Zhang Zhipeng, Jia Yanmin, Liu Jinliang
School of Civil Engineering, Northeast Forestry University, Harbin 150040, China.
Materials (Basel). 2022 Apr 7;15(8):2714. doi: 10.3390/ma15082714.
In order to study the influence law of each parameter on the performance of the alkali-activated composite gelling system, the influence degree was sorted, and the most important parameter affecting each performance was found. The solution of liquid water glass and solid sodium hydroxide was used as the alkaline activator, and the mixing ratio was designed by the orthogonal test method. The effects of four parameters of fly ash content, water glass modulus, water glass solid content, and water-solid ratio on the working performance and mechanical properties of alkali-activated slag-fly ash composite cementation system were discussed. The gelling system was studied by microscopic experiments such as SEM and FTIR. The results show that the solid content of water glass has the greatest influence on the fluidity of the composite cementitious system, and the content of fly ash is the primary factor affecting the setting time of the material. The flexural and compressive strengths at the age of 7 d and 28 d were most affected by the content of fly ash, and the solid content of water glass had the greatest influence on the flexural and compressive strengths at the age of 2 d. From the perspective of microscopic morphology, in the high-strength samples, the fly ash particles and the remaining outer shell are embedded in the gel to form a dense whole. When the amount of silica in the composite gelling system is too high, it will cause the phenomenon of low macroscopic mechanical properties.
为研究各参数对碱激发复合胶凝体系性能的影响规律，对影响程度进行排序，找出影响各项性能的最重要参数。以液体水玻璃和固体氢氧化钠的溶液作为碱性激发剂，采用正交试验法设计配合比。探讨了粉煤灰掺量、水玻璃模数、水玻璃固含量和水固比四个参数对碱激发矿渣-粉煤灰复合胶凝体系工作性能和力学性能的影响。通过扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）等微观试验对该胶凝体系进行研究。结果表明，水玻璃固含量对复合胶凝体系的流动性影响最大，粉煤灰掺量是影响材料凝结时间的主要因素。7 d和28 d龄期的抗折和抗压强度受粉煤灰掺量影响最大，水玻璃固含量对2 d龄期的抗折和抗压强度影响最大。从微观形貌来看，在高强度试样中，粉煤灰颗粒及其剩余外壳嵌入凝胶中形成致密整体。当复合胶凝体系中二氧化硅含量过高时，会出现宏观力学性能偏低的现象。
