NaOH激发矿渣胶凝材料的^(29)Si NMR研究

^(29)Si NMR Study of NaOH-Activated Slag Cementitious Materials

为研究NaOH激发矿渣胶凝材料的强度演变规律及反应机理,采用抗压强度测试、XRD和^(29)Si NMR等技术手段探究了NaOH用量对碱矿渣胶凝材料抗压强度、水化产物种类、矿渣水化反应程度、C-S-H凝胶的聚合程度及其Al/Si的影响。研究结果表明:当NaOH用量为6%时,碱激发矿渣胶凝材料的抗压强度达到最大值; XRD谱图显示,NaOH激发矿渣胶凝材料的主要水化产物为C-S-H凝胶;^(29)Si NMR分析结果表明,NaOH用量的增加促进了矿渣的水化,其最佳用量为6%左右,NaOH用量超过6%,会降低C-S-H凝胶的聚合程度及其Al/Si,对胶凝材料的强度产生不利影响。

In order to to investigate the strength evolution and reaction mechanism of NaOH-activated slag cementitious materials,compressive strength test,XRD and 29Si NMR analysis techniques were used to investigate the effect of NaOH dosage on the compressive strength,the hydration product types,hydration reaction degree of slag,the polymerization degree and Al/Siratio of C-S-H gels.The results show that the compressive strength of alkali-activated slag cementitious materials reached the maximum value when the NaOH dosage was controlled as 6%;XRD patterns show that the main hydration product of NaOH-activated slag cementitious materialsis C-S-H gels.The results of 29Si NMR analysis show that the increase of NaOH dosage promotes the hydration of slag,and the optimum dosage is about 6%.When the dosage of NaOH exceeds 6%,the degree of polymerization of C-S-H gels and its Al/Si will be reduced,which adversely affects the strength of the cementitious materials.