Moisture Transport of Axial-Compression-Damaged Mortar and Concrete in Atmospheric Environment
The moisture transport of axial-compression-damaged mortar and concrete was experimentally and analytically studied in this paper. Five stress levels, i.e., 25%, 40%, 55%, 70%, and 85%, of the corresponding ultimate compressive strengths were selected for mortar and concrete specimens with the water...
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MDPI AG
2022-08-01
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| Online Access: | https://www.mdpi.com/1996-1944/15/16/5498 |
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| author | Yong Zhou Weiping Zhang Fei Tong Xianglin Gu |
| author_facet | Yong Zhou Weiping Zhang Fei Tong Xianglin Gu |
| author_sort | Yong Zhou |
| collection | DOAJ |
| description | The moisture transport of axial-compression-damaged mortar and concrete was experimentally and analytically studied in this paper. Five stress levels, i.e., 25%, 40%, 55%, 70%, and 85%, of the corresponding ultimate compressive strengths were selected for mortar and concrete specimens with the water cement ratio (w/c) of 0.5. Porosities and sorptivities of mortar or concrete before and after axial compression were measured and compared. Based on the Lucas–Washburn equation on absorption, the relationship between sorptivity and pore size distribution as well as porosity was established. A damage-representative radius was proposed to simply quantify the variation of pore characteristics of damaged mortar and concrete, and the moisture transport of axial-compression-damaged mortar and concrete could be predicted by summing the contributions to water absorption from the original pore system and the pore-equivalent microcrack system. It is shown that the porosities of mortar and concrete only slightly increase with the damage level, but the sorptivities are sensitive to axial compression damage, i.e., increasing nearly monotonically with the stress level from 0.3326 to 0.3533 mm/min<sup>0.</sup>5 for damaged mortar specimens (w/c = 0.5) and from 0.1970 to 0.2226 mm/min<sup>0.5</sup> for damaged concrete specimens (w/c = 0.5). The increase trend became more apparent for both materials after a threshold of 40–55% of the corresponding ultimate compressive strengths, which is within the service load of structures, indicating that damage should be considered for chloride ions and water transport in concrete in the tidal zone. The predicted moisture diffusivities of damaged mortar and concrete show marginal difference from those of sound materials because the damage-representative radius could be underestimated due to elastic recovery of materials after unloading. |
| first_indexed | 2024-03-09T04:10:30Z |
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| id | doaj.art-3b72a36d4a0f44d5a8f5703293b03ef9 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T04:10:30Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
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| series | Materials |
| spelling | doaj.art-3b72a36d4a0f44d5a8f5703293b03ef92023-12-03T14:00:50ZengMDPI AGMaterials1996-19442022-08-011516549810.3390/ma15165498Moisture Transport of Axial-Compression-Damaged Mortar and Concrete in Atmospheric EnvironmentYong Zhou0Weiping Zhang1Fei Tong2Xianglin Gu3Key Laboratory of Performance Evolution and Control for Engineering Structures of Ministry of Education, Tongji University, 1239 Siping Road, Shanghai 200092, ChinaKey Laboratory of Performance Evolution and Control for Engineering Structures of Ministry of Education, Tongji University, 1239 Siping Road, Shanghai 200092, ChinaDepartment of Structural Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, ChinaKey Laboratory of Performance Evolution and Control for Engineering Structures of Ministry of Education, Tongji University, 1239 Siping Road, Shanghai 200092, ChinaThe moisture transport of axial-compression-damaged mortar and concrete was experimentally and analytically studied in this paper. Five stress levels, i.e., 25%, 40%, 55%, 70%, and 85%, of the corresponding ultimate compressive strengths were selected for mortar and concrete specimens with the water cement ratio (w/c) of 0.5. Porosities and sorptivities of mortar or concrete before and after axial compression were measured and compared. Based on the Lucas–Washburn equation on absorption, the relationship between sorptivity and pore size distribution as well as porosity was established. A damage-representative radius was proposed to simply quantify the variation of pore characteristics of damaged mortar and concrete, and the moisture transport of axial-compression-damaged mortar and concrete could be predicted by summing the contributions to water absorption from the original pore system and the pore-equivalent microcrack system. It is shown that the porosities of mortar and concrete only slightly increase with the damage level, but the sorptivities are sensitive to axial compression damage, i.e., increasing nearly monotonically with the stress level from 0.3326 to 0.3533 mm/min<sup>0.</sup>5 for damaged mortar specimens (w/c = 0.5) and from 0.1970 to 0.2226 mm/min<sup>0.5</sup> for damaged concrete specimens (w/c = 0.5). The increase trend became more apparent for both materials after a threshold of 40–55% of the corresponding ultimate compressive strengths, which is within the service load of structures, indicating that damage should be considered for chloride ions and water transport in concrete in the tidal zone. The predicted moisture diffusivities of damaged mortar and concrete show marginal difference from those of sound materials because the damage-representative radius could be underestimated due to elastic recovery of materials after unloading.https://www.mdpi.com/1996-1944/15/16/5498moisture transportmicrocrackspore size distributiondamage-representative radius |
| spellingShingle | Yong Zhou Weiping Zhang Fei Tong Xianglin Gu Moisture Transport of Axial-Compression-Damaged Mortar and Concrete in Atmospheric Environment Materials moisture transport microcracks pore size distribution damage-representative radius |
| title | Moisture Transport of Axial-Compression-Damaged Mortar and Concrete in Atmospheric Environment |
| title_full | Moisture Transport of Axial-Compression-Damaged Mortar and Concrete in Atmospheric Environment |
| title_fullStr | Moisture Transport of Axial-Compression-Damaged Mortar and Concrete in Atmospheric Environment |
| title_full_unstemmed | Moisture Transport of Axial-Compression-Damaged Mortar and Concrete in Atmospheric Environment |
| title_short | Moisture Transport of Axial-Compression-Damaged Mortar and Concrete in Atmospheric Environment |
| title_sort | moisture transport of axial compression damaged mortar and concrete in atmospheric environment |
| topic | moisture transport microcracks pore size distribution damage-representative radius |
| url | https://www.mdpi.com/1996-1944/15/16/5498 |
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