粒径对偏高岭土基地聚物工作性能和力学强度的影响

Effect of particle size on workability and mechanical strength of metakaolin based geopolymers

通过复掺不同质量比的粗细2种原材料,制备不同粒径分布的偏高岭土,制备偏高岭土基地质聚合物;采用流变学和流动度测试方法,结合凝结时间测试和力学性能测试,研究原材料粒径对碱激发偏高岭土基地质聚合物的工作性能和力学强度的影响;采用形貌分析、等温吸附和傅里叶红外光谱等表征手段,对地聚物固化体的断面形貌、孔隙结构和反应程度进行表征。结果表明:偏高岭土粒径的增大可以明显提高地聚物净浆的流动性能,但同时显著延长了浆体的凝结时间。原材料粒径的增大使得地聚物固化体1 d的力学强度单调递减;固化体的3、7 d的力学强度没有明显的变化。

In this paper,metakaolin with different particle size distribution was prepared by mixing two kinds of raw materials with different mass ratios,then the metakaolin base polymer was prepared. Rheological and fluidity testing methods,combined with setting time test and mechanical property test,were used to study the influence of raw material particle size on the working properties and mechanical strength of alkali-excited metakaolin base polymer. Finally,morphology analysis,isothermal adsorption and Fourier transform infrared spectroscopy(FTIR) were used to characterize the cross-section morphology,pore structure and reaction degree of the geopolymer. The results show that the increase of metakaolin particle size can significantly improve the flow performance of the geopolymer slurry,but also significantly prolong the setting time of the slurry. With the increase of raw material particle size,the mechanical strength of geopolymer solidified body decreases monotonically for 1 d. The mechanical strength of the solidified body at 3 and 7 days did not show obvious change rule.