Details
| Original language | English |
|---|---|
| Article number | 105977 |
| Journal | Cement and concrete research |
| Volume | 130 |
| Early online date | 24 Jan 2020 |
| Publication status | Published - Apr 2020 |
Abstract
An open question in predicting the rheological properties of cement suspensions has been whether changes of rheology during hydration are merely a result of shifts in the electrostatic interaction patterns of the particles over time, or whether and to which extent steric bridging by hydration products occurs. The latter could explain phenomena such as thixotropy. In this context, parallel investigations using both rheological tests and isothermal calorimetry, 1H NMR relaxometry, conductance and small-angle X-ray scattering (SAXS) measurments were carried out. It could be shown that as early as approx. 2.5 h after water addition at approx. 30 °C, small amounts of Calcium Silicate Hydrate (C-S-H) form which may contribute to a bridging of the cement particles. This phase is followed by rapid C-S-H formation, leading to a non-linear increase in paste stiffness. This phase ends with percolation, i.e. the paste stiffness increases dramatically, simultaneously with the formation of gel pore like structures, which could be observed using NMR.
Keywords
- Hydration, Microstructure, Opus Fluidum Futurum, Rheology, Small-angle X-ray scattering
ASJC Scopus subject areas
- Materials Science(all)
- General Materials Science
- Engineering(all)
- Building and Construction
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In: Cement and concrete research, Vol. 130, 105977, 04.2020.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Early hydration and microstructure formation of Portland cement paste studied by oscillation rheology, isothermal calorimetry, 1H NMR relaxometry, conductance and SAXS
AU - Bogner, A.
AU - Link, J.
AU - Baum, M.
AU - Mahlbacher, M.
AU - Gil-Diaz, T.
AU - Lützenkirchen, J.
AU - Sowoidnich, T.
AU - Heberling, F.
AU - Schäfer, T.
AU - Ludwig, H.-M.
AU - Dehn, F.
AU - Müller, H.S.
AU - Haist, M.
N1 - Funding Information: The funding of Deutsche Forschungsgemeinschaft provided to Michael Haist, Thorsten Schäfer and Michael Ludwig under the grants HA 7917/3-1 , SCHA 1854/4-1 and LU 1652/32-1 is gratefully acknowledged. Harald Müller gratefully acknowledges the funding of 1 Deutsche Forschungsgemeinschaft for the SAXS instrument under the grant INST 121384/71-1 FUGG . Harald Müller and Michael Haist gratefully acknowledge the funding of the Helmholtz Association within the Programme EMR for support in the SAXS measurements. The authors further thank Wittekind Hugo Miesbach Söhne KG for providing the cement.
PY - 2020/4
Y1 - 2020/4
N2 - An open question in predicting the rheological properties of cement suspensions has been whether changes of rheology during hydration are merely a result of shifts in the electrostatic interaction patterns of the particles over time, or whether and to which extent steric bridging by hydration products occurs. The latter could explain phenomena such as thixotropy. In this context, parallel investigations using both rheological tests and isothermal calorimetry, 1H NMR relaxometry, conductance and small-angle X-ray scattering (SAXS) measurments were carried out. It could be shown that as early as approx. 2.5 h after water addition at approx. 30 °C, small amounts of Calcium Silicate Hydrate (C-S-H) form which may contribute to a bridging of the cement particles. This phase is followed by rapid C-S-H formation, leading to a non-linear increase in paste stiffness. This phase ends with percolation, i.e. the paste stiffness increases dramatically, simultaneously with the formation of gel pore like structures, which could be observed using NMR.
AB - An open question in predicting the rheological properties of cement suspensions has been whether changes of rheology during hydration are merely a result of shifts in the electrostatic interaction patterns of the particles over time, or whether and to which extent steric bridging by hydration products occurs. The latter could explain phenomena such as thixotropy. In this context, parallel investigations using both rheological tests and isothermal calorimetry, 1H NMR relaxometry, conductance and small-angle X-ray scattering (SAXS) measurments were carried out. It could be shown that as early as approx. 2.5 h after water addition at approx. 30 °C, small amounts of Calcium Silicate Hydrate (C-S-H) form which may contribute to a bridging of the cement particles. This phase is followed by rapid C-S-H formation, leading to a non-linear increase in paste stiffness. This phase ends with percolation, i.e. the paste stiffness increases dramatically, simultaneously with the formation of gel pore like structures, which could be observed using NMR.
KW - Hydration
KW - Microstructure
KW - Opus Fluidum Futurum
KW - Rheology
KW - Small-angle X-ray scattering
UR - http://www.scopus.com/inward/record.url?scp=85078180010&partnerID=8YFLogxK
U2 - 10.1016/j.cemconres.2020.105977
DO - 10.1016/j.cemconres.2020.105977
M3 - Article
VL - 130
JO - Cement and concrete research
JF - Cement and concrete research
SN - 0008-8846
M1 - 105977
ER -