NaAlO_(2)激发石灰石粉的净浆中胶凝物相表征  

Characterization of Cementitious Phase in NaAlO_(2)-Activated Limestone-based Paste

作　　者：刘源涛 董必钦[1] 洪舒贤 王琰帅 房国豪 LIU Yuantao;DONG Biqin;HONG Shuxian;WANG Yanshuai;FANG Guohao(Shenzhen Key Laboratory for Lowcarbon Construction Material and Technology,Guangdong Province Key Laboratory of Durability for Marine Civil Engineering,College of Civil and Transportation Engineering,Shenzhen University,Shenzhen 518060,Guangdong,China)

机构地区：[1]深圳大学土木与交通工程学院,广东省滨海土木工程耐久性重点实验室,深圳市低碳建筑材料与技术重点实验室,广东深圳518060

出　　处：《材料导报》2024年第13期134-139,共6页Materials Reports

基　　金：国家自然科学基金(52108228,51925805)。

摘　　要：石灰石粉在水泥基材料中活性较低。然而,采用NaAlO_(2)作为激发剂,可以制备性能较好的石灰石粉基胶凝材料。为深入研究NaAlO_(2)激发石灰石粉的净浆中的胶凝物相,明晰其性能形成机理,本工作对比分析了NaAlO_(2)激发(D1)与NaOH、Al(OH)_(3)按1∶1的物质的量比复配激发(D2)的反应进程、产物占比、力学性能、微观结构特征。试验结果表明,D1与D2均出现了两个放热峰。第一个峰对应着激发剂溶解,第二个峰与单碳型碳铝酸钙(Mc)生成有关。D1中Mc的结晶进程快于D2中的,其第二个放热峰出现时间比D2早。D1中,部分NaAlO_(2)生成了Mc,其他被消耗部分没有形成晶体产物,而是形成介于晶体与无定形状态之间的微晶AH_(3)相。透射电镜(TEM)结果表明,微晶AH3相呈现出衍射斑点零星分布于同心圆环上的衍射特征,其颗粒尺寸比三水铝石(Gibbsite)小,具有更好的胶凝特性。养护28 d后,D1(22.80 MPa)的抗压强度显著高于D2(0.95 MPa),表明AH_(3)相是NaAlO_(2)激发石灰石粉的净浆中的重要胶凝物相。Limestone has a low reactivity in cement-based material.However,when NaAlO_(2)is used as the activator,the limestone-based cementitious material with good property can be fabricated.Aiming to further analyze the cementitious phase in the NaAlO_(2)-activated limestone paste and clarify the formation mechanism of its property,the reaction process,product proportion,mechanical property and microstructure characteristic of D1(activated by NaAlO_(2))and D2(activated by the mixture of NaOH and Al(OH)_(3) at a 1∶1 molar ratio)were compared and analyzed in this work.The experimental results showed that both D1 and D2 contained two exothermic peaks.The first peak corresponded to the dissolution of the activator,and the second peak was related to the formation of monocarboaluminate(Mc).The crystallization process of Mc in D1 was faster than that in D2,and the second exothermic peak appeared earlier in D1 than that in D2.In D1,partial NaAlO_(2)formed Mc.The other consumed part did not form crystal products.They formed the microcrystalline AH_(3) phase which was between crystal and amorphous state.Transmission electron microscopy(TEM)results indicated that the microcrystalline AH_(3) phase exhibited the diffraction characteristics of scattered diffraction spots on concentric rings.It had a smaller particle size than gibbsite and yielded a better cementitious characteristic.After curing 28 d,the compressive strength of D1(22.80 MPa)was significantly higher than that of D2(0.95 MPa),indicating that AH_(3) phase was an important cementitious phase in the NaAlO_(2)-activated limestone paste.

关 键 词：石灰石粉 NaAlO_(2) 反应进程 胶凝性能 AH3相 

分 类 号：TU526[建筑科学—建筑技术科学]