石膏品种对硫铝酸钙-氧化钙类膨胀剂膨胀性能的影响研究

Study on the influence of gypsum type on the expansion properties of calcium sulphoaluminate-calcium oxide expansive agent

采用硫铝酸钙-氧化钙类膨胀剂熟料,通过测试胶砂试块的限制膨胀率以及膨胀收缩落差率,研究了水养转干空、绝湿以及温度匹配+绝湿3种不同养护条件下,硬石膏、二水石膏2种石膏对膨胀剂膨胀性能的影响。结果表明:在水养转干空情况下,二水石膏制备的膨胀剂限制膨胀率以及后期膨胀收缩落差率都优于硬石膏;在绝湿条件以及温度匹配+绝湿条件下,硬石膏制备的膨胀剂限制膨胀率以及后期膨胀收缩落差率都优于二水石膏,但相比于水养转干空条件,2种石膏制备的膨胀剂膨胀性能都出现一定程度的降低;相比于绝湿条件,采用温度匹配后,2种石膏制备的膨胀剂膨胀性能都有一定程度提高,但后期膨胀收缩落差率明显高于其它2种养护条件。

In this paper,calcium sulphoaluminate-calcim oxide expansive agent clinker was used to study the influence of anhydrite and dihydrate gypsum on the expansion performance of the expansive agent under three different curing conditions,namely,water curing to dry air,absolute humidity and temperature matching+absolute humidity,by measured the limited expansion rate and expansion shrinkage drop rate of mortars.The results indicated:under the condition of water curing to dry air,the limited expansion rate and expansion shrinkage drop rate,which prepared by dihydrate gypsum,was better than that prepared by anhydrite;under the condition of absolute humidity and the condition of temperature matching+absolute humidity,the limited expansion rate and expansion shrinkage drop rate,which prepared by anhydrite was better than that prepared by dihydrate gypsum.However,compared with the water curing to dry air,the expansion properties pf expansive agents,which prepared by the two types of gypsum,were reduced to a certain extent under the conditions of absolute humidity and temperature matching+absolute humidity.Compared with the conditions of absolute humidity,the expansion properties of the expansive agents that prepared by the two types of gypsum was improved to a certain extent by using temperature matching,and the expansion performance of anhydrite expansive agent was better,but the expansion shrinkage drop rate of the expansive agents,which prepared by the two types of gypsum,both were significantly higher than that of the other two curing conditions.