コンクリートの耐久性には、コンクリートの耐霜性、不浸透性、耐薬品性、鋼の耐食性、耐侵食性が含まれます。耐霜性、不浸透性、耐薬品性に​​ついてのみお話します。侵食効果。
a）耐霜性：シリカパウダーが小さいため、シリカフュームコンクリートの耐霜性は基本的に通常のコンクリートと同じです。シリカ粉末の量が15％を超えると、耐凍害性が低下します。多数のテストを通じて、この見解は基本的に確認されています。主な理由は、シリカフュームが15％を超えると、コンクリートの膨張が増加し、相対的な動的弾性率が低下し、圧縮強度が急激に低下するためです。コンクリートの内部特性の観点から、比表面積が小さく、間隔係数が大きい。
b) Impermeability: Because シリカパウダー particles are small, 20-100 times smaller than cement particles, they can be filled into the voids between cement particles to make concrete compact. At the same time, the secondary hydration of silica powder blocks new products. Permeation channels in concrete, so the impermeability of silica fume concrete is very strong, the permeability of concrete increases with the increase of water-binder ratio, this is because the compactness of water-cement is relatively poorer than that of concrete.
c) Chemical resistance: Mixing シリカパウダー into concrete can reduce the content of Ca (OH) 2 and increase the compactness of concrete. It can effectively improve the corrosion ability of weak acid. However, it cannot be used in strong acid or high-depth weak acid. CSH decomposes in acid. In addition, it is also resistant to salt corrosion, especially to chlorides and sulfates. The reason why it is resistant to salt corrosion is that the silica fume concrete is denser and the pore structure is improved, thereby reducing The transmission speed of harmful ions is reduced and the formation of soluble Ca (OH) 2 and ettringite (3CaO·Al2O3·3CaSO4 ·32H2) is reduced, and the result of increasing hydrated calcium silicate crystals.