Ceramics-Silikáty 56, (4) 389 - 395 (2012) |
|
HYDRATION MECHANISMS OF CALCIUM SULPHOALUMINATE C4A3S̄ , C4AS̄ PHASE AND ACTIVE BELITE β-C2S
|
El-Didamony H. 1, El-Sokkari T. M. 2, Khalil KH. A. 1,
Heikal Mohamed 3,
Ahmed I. A. 3
|
1 Chemistry Department, Faculty of Science, Zagazig University, Zagazig, Egypt
2 Housing and Building Research Centre, Cairo, Egypt
3 Chemistry Department, Faculty of Science, Benha University, Benha, Egypt
|
Keywords: Calcium sulphoaluminate (C4A3S̄), β-dicalsium silicate (active belite), Hydration characteristics, XRD and DSC
|
Highly reactive belite and calcium sulphoaluminate as well as monosulphate mix were prepared from nano-materials at lower
temperatures ~1250oC. The crystal size of these materials was 25, 16 and 27 nm as determined from the X-ray analysis. The
sulphoaluminate belite cement is a recent type of cement prepared at lower temperature with good properties. The aim of the
present work is to synthesize C4A3S̄, monosulphate mix C4AS̄ and active belite β-C2S. The hydration mechanism was studied
by XRD and DSC techniques as well as by the determination of chemically combined water contents of cement pastes with
curing time. The results reveal that ettringite is first formed hydrates in the monosulphate mix, which then converted into
monosulphate hydrates. The results of DSC and XRD are in good agreement with those of combined water contents. On
the other side, the rate of hydration of active belite increases linearly from 3 up to 90 days, whereas, the traditional belite
hydrates increase with lower rate up to 90 days, due to the thermodynamic stability structure of traditional belite. |
 PDF (1.2 MB) |
|
