| Autor: |
Bae, Sungchul, Taylor, Rae, Shapiro, David, Denes, Peter, Joseph, John, Celestre, Rich, Marchesini, Stefano, Padmore, Howard, Tyliszczak, Tolek, Warwick, Tony, Kilcoyne, David, Levitz, Pierre, M Monteiro, Paulo J., Struble, L. |
| Předmět: |
|
| Zdroj: |
Journal of the American Ceramic Society; Dec2015, Vol. 98 Issue 12, p4090-4095, 6p |
| Abstrakt: |
Morphological details of calcium silicate hydrate (C-S-H) stemming from the hydration process of Portland cement (PC) phases are crucial for understanding the PC-based systems but are still only partially known. Here we introduce the first soft X-ray ptychographic imaging of tricalcium silicate (C3S) hydration products. The results are compared using both scanning transmission X-ray and electron transmission microscopy data. The evidence shows that ptychography is a powerful method to visualize the details of outer and inner product C-S-H of fully hydrated C3S, which have fibrillar and an interglobular structure with average void sizes of 20 nm, respectively. The high-resolution ptychrography image enables us to perform morphological quantification of C-S-H, and, for the first time, to possibly distinguish the contributions of inner and outer product C-S-H to the small angle scattering of cement paste. The results indicate that the outer product C-S- H is mainly responsible for the q -3 regime, whereas the inner product C-S-H transitions to a q-2 regime. Various hypotheses are discussed to explain these regimes. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
