- 目录
- 建筑石膏与胶凝材料
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高强石膏基胶凝材料配合比设计及冻融和耐水性能研究
作者：李晓东1，杨林1，宋子阳1，刘晨2
（1.兰州理工大学 土木工程学院，甘肃 兰州 730050；2.兰州市城市建设设计院，甘肃 兰州 730030）
摘要：为研究高强石膏基胶凝材料的冻融及软化性能，利用三因素五水平正交试验对高强石膏、粉煤灰、矿渣的最佳配合比进行了强度试验。试验中取高强石膏掺量、粉煤灰掺量和水胶比为3个因素研究了胶凝材料的7、28 d的基本力学性能。并对最优配合比下的胶凝材料试件进行了水化反应机理分析、微观形貌分析、冻融试验与软化试验。结果表明：高强石膏、粉煤灰、矿渣的最佳配合比为44∶34∶22，最佳水胶比为0.3；纳米材料适量替代高强石膏可减小冻融循环强度损失；纤维与纳米材料的掺入使得试件的软化系数增大；胶凝材料的最终水化产物为钙钒石；试件受力破坏时断面整齐，致密的C-H-S胶凝材料层叠于试件内部。
关键词：高强石膏；配合比；正交试验；冻融试验；软化试验；矩阵分析法
中图分类号：TU528 文献标识码：A 文章编号：1001-702X（2022）12-0062-05
Research on freeze-thaw and softening properties based on the design of high-strength gypsum-based cementitious materials
LI Xiaodong1，YANG Lin1，SONG Ziyang1，LIU Chen2
（1.College of Civil Engineering，Lanzhou University of Technology，Lanzhou 730050，China；
2.Urban Construction Design Institute of Lanzhou，Lanzhou 730030，China）
Abstract：In order to study the freeze-thaw and softening properties of high-strength gypsum-based cementitious materials，the strength test of the optimal mix ratio of high-strength gypsum，fly ash，and slag was carried out using three-factor five-level orthogonal test. In the experiment，the content of high-strength gypsum，the content of fly ash，and the water-binder ratio were taken as three factors to explore the basic mechanical properties of cementitious materials for 7 d and 28 d. The hydration reaction mechanism analysis，microscopic morphology analysis，freeze-thaw test and softening test were carried out on the cementitious material specimen under the optimal mix ratio. Analysis and research show that the best mixing ratios of high-strength gypsum，fly ash，and slag are 44%，34%，and 22% respectively，and the best water-binder ratio is 0.3. An appropriate amount of nanomaterials can reduce the strength loss of freeze-thaw cycles. The blending of fibers and nanomaterials increases the softening coefficient of the specimen. The final product of the cementitious material is calcium vanadite. When the specimen is damaged by force，the section is neat，and the dense C-H-S cementitious material is laminated inside the specimen.
Key words：high-strength gypsum，optimal mix ratio，orthogonal test，freeze-thaw test，softening test，matrix analysis