Abstract
Understanding the role of retarder on the chemical nature and molecular architecture of hydrating cement paste is essential for engineering oil well cements with additives. Here, synchrotron X-ray and total neutron scattering with pair distribution function (PDF) analysis were performed in combination with calorimetry and nuclear magnetic resonance (NMR) to examine the retarder effect in hydrating tri-calcium silicate (C3S) and Class G oil well cement paste. Primarily, the retarder, Diethylenetriamine pentamethylene phosphonic acid (DTPMP) influenced the hydration by affecting the Ca-O and Ca-Si pair correlation providing evidence of calcium playing a predominant role in the retardation process. Secondary effects related to Calcium-Silicate-Hydrate (C-S-H) nuclei poisoning influencing the suppression of calcium hydroxide precipitation were observed. These findings provide insights into the retardation mechanism of hydrating cement paste influenced by calcium depletion when subjected to phosphonate retarders.
| Original language | English |
|---|---|
| Article number | 105920 |
| Journal | Cement and Concrete Research |
| Volume | 126 |
| DOIs | |
| State | Published - Dec 2019 |
Funding
Use of the Advanced Photon Source (APS), an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357. A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. We thank Dr. Karena Chapman from Argonne National Laboratory for assisting us with the X-ray PDF experiment. We also express thanks to Dr. Caitlin Quinn from University of Delaware for performing the NMR experiments that were reported in this study. We acknowledge the grant support from Aramco Services Company (ASC), Houston, TX. Finally, we would like to especially thank Dr. Ashraf Al-Tahini, Director of ASC for his encouragement and support during this work. Use of the Advanced Photon Source (APS), an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357 . A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. We thank Dr. Karena Chapman from Argonne National Laboratory for assisting us with the X-ray PDF experiment. We also express thanks to Dr. Caitlin Quinn from University of Delaware for performing the NMR experiments that were reported in this study. We acknowledge the grant support from Aramco Services Company (ASC), Houston, TX. Finally, we would like to especially thank Dr. Ashraf Al-Tahini, Director of ASC for his encouragement and support during this work.
Keywords
- Isothermal calorimetry
- NMR
- Oil well cement
- Pair distribution function (PDF)
- Retarders
- Tri-calcium silicates