Effect of Citric Acid-Modified Chitosan on Hydration Regulation and Mechanism of Composite Cementitious Material System
The temperature stress caused by the large temperature difference is the main factor causing harmful cracks in large-volume concrete. The introduction of admixtures is beneficial to reduce the temperature difference inside and outside the large-volume concrete. This study investigated the mechanism...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-12-01
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| Series: | Buildings |
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| Online Access: | https://www.mdpi.com/2075-5309/14/1/41 |
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| author | Liguo Wang Zhibin Qin Jiandong Wu Guangxia Sheng Han Wang Kai Liu Xiaobin Dong Fengjuan Wang Jinyang Jiang |
| author_facet | Liguo Wang Zhibin Qin Jiandong Wu Guangxia Sheng Han Wang Kai Liu Xiaobin Dong Fengjuan Wang Jinyang Jiang |
| author_sort | Liguo Wang |
| collection | DOAJ |
| description | The temperature stress caused by the large temperature difference is the main factor causing harmful cracks in large-volume concrete. The introduction of admixtures is beneficial to reduce the temperature difference inside and outside the large-volume concrete. This study investigated the mechanism of how citric acid-modified chitosan (CAMC) affects the hydration heat release process and hydration products of composite cementitious materials. Through methods such as hydration heat, X-ray diffraction (XRD), mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM), and nuclear magnetic resonance (NMR), the mechanism of how CAMC controls the hydration heat release process and hydration products of composite cementitious materials was revealed. The results show that the addition of CAMC delayed the hydration process of cementitious materials without affecting the type of hydration products but affected the content of each phase of hydration products. As the hydration process proceeded, the total porosity of all samples decreased, the volume of large pores decreased, and the volume of small pores increased. As the content of CAMC increased, the pore diameter of the hardened paste gradually became smaller, the proportion of large pores decreased, and the later hydration microstructure became more dense. The increase in CAMC dosage resulted in a decrease in the peak intensity of Q<sup>2</sup> in the paste, indicating that Al atoms in Q<sup>2</sup> (<sup>1</sup>Al) existed in the form of Alcoordination, which proves that CAMC reduced its hydration degree and delayed cement hydration. |
| first_indexed | 2024-03-08T09:56:40Z |
| format | Article |
| id | doaj.art-32278b0113de46bea80b16f41d0759e7 |
| institution | Directory Open Access Journal |
| issn | 2075-5309 |
| language | English |
| last_indexed | 2024-03-08T09:56:40Z |
| publishDate | 2023-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Buildings |
| spelling | doaj.art-32278b0113de46bea80b16f41d0759e72024-01-29T13:48:22ZengMDPI AGBuildings2075-53092023-12-011414110.3390/buildings14010041Effect of Citric Acid-Modified Chitosan on Hydration Regulation and Mechanism of Composite Cementitious Material SystemLiguo Wang0Zhibin Qin1Jiandong Wu2Guangxia Sheng3Han Wang4Kai Liu5Xiaobin Dong6Fengjuan Wang7Jinyang Jiang8School of Materials Science and Engineering, Southeast University, Nanjing 211189, ChinaSchool of Materials Science and Engineering, Southeast University, Nanjing 211189, ChinaShandong Provincial Communications Planning and Design Institute Group Co., Ltd., Jinan 250101, ChinaSchool of Materials Science and Engineering, Southeast University, Nanjing 211189, ChinaSchool of Materials Science and Engineering, Southeast University, Nanjing 211189, ChinaJiangsu China Construction Ready Mixed Concrete Co., Ltd., NanJing 210033, ChinaSchool of Materials Science and Engineering, Southeast University, Nanjing 211189, ChinaSchool of Materials Science and Engineering, Southeast University, Nanjing 211189, ChinaSchool of Materials Science and Engineering, Southeast University, Nanjing 211189, ChinaThe temperature stress caused by the large temperature difference is the main factor causing harmful cracks in large-volume concrete. The introduction of admixtures is beneficial to reduce the temperature difference inside and outside the large-volume concrete. This study investigated the mechanism of how citric acid-modified chitosan (CAMC) affects the hydration heat release process and hydration products of composite cementitious materials. Through methods such as hydration heat, X-ray diffraction (XRD), mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM), and nuclear magnetic resonance (NMR), the mechanism of how CAMC controls the hydration heat release process and hydration products of composite cementitious materials was revealed. The results show that the addition of CAMC delayed the hydration process of cementitious materials without affecting the type of hydration products but affected the content of each phase of hydration products. As the hydration process proceeded, the total porosity of all samples decreased, the volume of large pores decreased, and the volume of small pores increased. As the content of CAMC increased, the pore diameter of the hardened paste gradually became smaller, the proportion of large pores decreased, and the later hydration microstructure became more dense. The increase in CAMC dosage resulted in a decrease in the peak intensity of Q<sup>2</sup> in the paste, indicating that Al atoms in Q<sup>2</sup> (<sup>1</sup>Al) existed in the form of Alcoordination, which proves that CAMC reduced its hydration degree and delayed cement hydration.https://www.mdpi.com/2075-5309/14/1/41CAMCcomposite cementitious materialshydration exothermic processhydration products |
| spellingShingle | Liguo Wang Zhibin Qin Jiandong Wu Guangxia Sheng Han Wang Kai Liu Xiaobin Dong Fengjuan Wang Jinyang Jiang Effect of Citric Acid-Modified Chitosan on Hydration Regulation and Mechanism of Composite Cementitious Material System Buildings CAMC composite cementitious materials hydration exothermic process hydration products |
| title | Effect of Citric Acid-Modified Chitosan on Hydration Regulation and Mechanism of Composite Cementitious Material System |
| title_full | Effect of Citric Acid-Modified Chitosan on Hydration Regulation and Mechanism of Composite Cementitious Material System |
| title_fullStr | Effect of Citric Acid-Modified Chitosan on Hydration Regulation and Mechanism of Composite Cementitious Material System |
| title_full_unstemmed | Effect of Citric Acid-Modified Chitosan on Hydration Regulation and Mechanism of Composite Cementitious Material System |
| title_short | Effect of Citric Acid-Modified Chitosan on Hydration Regulation and Mechanism of Composite Cementitious Material System |
| title_sort | effect of citric acid modified chitosan on hydration regulation and mechanism of composite cementitious material system |
| topic | CAMC composite cementitious materials hydration exothermic process hydration products |
| url | https://www.mdpi.com/2075-5309/14/1/41 |
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