长江口航道疏浚淤泥（砂）用于底层抹灰石膏的

关键字：长江口航道,疏浚淤泥（砂）,抹灰石膏,颗粒级配

（上海市建筑科学研究院，上海  200032；2.上海市公用事业学校，上海  200030）
 

    摘要：针对长江口航道疏浚淤泥（砂）特点，研究其应用于底层抹灰石膏的临界掺量、外加剂改性技术等。研究表明，疏浚淤泥（砂）可用于制备底层抹灰石膏。当疏浚淤泥（砂）过细、含泥量过大时，一方面将增加拌合物需水量，另一方面将使二水硫酸钙晶体与骨料界面结合不再紧密，从而降低硬化体强度。缓凝剂宜选用蛋白质类缓凝剂，保水剂宜选用中等黏度纤维素醚，其掺量应根据疏浚淤泥（砂）含泥量的增加而适当提高，并可配合掺入淀粉醚改善施工性能。
    关键词：长江口航道；疏浚淤泥（砂）；抹灰石膏；颗粒级配；含泥量
    中图分类号：TU526         文献标识码：A        文章编号：1001-702X（2017）05-0041-05

Research on Yangtze estuary waterway sand gypsum plaster for base coating
TAN Xiaoqing1，2
（1.Shanghai Research Institute of Building Sciences，Shanghai 200032，China；2.Shanghai Public Utility School，Shanghai 200030，China）

    Abstract：The paper researched the critical content and additives modification technology of gypsum plaster for base coating on the properties of Yangtze Estuary Waterway dredging sand. Research showed that Yangtze Estuary Waterway dredging sand could be used for the preparation of gypsum plaster for base coating，if the dredging sand had low fineness modulus or high clay content，which would result in mixture water demand increasing and no dense bonding interface between calcium sulphate dihydrate and aggregate，plaster layer strength would be reduced. Proteins retarder was recommended for retarder. Medium viscosity cellulose ether was recommended for water retaining agent，whose dosage should be increased properly according to the dredging sand clay content. Starch ethers were recommended to improve the workability.
    Key words：Yangtze estuary waterway，dredging sand，gypsum plaster，grain composition，clay content