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以团聚粒径很大的沉淀二氧化硅(PS)和团聚粒径较小的纳米二氧化硅(NS)为原材料,研究了纳米二氧化硅团聚特性对水泥水化硬化特性的影响。结果表明:与NS相比,虽然PS团聚粒径很大,后期火山灰活性较低,其早期火山灰活性却较大,对水泥水化的促进作用也更明显。扫描电子显微镜分析表明,NS和PS的火山灰反应产物的胶结作用有限,其与水泥水化产物本体之间甚至存在明显的界面过渡区。压汞分析表明:掺PS和NS均可有效降低硬化水泥石毛细孔率;与掺PS相比,掺NS对减小20 nm～10μm的凝胶孔和毛细孔体积更有利。掺纳米二氧化硅对硬化水泥石微观结构的影响主要是由于团聚颗粒对水泥分散体系的填充效应和吸水效应所致,与晶核效应无关。
Abstract：Effect of nano-silica agglomeration on the hydration and hardening of cement was investigated by using precipitated silica(PS) with much larger agglomerates and nano-silica(NS) powder with much smaller ones as additives.The results reveal that the PS exhibits a higher pozzolanic reactivity at early ages and a better accelerating effect on the cement hydration though it possesses some larger agglomerates and a little lower pozzolanic reactivity at late ages rather than NS.The observation by scanning electron microscopy indicates that the cementitious property of the pozzolanic C-S-H gels from the agglomerates was limited.There even existed an interfacial transition zone between the reacted agglomerates and bulk hardened cement paste(HCP).The MIP results show that the NS addition can reduce the capillary and the gel pore of the HCP in the range of 20 nm-10 μm more effectively,compared to the PS addition.It is suggested that the effect of nano-silica addition on the microstructure improvement of the HCP could be resulted from the filling and water adsorbing effects of the agglomerates in the powder rather than the seeding effect.
[1]SOBOLEV K,GUTIéRREZ M F.How nanotechnology can changethe concrete world[J].Am Ceram Soc Bull,2005,84(10):14–18,84(11):16–20.
[2]叶青.硅溶胶对水泥基材料微观结构和力学性能的影响[J].硅酸盐学报,2008,36(4):1–6.YE Qing.J Chin Ceram Soc,2008,36(4):1–6.
[3]JO Byung-Wan,KIM Chang-Hyun,TAE Ghi-ho,et al.Characteristicsof cement mortar with nano-SiO2 particles[J].Constr Build Mater,2007,21:1351–1355.
[4]LI Hui,ZHANG Maohua,OU Jinping.Abrasion resistance of concretecontaining nano-particles for pavement[J].Wear,2006,260:1262–1266.
[5]LI Zhenhua,WANG Huafeng,HE Shan,et al.Investigations on thepreparation and mechanical properties of the nano-alumina reinforcedcement composite[J].Mater Lett,2006,60:356–359.
[6]JI Tao.Preliminary study on the water permeability and microstructureof concrete incorporating nano-SiO2[J].Cem Concr Res,2005,35(10):1943–1947.
[7]TIKALSKY P J,SCHEETZ B E,GARVEY J J.Long-term influence ofalkaline earth silicate admixtures on the microstructural developmentof structural concrete[C]//Proc Twenty-First Int Conference on CemMicroscopy,Las Vegas,NV,1999,266–272.
[8]GAITERO J J,CAMPILLO I,GUERRERO A.Reduction of the calciumleaching rate of cement paste by addition of silica nanoparticles[J].Cem Concr Res,2008,38:1112–1118.
[9]DOLADO J S,CAMPILLO I,ERKIZIA E,et al.Effect of nanosilicaadditions on belite cement pastes held in sulfate solutions[J].J AmCeram Soc,2007,90(12):3973–3976.
[10]ZHANG Mao-hua,LI Hui.Pore structure and chloride permeability ofconcrete containing nano-particles for pavement[J].Constr BuildMater,2011,25:608–616.
[11]王冲,蒲心诚,刘芳,等.纳米颗粒材料在水泥基材料中应用的可行性研究[J].新型建筑材料,2003(2):22–23.WANG Chong,PU Xincheng,LIU Fang,et al.New Build Mater(inChinese),2003(2):22–23.
[12]KORPA A,KOWALD T,TRETTIN R.Hydration behaviors,structureand morphology of hydration phases in advanced cement-based systemscontaining micro and nanoscale pozzolanic additive[J].Cem ConcrRes,2008,38(7):955–962.
[13]KIRBY G H,LEWIS J A.Comb polymer architecture effects onrheological property evolution of concentrated cement suspensions[J].J Am Ceram Soc,2004,87(9):1643–1652.
[14]孔德玉,叶青,倪彤元,等.溶胶法引入纳米SiO2对水泥浆流变性能的影响及机制[J].稀有金属材料与工程,2010,39(S2):451–454.KONG Deyu,YE Qing,NI Tongyuan,et al.Rare Metal Mater Eng(inChinese),2010,39(S2):451–454.
[15]BJ RNSTR M J,MARTINELLI A,MATIC A,et al.Acceleratingeffects of colloidal nano-silica for beneficial calcium–silicate–hydrateformation in cement[J].Chem Phys Lett,2004,392:242–248.
[16]THOMAS J J,JENNINGS H M,CHEN J J.Influence of nucleationseeding on the hydration mechanisms of tricalcium silicate and cement[J].J Phys Chem C,2009,113(11):4327–4334.
[17]EISINAS A,BALTAKYS K,SIAUCIUNAS R.The effect of gyroliteadditive on the hydration properties of Portland cement[J].Cem ConcrRes,2012,42(1):27–38.
[18]杜祥飞,孔德玉,苑克江,等.掺纳米白炭黑对新拌和硬化水泥基材料性能的影响[J].浙江工业大学学报,2012,40(3):308–312.DU Xiangfei,KONG Deyu,YUAN Kejiang,et al.J Zhejiang UnivTechnol(in Chinese),2012,40(3):308–312.
[19]TENNIS P D,JENNINGS H M.A model for two types of calciumsilicate hydrate in the microstructure of Portland cement pastes[J].Cem Concr Res,2000,30(6):855–863.
基本信息:
DOI：10.14062/j.issn.0454-5648.2012.11.012
中图分类号:TU528
引用信息:
[1]孔德玉,杜祥飞,杨杨,等.纳米二氧化硅团聚特性对水泥水化硬化性能的影响[J].硅酸盐学报,2012,40(11):1599-1606.DOI:10.14062/j.issn.0454-5648.2012.11.012.
基金信息:
浙江省重点科技创新团队项目(2009R50022)资助
2012-10-31
2012-10-31
2012-10-31