SiO_2气凝胶在混凝土中的稳定、分散与保温作用研究
|
摘要
气凝胶在混凝土中的稳定性和分散性是成功制备和发挥气凝胶/混凝土保温材料保温性能的关键。本文研究了在亲水性混凝土体系和机械搅拌作用下,通过调节和控制气凝胶表面的化学状态,制备了稳定的气凝胶/混凝土材料,研究了气凝胶与混凝土基体的相互作用以及其他重要因素对气凝胶结构稳定性的影响。用傅立叶变换红外光谱仪、热重分析、氮气吸附-解吸等温线、扫描电子显微镜、导热系数分析仪等对样品进行了表征。结果表明,表面活性剂通过调节和控制动力学参数,成功地附着在气凝胶表面。气凝胶颗粒在混凝土中稳定,并保持原有形状。随着气凝胶含量的增加,混凝土的导热系数逐渐减小。
The stability and dispersion of aerogels in concrete is the key to the successful preparation and application of aerogels/concrete insulation materials. In this paper, the stable aerogel/concrete material was prepared by adjusting and controlling the chemical state of aerogel surface under the action of hydrophilic concrete system and mechanical agitation. The interaction between aerogel and concrete matrix and other important factors on the stability of aerogel structure were studied. The samples were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis,nitrogen adsorption-desorption isotherm, scanning electron microscopy and thermal conductivity analyzer. The results showed that the surfactant was successfully adhered to the aerogel surface by adjusting and controlling the kinetic parameters. Aerogel particles were stable in concrete and retain their original shape. With the increase of aerogel content, the thermal conductivity of concrete decreased.
The stability and dispersion of aerogels in concrete is the key to the successful preparation and application of aerogels/concrete insulation materials. In this paper, the stable aerogel/concrete material was prepared by adjusting and controlling the chemical state of aerogel surface under the action of hydrophilic concrete system and mechanical agitation. The interaction between aerogel and concrete matrix and other important factors on the stability of aerogel structure were studied. The samples were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis,nitrogen adsorption-desorption isotherm, scanning electron microscopy and thermal conductivity analyzer. The results showed that the surfactant was successfully adhered to the aerogel surface by adjusting and controlling the kinetic parameters. Aerogel particles were stable in concrete and retain their original shape. With the increase of aerogel content, the thermal conductivity of concrete decreased.
引文
[1]H.S.Arel,Recyclability of waste marble in concrete production,J.Cleaner Prod.131(2016)17-188.
[2]J.De Brito,Abrasion resistance of concrete made with recycled aggregates,Int.J.Sustainable Eng.3(2010)58-64.
[3]W.She,Y.Du,C.W.Miao,J.P.Liu,G.T.Zhao,J.Y.Jiang,Y.S.Zhang,Application of organic-and nanoparticle-modifified foams in foamed concrete:Reinforcement and stabilization mechanisms,Cement Concrete Comp.106(2018)12-22.
[4]W.W.Guo,J.J.Liu,P.Zhang,L.Song,X.Wang,Y.Hu,Multi-functional hydroxyapatite/polyvinyl alcohol composite aerogels with selfcleaning,superior fire resistance and low thermal conductivity,Compos.Sci.Technol.158(2018)128-136.
[5]R.Baetens,B.P.Jelle,A.Gustavsen,Aerogel insulation for building applications:a state-of-the-art review,Energy Build.43(2011)761-769.S.L.Xu,J.H.Liu,Q.Zeng,Towards better characterizing thermal conductivity of cement-based materials:The effects of interfacial thermal resistance and inclusion size,Mater.Design,157(2018)105-118.
[6]A.Kan,R.Demirboga.A novel material for lightweight concrete production.Cem.Concr.Compos.31(2009)489-495.
[7]K.E.Parmenter,F.Milstein,Mechanical properties of silica aerogels,J.Non-Cryst.Solids 223(1998)179-189.
[8]K.A.D.Obrey,K.V.Wilson,D.A.Loy,Enhancing mechanical properties of silica
[9]aerogels,J.Non-Cryst.Solids 357(2011)3435-3441.
[10]T.Yang,H.J.Zhu,Z.H.Zhang,X.Gao,C.S.Zhang,Q.S.Wu,Effect of fly ash microsphere on the rheology and microstructure of alkaliactivated fly ash/slag pastes,Cement Concrete Res.109(2018)198-207.
[11]J.Kim,B.Kim,C.Anand,A.Mano,J.S.M.Zaidi,K.Ariga,J.You,A.Vinu,E.Kim,A Single-Step Synthesis of Electroactive Mesoporous Prodot-Silica Structures.Angew.Chem.-Int.Ed.54(2015)8407-8410.
[2]J.De Brito,Abrasion resistance of concrete made with recycled aggregates,Int.J.Sustainable Eng.3(2010)58-64.
[3]W.She,Y.Du,C.W.Miao,J.P.Liu,G.T.Zhao,J.Y.Jiang,Y.S.Zhang,Application of organic-and nanoparticle-modifified foams in foamed concrete:Reinforcement and stabilization mechanisms,Cement Concrete Comp.106(2018)12-22.
[4]W.W.Guo,J.J.Liu,P.Zhang,L.Song,X.Wang,Y.Hu,Multi-functional hydroxyapatite/polyvinyl alcohol composite aerogels with selfcleaning,superior fire resistance and low thermal conductivity,Compos.Sci.Technol.158(2018)128-136.
[5]R.Baetens,B.P.Jelle,A.Gustavsen,Aerogel insulation for building applications:a state-of-the-art review,Energy Build.43(2011)761-769.S.L.Xu,J.H.Liu,Q.Zeng,Towards better characterizing thermal conductivity of cement-based materials:The effects of interfacial thermal resistance and inclusion size,Mater.Design,157(2018)105-118.
[6]A.Kan,R.Demirboga.A novel material for lightweight concrete production.Cem.Concr.Compos.31(2009)489-495.
[7]K.E.Parmenter,F.Milstein,Mechanical properties of silica aerogels,J.Non-Cryst.Solids 223(1998)179-189.
[8]K.A.D.Obrey,K.V.Wilson,D.A.Loy,Enhancing mechanical properties of silica
[9]aerogels,J.Non-Cryst.Solids 357(2011)3435-3441.
[10]T.Yang,H.J.Zhu,Z.H.Zhang,X.Gao,C.S.Zhang,Q.S.Wu,Effect of fly ash microsphere on the rheology and microstructure of alkaliactivated fly ash/slag pastes,Cement Concrete Res.109(2018)198-207.
[11]J.Kim,B.Kim,C.Anand,A.Mano,J.S.M.Zaidi,K.Ariga,J.You,A.Vinu,E.Kim,A Single-Step Synthesis of Electroactive Mesoporous Prodot-Silica Structures.Angew.Chem.-Int.Ed.54(2015)8407-8410.