Details

Autor(en) / Beteiligte

• Moradian, Masoud
• Hu, Qinang
• Aboustait, Mohammed
• Ley, M. Tyler
• Hanan, Jay C.
• Xiao, Xianghui
• Scherer, George W.
• Zhang, Zhidong

Titel

Direct observation of void evolution during cement hydration

Ist Teil von

• Materials & design, 2017-12, Vol.136 (C), p.137-149

Ort / Verlag

United States: Elsevier Ltd

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• This paper follows the hydration of both portland cement and tricalcium silicate pastes between 30min and 16h of hydration. In-situ fast X-ray computed tomography (fCT) was used to make direct observations of the air-filled void formation in w/s of 0.40 to 0.70 with a micron resolution. The results show that over the first hour of the acceleration period the volume of air-filled voids reaches a maximum value and then decreases during the acceleration period and stays constant. The void distribution changes from a few coarse voids to a large number of smaller and more uniformly distributed voids. This behavior is suggested to be controlled by changes in the ionic strength that cause exsolution of dissolved air from the pore solution. [Display omitted] •A novel in-situ technique is used for direct observation of air-filled space formation in cement paste microstructure.•Air-filled voids are observed to increase in volume and then decrease and stay constant.•The void size distribution changes from a few coarse voids to a large number of small and uniformly distributed voids.•It is suggested that the air-filled void changes are caused by exsolution.