矿粉-粉煤灰-偏高岭土地聚物的性能研究  

Study on Properties of Mineral Powder-fly Ash-metakaolin Geopolymers

作　　者：李铁铮 LI Tiezheng(Huaxin College of Hebei GEO University,Shijiazhuang 050700,China)

机构地区：[1]河北地质大学华信学院,河北石家庄050700

出　　处：《石家庄铁道大学学报(自然科学版)》2025年第1期84-90,共7页Journal of Shijiazhuang Tiedao University(Natural Science Edition)

摘　　要：地聚物是一种环境友好型胶凝材料,具有低能耗、低碳排等优点。采用偏高岭土、粉煤灰和矿渣为前驱体,水玻璃和氢氧化钠的混合物为碱激发剂,制备了一种高强度、微收缩的矿粉-粉煤灰-偏高岭土地聚物。研究了水胶比、碱激发剂的碱含量和模数对地聚物流动性、凝结时间、抗压强度和干缩性能的影响,并结合微观测试手段探讨了复合胶凝体系形成的微观机理。结果表明,水胶比对地聚物流动性、凝结时间与干缩性能的影响最大;碱含量是影响地聚物强度的最显著因素。当水胶比为0.32、碱激发剂的碱含量和模数分别为8%和1.25时,地聚物3 d和28 d抗压强度分别达到了39.0 MPa和62.0 MPa,56 d收缩值稳定在4.5×10^(-4)左右。碱激发剂激发粉体活化,溶解形成活性[SiO_(4)]^(4-)并聚合成凝胶,大量莫来石结构的C-(A)-S-H凝胶与少量的CaCO_(3)晶体相互交织形成致密的硬化结构,从而赋予地聚物高强度、微收缩的性能。Geopolymer is an environmentally friendly cementing material with the advantages of low energy consumption and low carbon emission.Using metakaolin,fly ash and slag as precursors,water glass and sodium hydroxide mixture as alkali activator,a high strength and micro-shrinkage slag-flyash-metakaolin geopolymer was prepared.The effects of water-binder ratio,alkali content and modulus of alkali activator on the fluidity,setting time,compressive strength and dry shrinkage of the geopolymers were studied.The microscopic mechanism of the composite gelling system was explored by combining micro testing methods.The results show that the water-binder ratio has the greatest influence on the fluidity,setting time and dry shrinkage of the geopolymer.Alkali content is the most significant factor affecting the strength of geopolymer.When the water-binder ratio is 0.32 and the alkali content and modulus of the alkali activator are 8% and 1.25,respectively,the 3 d and 28 d compressive strength of the geopolymer reaches 39.0 MPa and 62.0 MPa,respectively,and the shrinkage value is stable at about 4.5×10^(-4) at 56 d.Alkali activator activates the powder,dissolves to form active[SiO_(4)]^(4-)and polymerizes into gels.A large amount of C-(A)-S-H gel are intermixed with a small amount of CaCO_(3) crystal to form a dense hardened structure,which endows the geopolymer with high strength and micro-shrinkage properties.

关 键 词：地聚物 力学性能 干缩性能 机理分析 

分 类 号：TQ528.41[化学工程—煤化学工程]