NaOH激发矿渣胶凝材料的~(29)Si NMR研究
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摘要
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 ~(29)Si 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 ~(29)Si 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.
In order to to investigate the strength evolution and reaction mechanism of NaOH-activated slag cementitious materials,compressive strength test,XRD and ~(29)Si 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 ~(29)Si 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.
引文
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[13]Zhang L,Chen B.Hydration and properties of slag cement activated by alkali and sulfate[J].Journal of Materials in Civil Engineering,2017,29(9):04017091.
[2]Rashad A M,Zeedan S R,Hassan A A.Influence of the activator concentration of sodium silicate on the thermal properties of alkali-activated slag pastes[J].Construction&Building Materials,2016,102(2):811-20.
[3]何晶,何建新.利用碱激发矿渣粉制备的土体固化剂的力学性能研究[J].新疆农业大学学报,2016,39(5):414-8.
[4]刘仍光,丁士东,阎培渝.NMR技术研究水泥-矿渣复合胶凝材料水化产物凝胶的微观结构[J].混凝土,2015(8):80-3.
[5]Brough A R,Atkinson A.Sodium silicate-based,alkali-activated slag mortars:Part I.Strength,hydration and microstructure[J].Cement&Concrete Research,2002,32(6):865-79.
[6]Hilbig H,Buchwald A.The effect of activator concentration on reaction degree and structure formation of alkali-activated ground granulated blast furnace slag[J].Journal of Materials Science,2006,41(19):6488-91.
[7]Khan M S H,Kayali O,editors.Effect of Na OH activation on ettringite in concrete containing ground granulated blast furnace slag[C].International Conference on Sustainable Construction Materials and Technologies,2013.
[8]Yang K H,Song J K.Workability loss and compressive strength development of cementless mortars activated by combination of sodium silicate and sodium hydroxide[J].Journal of Materials in Civil Engineering,2009,21(3):119-27.
[9]Song S,Sohn D,Jennings H M,et al.Hydration of alkali-activated ground granulated blast furnace slag[J].Journal of Materials Science,2000,35(1):249-57.
[10]Escalante-García J I,Fuentes A F,Gorokhovsky A,et al.Hydration products and reactivity of blast-furnace slag activated by various alkalis[J].Journal of the American Ceramic Society,2010,86(12):2148-53.
[11]Engelhardt G,Michel D.High-resolution solid-state NMR of silicates and zeolites[J].John Wiley&Sons New York Ny,1988,42(1):187-188.
[12]Richardson I G,Groves G W.The structure of the calcium silicate hydrate phases present in hardened pastes of white Portland cement/blastfurnace slag blends[J].Journal of Materials Science,1997,32(18):4793-802.
[13]Zhang L,Chen B.Hydration and properties of slag cement activated by alkali and sulfate[J].Journal of Materials in Civil Engineering,2017,29(9):04017091.