FEATURES OF CHARACTERISTIC MICROSTRUCTURE AND THEIR EFFECTS ON RESTRAINED AUTOGENOUS SHRINKAGE BEHAVIOR IN HIGH STRENGTH CONCRETES AT EARLY AGES

低水結合材比の高強度コンクリートの内部組織の形成過程を蛍光顕微鏡観察および走査型電子顕微鏡観察により明らかにし, その特徴と自己収縮拘束特性の関係を考察した. 自己収縮拘束特性の試験方法としては, 独自に作製したコンピューター制御式一軸引張型拘束収縮試験装置を使用し, 拘束応力の発現およびクリープによる応力緩和の定量的な評価を行った. 密封養生された高強度コンクリートは, 若材齢においてはその内部組織は全体的に多孔質であり, さらに局所的により多孔質な領域が存在する. 若材齢においては, シリカフュームコンクリートは普通コンクリートよりも単位引張クリープは大きく, これはCSHゲル量の増大とセメントゲル中のハドリー粒子の存在と関連すると推定される.

[1]  F De Larrard,et al.  On the long–term strength losses of silica–fume high–strength concretes , 1991 .

[2]  E. Tazawa,et al.  INFLUENCE OF CONSTITUENTS AND COMPOSITION ON AUTOGENOUS SHRINKAGE OF CEMENTITIOUS MATERIALS , 1997 .

[3]  K. Kjellsen,et al.  Pore structure of cement silica fume systems Presence of hollow-shell pores 1 1 This paper was origi , 1999 .

[4]  Benoît Bissonnette,et al.  Equipment for the analysis of the behaviour of concrete under restrained shrinkage at early ages , 2000 .

[5]  M. Buil,et al.  Effect of Fiber Addition on the Autogenous Shrinkage of Silica Fume , 1989 .

[6]  Odd E. Gjørv,et al.  Effect of silica fume on pore structure and chloride diffusivity of low parosity cement pastes , 1991 .

[7]  P. Freiesleben Hansen,et al.  AUTOGENOUS DEFORMATION AND CHANGE OF THE RELATIVE HUMIDITY IN SILICA FUME-MODIFIED CEMENT PASTE , 1996 .

[8]  L. J. Parrott,et al.  Analysis of Phases in Cement Paste using Backscattered Electron Images, Methanol Adsorption and Thermogravimetric Analysis , 1986 .

[9]  K. Kohno,et al.  Effects of artificial lightweight aggregate on autogenous shrinkage of concrete , 1999 .

[10]  Konstantin Kovler,et al.  Testing system for determining the mechanical behaviour of early age concrete under restrained and free uniaxial shrinkage , 1994 .

[11]  Will Hansen,et al.  Early age creep and stress relaxation of concrete containing blended cements , 2002 .

[12]  Arnon Bentur,et al.  Tensile creep behavior of high strength concretes at early ages , 1999 .

[13]  J. F. Young,et al.  The hydration of tricalcium silicate in the presence of colloidal silica , 1984 .

[14]  M. Pigeon,et al.  Tensile creep at early ages of ordinary, silica fume and fiber reinforced concretes , 1995 .