FraMCoS 8 2013 Toledo, Spain

Silica-additivated Cement Pastes obtained from Different Mixing Conditions: Influence on the Hydration Process

Several cement pastes with different addition content and size, nano and micro silica, have been prepared, following two different ways in incorporating the additives. Paste test specimens of dimensions 1x1x6 cmhave been prepared and characterized by TGA, XRD, SEM and…

First page of: Silica-additivated Cement Pastes obtained from Different Mixing Conditions: Influence on the Hydration Process
Year 2013
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Abstract

Several cement pastes with different addition content and size, nano and micro silica, have been prepared, following two different ways in incorporating the additives. Paste test specimens of dimensions 1x1x6 cmhave been prepared and characterized by TGA, XRD, SEM and 29 Si NMR. In order to evaluate the rate of hydration, measurements were performed in samples with different curing ages: 2, 7 and 28 days. The obtained results show a higher degree of hydration for previously additivated samples compared to manual mixing cements with the same curing age. Moreover, relevant changes concerning the structure of hydrated compounds have also been detected. The behavior of previously additivated samples is consistent with the presence of hydrated calcium silicoaluminates. Finally, regardless of the method employed, the addition of nanoparticles modifies the size of the obtained crystals. SEM images show a significant reduction in the size of portlandite crystals.