三聚氰胺减水剂对碱激发超细偏高岭土基地质聚合物流动性和力学性能的影响

Effect of Melamine Water Reducer on Fluidity and Mechanical Properties of Alkali-Activated Ultrafine Metakaolin Based Geopolymer

以超细偏高岭土(UMK)为原材料,研究了三聚氰胺减水剂(MWR)对碱激发偏高岭土基地质聚合物的流动性能和力学性能的影响。采用流变学方法表征地聚物净浆的流动性,结合凝结时间实验、含水率实验和力学性能实验研究了MWR在地质聚合反应中的作用。通过SEM、FTIR和XRD等分析手段研究反应产物的微观形貌、化学结构和矿物组成,以揭示MWR的作用机理。结果表明,MWR与UMK相容性不好,MWR掺量为2wt%和4wt%时对地聚物净浆的流动性有一定改善,但掺量6wt%时明显促进了净浆的流动度损失。MWR的掺入改变了地聚物的孔隙结构,促进了水分的散失,从而使抗压强度随MWR掺量的增大而先减小后有所回升。

Ultrafine metakaolin(UMK)was used as raw material to study the effect of melamine water reducer(MWR)on the fluidity and mechanical properties of alkali-activated metakaolin based geopolymer.The fluidity of geopolymer slurry was characterized by rheological method,and the effect of MWR on the reaction was also studied via tests for setting time,moisture content and mechanical property.The micromorphology,chemical structure and mineral composition of the geopolymer were studied with SEM,FTIR and XRD analysis to reveal the reaction mechanism of MWR in UMK based geopolymer.The results show that the MWR has poor compatibility with UMK,and MWR dosage of 2wt%and 4wt%improve the fluidity of the slurry to some extent,while 6wt%promote the fluidity loss obviously.MWR changes the pore structure of the geopolymer and promotes the loss of water,so that the compressive strength decreases at first and then increases with the increase of MWR dosage.