Cement-Based Materials Modified by Colloidal Nano-Silica: Impermeability Characteristic and Microstructure
Colloidal nano-silica (CNS) was used to improve the mechanical and impermeability characteristics of mortar in this study. The samples were prepared with 0%, 1%, 2% and 3% (solid content) CNS addition. The mechanical strength and permeability of each mixture was studied, and the mechanism behind was...
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| Format: | Article |
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MDPI AG
2022-09-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/12/18/3176 |
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| author | Jie Wang Xuesong Lu Baoguo Ma Hongbo Tan |
| author_facet | Jie Wang Xuesong Lu Baoguo Ma Hongbo Tan |
| author_sort | Jie Wang |
| collection | DOAJ |
| description | Colloidal nano-silica (CNS) was used to improve the mechanical and impermeability characteristics of mortar in this study. The samples were prepared with 0%, 1%, 2% and 3% (solid content) CNS addition. The mechanical strength and permeability of each mixture was studied, and the mechanism behind was revealed by hydration heat evolution, XRD, DSC-DTG, <sup>29</sup>Si MAS-NMR and SEM-EDS analysis. The compressive strength and impermeability characteristics of mortars incorporating CNS were significantly improved. The experimental results demonstrated that the incorporation of CNS promoted the early hydration process of cement, thus increasing the polymerization degree of hydrated calcium silicate, decreasing the porosity, and improving the microstructure of mortar. Furthermore, 3% CNS decreased the Ca/Si ratio of the interfacial transition zone (ITZ) from 3.18 to 2.22, thus the enrichment of CH was reduced and the density and strength were improved. This was mainly because of the high pozzolanic activity of CNS, which consumed plenty of calcium hydroxide and converted to C-S-H. Besides, nanoscale CNS and C-S-H particles filled the voids between hydrates, thus refining the pore size, increasing the complexity of pores, and improving the microstructure of ITZ which contributed to the improvement of the impermeability. |
| first_indexed | 2024-03-09T22:58:06Z |
| format | Article |
| id | doaj.art-65576d8030c6461982dedffa810f7f94 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-09T22:58:06Z |
| publishDate | 2022-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-65576d8030c6461982dedffa810f7f942023-11-23T18:06:46ZengMDPI AGNanomaterials2079-49912022-09-011218317610.3390/nano12183176Cement-Based Materials Modified by Colloidal Nano-Silica: Impermeability Characteristic and MicrostructureJie Wang0Xuesong Lu1Baoguo Ma2Hongbo Tan3School of Architectural Engineering, Huanggang Normal University, Huanggang 438000, ChinaSchool of Architectural Engineering, Huanggang Normal University, Huanggang 438000, ChinaState Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, ChinaSchool of Architectural Engineering, Huanggang Normal University, Huanggang 438000, ChinaColloidal nano-silica (CNS) was used to improve the mechanical and impermeability characteristics of mortar in this study. The samples were prepared with 0%, 1%, 2% and 3% (solid content) CNS addition. The mechanical strength and permeability of each mixture was studied, and the mechanism behind was revealed by hydration heat evolution, XRD, DSC-DTG, <sup>29</sup>Si MAS-NMR and SEM-EDS analysis. The compressive strength and impermeability characteristics of mortars incorporating CNS were significantly improved. The experimental results demonstrated that the incorporation of CNS promoted the early hydration process of cement, thus increasing the polymerization degree of hydrated calcium silicate, decreasing the porosity, and improving the microstructure of mortar. Furthermore, 3% CNS decreased the Ca/Si ratio of the interfacial transition zone (ITZ) from 3.18 to 2.22, thus the enrichment of CH was reduced and the density and strength were improved. This was mainly because of the high pozzolanic activity of CNS, which consumed plenty of calcium hydroxide and converted to C-S-H. Besides, nanoscale CNS and C-S-H particles filled the voids between hydrates, thus refining the pore size, increasing the complexity of pores, and improving the microstructure of ITZ which contributed to the improvement of the impermeability.https://www.mdpi.com/2079-4991/12/18/3176colloidal nano-silicaimpermeabilitymechanical propertiespore structureinterfacial transition zone |
| spellingShingle | Jie Wang Xuesong Lu Baoguo Ma Hongbo Tan Cement-Based Materials Modified by Colloidal Nano-Silica: Impermeability Characteristic and Microstructure Nanomaterials colloidal nano-silica impermeability mechanical properties pore structure interfacial transition zone |
| title | Cement-Based Materials Modified by Colloidal Nano-Silica: Impermeability Characteristic and Microstructure |
| title_full | Cement-Based Materials Modified by Colloidal Nano-Silica: Impermeability Characteristic and Microstructure |
| title_fullStr | Cement-Based Materials Modified by Colloidal Nano-Silica: Impermeability Characteristic and Microstructure |
| title_full_unstemmed | Cement-Based Materials Modified by Colloidal Nano-Silica: Impermeability Characteristic and Microstructure |
| title_short | Cement-Based Materials Modified by Colloidal Nano-Silica: Impermeability Characteristic and Microstructure |
| title_sort | cement based materials modified by colloidal nano silica impermeability characteristic and microstructure |
| topic | colloidal nano-silica impermeability mechanical properties pore structure interfacial transition zone |
| url | https://www.mdpi.com/2079-4991/12/18/3176 |
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