改性剂对砂加气混凝土基体材料性能及微观结构

关键字：加气混凝土,基体材料,力学性能,干燥收缩,托勃莫

（1.盐城工学院 材料学院，江苏 盐城  224000；2河海大学 力学与材料学院，江苏 南京  210098）

　   摘要：通过正交试验优选了砂加气混凝土基体材料的配合比，采用活性硅铝改性剂改善加气混凝土基体材料的性能和微观结构。结果表明：基体材料的最优配合比为：CaO/SiO2摩尔比为0.70，m（水泥）∶m（石灰）=0.65，石膏掺量2.25%，水料比0.30。当添加11%活性铝硅改性剂时，抗折强度和抗压强度较空白样分别提高了24.6%和16.5%，同时28 d收缩值减小至0.213 mm/m。通过XRD和SEM分析得出，掺入改性剂后，Al3+进入C-S-H中，形成新相C-A-S-H；同时托勃莫来石晶体结晶完整，网络结构致密。
    关键词：加气混凝土；基体材料；力学性能；干燥收缩；托勃莫来石
    中图分类号：TU55+1.33        文献标识码：A        文章编号：1001-702X（2017）02-0117-04

Effects of modifier on aerated concrete properties and microstructure
HUANG Qi1，XIANG Qiudi2，JIANG Yaqing2，JIAO Baoxiang1
（1.School of Materials Engineering，Yancheng Institute of Technology，Yancheng 224000，China；
2.College of Mechanics and Meterials，Hohai University，Nanjing 210098，China）

    Abstract：The mix proportion of basis material of the sand aerated concrete was optimized by orthogonal tests，and the modifiers was used to improve the properties and microstructure of aerated concrete. The result showed that the optimum mixture of matrix is：molar ratio of CaO/SiO2 is 0.70，mass ratio of cement to lime is 0.65，mass ratio of gypsum is 2.25%，mass ratio of water to raw materials is 0.30. When adding 11% active aluminum-silicon modifier，the flexural strength and compressive strength of samples were increased by 24.6% and 16.5% respectively，while the shrinkage decreased to 0.213 mm/m. The XRD and SEM analysis shows that after mix with modifier，Al3+ was doped into C-S-H and new phase C-A-S-H formed. While tobermorite crystallized perfectly，and the network structure is dense.
    Key words：aerated concrete，basis materials，mechanical properties，dry shrinkage，tobermorite