Effects of nanoscale C-S-H seeds dispersed in PCE on rheological and early mechanical properties of mortar
Calcium silicate hydrate (C-S-H) gel as one of the main hydration products in ordinary Portland cement, which was the main source of strength for cement-based materials. In this paper, the nanoscale C-S-H seeds (Ca/Si=1) were successfully synthesised by hydrothermal reaction and applied to mortar us...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2024-12-01
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| Series: | Case Studies in Construction Materials |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214509524011872 |
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| Summary: | Calcium silicate hydrate (C-S-H) gel as one of the main hydration products in ordinary Portland cement, which was the main source of strength for cement-based materials. In this paper, the nanoscale C-S-H seeds (Ca/Si=1) were successfully synthesised by hydrothermal reaction and applied to mortar using polycarboxylate superplasticiser (PCE) dispersion. The influence of nanoscale C-S-H seeds content on the fluidity, rheological properties, thixotropy, and early mechanical properties of mortars was investigated. Based on the investigation of the zeta potential and organic carbon adsorption capacity of nanoscale C-S-H seeds, the influence of C-S-H seeds content on the hydration heat and microstructure of mortar was analysed. The research results showed the particle size range of nanoscale C-S-H seeds prepared by hydrothermal reaction was between 3.1 nm and 145.6 nm, and they had good dispersibility in mortar with the aid of PCE. With an increase in the content of nanoscale C-S-H seeds, the spreading of the cement mortar showed a slow decreasing trend and its yield stress and viscosity showed a significant increasing trend, indicating a certain degree of thixotropy. The nanoscale C-S-H seeds provided more nucleation sites, promoted early hydration of the pastes, improved the early strength of the mortar and reduced the porosity of the hardened pastes. When the nanoscale C-S-H seeds content of the mortar was 2 %, the early compressive strength and flexural strength of the mortar after 7 days were 19.9 MPa and 5 MPa respectively. |
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| ISSN: | 2214-5095 |