水泥用基准混凝土外加剂标样的开发

Development of reference concrete admixture sample for cement

水泥与外加剂的相容性通常可以使用水泥净浆流动度、胶砂减水率、混凝土试验等方式进行测试,其中,水泥净浆流动度可以快速测试水泥与外加剂的相容性,是一种非常好的检测水泥与外加剂相容性的方法。旗下近百家水泥企业的某水泥集团,需使用一种外加剂标样,以对不同厂家、不同区域生产的水泥与外加剂的相容性进行质量管控。水泥用基准混凝土外加剂标样是一种特殊的外加剂,要求自身质量均一稳定,能够快速准确地反映水泥的产品质量,而且保质期要长达14个月以上(通常每年制样一次,因此要求保质期更长),远远超过国家标准对混凝土外加剂保质期6个月的要求。本文通过试验,筛选了最适合作为基准外加剂的聚羧酸母液品种,并通过调整外加剂标样的pH值和加入杀菌剂的方式,有效延长了外加剂标样的保质期。

The compatibility of cement and admixture is usually tested by methods of cement slurry fluidity,cement sand water reduction rate,concrete test.Among them,cement slurry fluidity can quickly test the compatibility of cement and admixture,which is a good test method of compatibility with cement and admixture.A cement group with nearly 100 enterprises needs to use an admixture standard sample to control the quality of the compatibility of cement produced and admixture by different manufacturers and regions.The reference sample of concrete admixture is a special admixture,which requires to meet the conditions of uniform and stable,and can quickly and accurately reflect the quality of cement products.The reference sample requires a shelf life of up to 14 months(the sample is usually prepared once a year,so it requires a longer shelf life),which far exceeds the national standard requirement of 6 months for shelf life of concrete admixture.In this paper,the most suitable polycarboxylic acid mother liquor varieties as the reference admixture were screened by the test,and the shelf life of the admixture samples was effectively extended by the methods of adjusting the pH of the admixture samples and adding fungicide.