Abstract
Hydration behavior of cements with additives is complicated due to the multifarious nature of hydration products formed at various stages of hydration. Neutron-based scattering techniques are useful in detecting both the microstructural evolution and water dynamics of hydrating cement pastes. This work investigates the effect of early-age hydration on microstructural evolution of cement paste with local volcanic ash using neutron-based beamline techniques. Early-age hydration dynamics of Portland cement paste with volcanic ash was examined via inelastic neutron scattering (INS), while the evolution of microstructure was observed with small angle neutron scattering (SANS). The data obtained from the ratio of volume fractal to surface fractal clearly showed that greater than 30% substitution of volcanic ash leads to unreacted volcanic ash and coarser morphology, which could influence the chemo-mechanical properties of the resulting hydration products. INS results showed that the effect of finer-particle-sized volcanic ash contributes to initiation of gelation, which accommodates higher conversion of free water to bound water. The multi-scale analysis that combines a time-resolved study of water dynamics along with microstructure is found to provide a basis for effectively utilizing engineered additives for the local cement industry.
| Original language | English |
|---|---|
| Article number | 118175 |
| Journal | Construction and Building Materials |
| Volume | 243 |
| DOIs | |
| State | Published - May 20 2020 |
Funding
A portion of this research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory . We acknowledge the support of the National Institute of Standards and Technology , U.S. Department of Commerce, in providing the neutron research facilities used in this work. We thank Dr. Terrence J. Udovic from National Institute of Standards and Technology (NIST) for helping us to collect Inelastic Neutron Scattering data using BT-4 Filter-Analyzer Neutron Spectrometer (FANS). The authors thank the “Kuwait Foundation for the Advancement of Sciences (KFAS)” for their support during this work. We also acknowledge fruitful discussion with Dr. Andrew Allen from the Materials Structure and Data Group in the Materials Measurement Science Division at NIST. A portion of this research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. We acknowledge the support of the National Institute of Standards and Technology, U.S. Department of Commerce, in providing the neutron research facilities used in this work. We thank Dr. Terrence J. Udovic from National Institute of Standards and Technology (NIST) for helping us to collect Inelastic Neutron Scattering data using BT-4 Filter-Analyzer Neutron Spectrometer (FANS). The authors thank the ?Kuwait Foundation for the Advancement of Sciences (KFAS)? for their support during this work. We also acknowledge fruitful discussion with Dr. Andrew Allen from the Materials Structure and Data Group in the Materials Measurement Science Division at NIST. Certain commercial equipment, instruments, or materials are identified in this paper to foster understanding. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the materials or equipment identified is necessarily the best available for the purpose.
| Funders | Funder number |
|---|---|
| National Institute of Standards and Technology | |
| U.S. Department of Commerce | |
| Office of Science | |
| Oak Ridge National Laboratory | |
| Kuwait Foundation for the Advancement of Sciences | |
| Korea Foundation for Advanced Studies |
Keywords
- Inelastic neutron scattering (INS)
- Microstructure
- Small angle neutron scattering (SANS)
- Volcanic ash
- Volcanic ash