Distribution of porosity surrounding a microfiber in cement paste
This study investigates the microstructural changes of cement paste due to the inclusion of polymeric microfiber at different water-to-cement (w/c) ratios. A procedure to quantify the porosity of epoxy impregnated interfacial transition zone (ITZ) is also presented. Results show that the microstruct...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2024
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/174185 |
| _version_ | 1826122038181363712 |
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| author | He, Shan Chen, Yu Liang, Minfei Yang, En-Hua Schlangen, Erik |
| author2 | School of Civil and Environmental Engineering |
| author_facet | School of Civil and Environmental Engineering He, Shan Chen, Yu Liang, Minfei Yang, En-Hua Schlangen, Erik |
| author_sort | He, Shan |
| collection | NTU |
| description | This study investigates the microstructural changes of cement paste due to the inclusion of polymeric microfiber at different water-to-cement (w/c) ratios. A procedure to quantify the porosity of epoxy impregnated interfacial transition zone (ITZ) is also presented. Results show that the microstructures of the ITZ beneath and above a microfiber, with respect to the gravity direction, are largely different. Though the ITZ at both sides of the fiber are more porous than the bulk matrix, the porosity of the lower ITZ (i.e., the ITZ beneath a fiber) is significantly higher than the upper side (i.e., the ITZ above a fiber). This difference can be attributed to the combined effects of fiber on the initial packing of surrounding cement grains and on the settlement of the fresh mixture. The porosity gradients of the upper ITZs are found to be nearly identical for all the tested w/c ratios, while the porosity gradients of the lower ITZs become steeper when the w/c is higher. The lower side is also found to be the preferred location for the precipitation of calcium hydroxide crystals. Results of energy-dispersive X-ray spectroscopy (EDS) and nano-indentation analyses confirm that the chemical and mechanical properties of the ITZ are also asymmetric. |
| first_indexed | 2024-10-01T05:41:58Z |
| format | Journal Article |
| id | ntu-10356/174185 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T05:41:58Z |
| publishDate | 2024 |
| record_format | dspace |
| spelling | ntu-10356/1741852024-03-22T15:33:34Z Distribution of porosity surrounding a microfiber in cement paste He, Shan Chen, Yu Liang, Minfei Yang, En-Hua Schlangen, Erik School of Civil and Environmental Engineering Engineering Microstructure Fiber reinforcement This study investigates the microstructural changes of cement paste due to the inclusion of polymeric microfiber at different water-to-cement (w/c) ratios. A procedure to quantify the porosity of epoxy impregnated interfacial transition zone (ITZ) is also presented. Results show that the microstructures of the ITZ beneath and above a microfiber, with respect to the gravity direction, are largely different. Though the ITZ at both sides of the fiber are more porous than the bulk matrix, the porosity of the lower ITZ (i.e., the ITZ beneath a fiber) is significantly higher than the upper side (i.e., the ITZ above a fiber). This difference can be attributed to the combined effects of fiber on the initial packing of surrounding cement grains and on the settlement of the fresh mixture. The porosity gradients of the upper ITZs are found to be nearly identical for all the tested w/c ratios, while the porosity gradients of the lower ITZs become steeper when the w/c is higher. The lower side is also found to be the preferred location for the precipitation of calcium hydroxide crystals. Results of energy-dispersive X-ray spectroscopy (EDS) and nano-indentation analyses confirm that the chemical and mechanical properties of the ITZ are also asymmetric. Published version Shan He acknowledges the financial support from the MSCA-ITN project SMARTINCS. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 860006. Minfei Liang would like to acknowledge the funding supported by China Scholarship Council under grant number 202007000027. 2024-03-19T02:25:00Z 2024-03-19T02:25:00Z 2023 Journal Article He, S., Chen, Y., Liang, M., Yang, E. & Schlangen, E. (2023). Distribution of porosity surrounding a microfiber in cement paste. Cement and Concrete Composites, 142, 105188-. https://dx.doi.org/10.1016/j.cemconcomp.2023.105188 0958-9465 https://hdl.handle.net/10356/174185 10.1016/j.cemconcomp.2023.105188 2-s2.0-85163222758 142 105188 en Cement and Concrete Composites © 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). application/pdf |
| spellingShingle | Engineering Microstructure Fiber reinforcement He, Shan Chen, Yu Liang, Minfei Yang, En-Hua Schlangen, Erik Distribution of porosity surrounding a microfiber in cement paste |
| title | Distribution of porosity surrounding a microfiber in cement paste |
| title_full | Distribution of porosity surrounding a microfiber in cement paste |
| title_fullStr | Distribution of porosity surrounding a microfiber in cement paste |
| title_full_unstemmed | Distribution of porosity surrounding a microfiber in cement paste |
| title_short | Distribution of porosity surrounding a microfiber in cement paste |
| title_sort | distribution of porosity surrounding a microfiber in cement paste |
| topic | Engineering Microstructure Fiber reinforcement |
| url | https://hdl.handle.net/10356/174185 |
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