characteristics: 1. Adoption of a comprehensive consideration of the label and appearance of the two indicators, the label-based method, according to the intensity is divided into 150,100 and 75 three labels. No. 100 and above are qualified as first-class bricks, No. 75 is as good as second-grade bricks, and the number is less than 75, or appearance is unfavorable. This is conducive to promoting the strength of powder (?) gray bricks, but also does not reduce the appearance of the requirements. 2. The data processing of intensity sampling inspection adopts the “average-composite minimum program”. The main advantage is that the judgment accuracy is relatively high, and the misjudgment opportunity is better than the “average-minimum” adopted by the Chinese clay brick and lime-sand brick standards. The “value scheme” is nearly twice the number of young people, and it is easy to use and easy to grasp. 3. A new test method for frost resistance is adopted, namely the “destruction area method”. The advantage of this method is that it closely reflects the damage characteristics and practical use of the powder (?) gray brick after freeze-thaw cycles. The full text of the “Powder (?) Gray Brick” standard (JC239-77) is reproduced below.