复合激发剂调控碱激发材料收缩性能研究  

Study on the shrinkage property of alkali-activated materials regulated by composite activator

作　　者：范小春[1] 张宇 高旭 汪阳 叶蛟龙[1,3] FAN Xiaochun;ZHANG Yu;GAO Xu;WANG Yang;YE Jiaolong(School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China;Sanya Science and Education Innovation Park,Wuhan University of Technology,Sanya 572000,China;Construction YIPIN Investment and Development Co.,Ltd,Wuhan 430074,China)

机构地区：[1]武汉理工大学土木工程与建筑学院,湖北武汉430070 [2]武汉理工大学三亚科教创新园,海南三亚572000 [3]中建壹品投资发展有限公司,湖北武汉430074

出　　处：《混凝土》2024年第9期79-84,共6页Concrete

基　　金：国家自然科学基金面上项目(41972271);武汉理工大学三亚科教创新园开放基金(2021KF0001)。

摘　　要：为改善碱激发矿渣-粉煤灰(AASF)胶凝材料的高收缩特性,通过硅酸钠(NS)分别与碳酸钠(SC)、硫酸钠(SS)和磷酸钠(SP)复掺制备复合激发剂,研究复合激发剂对AASF干燥收缩行为的影响。结果表明:复合激发剂对AASF体系的干燥收缩具有显著的抑制作用,其中SC15、SS15和SP5(Na2O质量取代率分别为15%、15%和5%)的90 d干燥收缩相较于NS分别降低39.0%、33.3%、42.4%,SP的综合减缩效果最好。SC使水化产物中生成了碳酸钙,而SS和SP的掺入并未引入新的晶体类水化产物,但SC、SS、SP可以有效减少体系中的自由水含量并提高化学结合水含量。SC、SS和SP的掺入均可以显著降低中孔体积比例和孔隙率,其中SC15、SS15、SP15的中孔体积率相较于NS分别降低30.8%、36.3%、25.0%。复合激发剂的减缩作用主要表现在两方面:一是显著提高化学结合水含量并抑制蒸发失水;二是有效减小中孔体积率以缓解毛细管应力,同时降低整体孔隙率以提高基质微观结构的致密程度。此外,掺入复合激发剂的各组试样也具有良好的工作性能和力学性能,其流动度和28 d抗压强度分别维持在181 mm和60 MPa以上。To improve the high shrinkage property ofalkali activated slag fly ash(AASF)cementitious material,the composite activator was prepared by mixing sodium silicate(NS)with sodium carbonate(SC),sodium sulfate(SS)and sodium phosphate(SP)respectively,and the influence of the composite activator on the drying shrinkage behavior of AASF was studied.The results showed that the composite activator had a significant inhibitory effect on the drying shrinkage of AASF system.The 90 day drying shrinkage of SC15,SS15 and SP5(The mass substitution rate of Na20 is 15%,15%and 5%respectively)decreased by 39.0%,33.3%and 42.4%respectively compared with NS,and SP had the best comprehensive shrinkage reduction effect.SC led to the generation of calcium carbonate in the hydration products,while the addition of SS and SP did not introduce new crystalline hydration products,but SC,SS,and SP could effectively reduce the evaporable water content and significantly increase the content of chemically bound water in the system.The incorporation of sC,sS and SP can significantly reduce the mesopore volume ratio and porosity.The mesopore volume ratio of SC15,SS15 and SP15 is 30.8%,36.3%and 25.0%lower than that of NS,respectively.The shrinkage reducing effect of compound activator is mainly shown in two aspects:one is to significantly increase the content of chemically bound water and inhibit evaporation loss;The other is to reduce the volume fraction of mesopore effectively to relieve capillary stress,and reduce the overall porosity to improve the compactness of matrix microstructure.ln addition,each group of samples mixed with composite activator also has good working performance and mechanical properties,and their fluidity and 28 d compressive strength are maintained above 181 mm and 60 MPa respectively.

关 键 词：碱激发 复合激发剂 干燥收缩 物相组成 孔隙结构 

分 类 号：TU528.042[建筑科学—建筑技术科学]