Effect of fly ash on the rheological properties of potassium magnesium phosphate cement paste
To ensure that the potassium magnesium phosphate cement (MKPC) paste is both easily pourable and compact when repairing narrow cracks, the paste must be capable of self-compacting. Herein, the effects of fly ash (FA) on the workability, rheological properties, and early strength of the MKPC paste we...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-12-01
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| Series: | Case Studies in Construction Materials |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214509522007823 |
| _version_ | 1828335888364470272 |
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| author | Tao Li XiaoHui Xu Jianming Yang Xiamin Hu Jingjing Xue Yulong He Yunjie Tang |
| author_facet | Tao Li XiaoHui Xu Jianming Yang Xiamin Hu Jingjing Xue Yulong He Yunjie Tang |
| author_sort | Tao Li |
| collection | DOAJ |
| description | To ensure that the potassium magnesium phosphate cement (MKPC) paste is both easily pourable and compact when repairing narrow cracks, the paste must be capable of self-compacting. Herein, the effects of fly ash (FA) on the workability, rheological properties, and early strength of the MKPC paste were tested, and the physical phase composition and microstructure of the paste were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results suggested that the working properties of the resulting MKPC paste satisfy the index requirements of the European Design Code for Self-Compacting Concrete of European Federation of National Associations Representing for Concrete when 10 % and 20 % FA are used instead of magnesium oxide powder. The early plastic viscosity of the slurry mixed with 10 % and 20 % (M1, M2) increased by 0.114 and 0.174 Pa s, respectively, in relation to that of the MKPC paste without FA (M0). This result indicated that the FA admixture increases the plastic viscosity of the MKPC paste because FA can promote the early hydration of the MKPC paste and consume more free water. The static yield stress of M2 pastes blended with 20 % FA and the thixotropic ring area decreased by 31.89 Pa and 971.12 Pa s−1, respectively, in relation to those of M0. The addition of an appropriate amount of FA reduces the early static yield stress and improves the thixotropy of the MKPC pastes owing to the dispersing effect of spherical particles in FA and the tumbling effect. Owing to heterogeneous core-forming, active, and microaggregate effects of FA, the structure of the hydrated 1 d M2 sample was significantly denser than that of M0, which subsequently improved the 1 d strength of the hardened body. |
| first_indexed | 2024-04-13T21:52:49Z |
| format | Article |
| id | doaj.art-61431d5d4fd240c08b64fabbb8bafd31 |
| institution | Directory Open Access Journal |
| issn | 2214-5095 |
| language | English |
| last_indexed | 2024-04-13T21:52:49Z |
| publishDate | 2022-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Case Studies in Construction Materials |
| spelling | doaj.art-61431d5d4fd240c08b64fabbb8bafd312022-12-22T02:28:21ZengElsevierCase Studies in Construction Materials2214-50952022-12-0117e01650Effect of fly ash on the rheological properties of potassium magnesium phosphate cement pasteTao Li0XiaoHui Xu1Jianming Yang2Xiamin Hu3Jingjing Xue4Yulong He5Yunjie Tang6School of Civil Engineering, San Jiang University, Nanjing 210012, ChinaChina Construction Eighth Bureau Third Construction Co. Ltd., Nanjing 210012, ChinaSchool of Civil Engineering, San Jiang University, Nanjing 210012, China; Corresponding author.School of Civil Engineering, San Jiang University, Nanjing 210012, ChinaSchool of Civil Engineering, San Jiang University, Nanjing 210012, ChinaSchool of Civil Engineering, San Jiang University, Nanjing 210012, ChinaJiangsu Testing Center for Quality of Construction Engineering Co. Ltd., Nanjing 210012, ChinaTo ensure that the potassium magnesium phosphate cement (MKPC) paste is both easily pourable and compact when repairing narrow cracks, the paste must be capable of self-compacting. Herein, the effects of fly ash (FA) on the workability, rheological properties, and early strength of the MKPC paste were tested, and the physical phase composition and microstructure of the paste were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results suggested that the working properties of the resulting MKPC paste satisfy the index requirements of the European Design Code for Self-Compacting Concrete of European Federation of National Associations Representing for Concrete when 10 % and 20 % FA are used instead of magnesium oxide powder. The early plastic viscosity of the slurry mixed with 10 % and 20 % (M1, M2) increased by 0.114 and 0.174 Pa s, respectively, in relation to that of the MKPC paste without FA (M0). This result indicated that the FA admixture increases the plastic viscosity of the MKPC paste because FA can promote the early hydration of the MKPC paste and consume more free water. The static yield stress of M2 pastes blended with 20 % FA and the thixotropic ring area decreased by 31.89 Pa and 971.12 Pa s−1, respectively, in relation to those of M0. The addition of an appropriate amount of FA reduces the early static yield stress and improves the thixotropy of the MKPC pastes owing to the dispersing effect of spherical particles in FA and the tumbling effect. Owing to heterogeneous core-forming, active, and microaggregate effects of FA, the structure of the hydrated 1 d M2 sample was significantly denser than that of M0, which subsequently improved the 1 d strength of the hardened body.http://www.sciencedirect.com/science/article/pii/S2214509522007823MKPC pasteFly ashPlastic viscosityYield stressStrength |
| spellingShingle | Tao Li XiaoHui Xu Jianming Yang Xiamin Hu Jingjing Xue Yulong He Yunjie Tang Effect of fly ash on the rheological properties of potassium magnesium phosphate cement paste Case Studies in Construction Materials MKPC paste Fly ash Plastic viscosity Yield stress Strength |
| title | Effect of fly ash on the rheological properties of potassium magnesium phosphate cement paste |
| title_full | Effect of fly ash on the rheological properties of potassium magnesium phosphate cement paste |
| title_fullStr | Effect of fly ash on the rheological properties of potassium magnesium phosphate cement paste |
| title_full_unstemmed | Effect of fly ash on the rheological properties of potassium magnesium phosphate cement paste |
| title_short | Effect of fly ash on the rheological properties of potassium magnesium phosphate cement paste |
| title_sort | effect of fly ash on the rheological properties of potassium magnesium phosphate cement paste |
| topic | MKPC paste Fly ash Plastic viscosity Yield stress Strength |
| url | http://www.sciencedirect.com/science/article/pii/S2214509522007823 |
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