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Zheng Z, Huang X, Wang N, Wang T, Zhou L, Xu Z, Chen G, Cao W, Hao H. Hydration Mechanism and Its Effect on the Solubility of Aripiprazole. Pharm Res 2024; 41:113-127. [PMID: 37833571 DOI: 10.1007/s11095-023-03618-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 09/29/2023] [Indexed: 10/15/2023]
Abstract
PROPOSE The propose is to investigate the reasons for the insolubility of Form III in water and to explore the mechanism of the hydration process of Form III. METHODS The conformational and cohesive energies of Form III and Form H1 were calculated using Gaussian 16 and Crystal Explorer 17. Gaussian 16 and Multiwfn 3.8 was used to calculate the molecular surface electrostatic potential of Form III and Form H1 and to calculate the energies of the stronger intermolecular interactions in the crystal structure. The behaviors of Form III in water were simulated using Gromacs 2020.6. Finally, the hydration process from Form III to Form H1 was monitored in situ using Raman spectroscopy. RESULTS The conformational energies of Form III and H1 are almost the same. The cohesion energy of Form H1 is much larger than that of Form III because both number of hydrogen bonds and van der Waals interactions are higher in the Form H1. During the simulation, the supercell of APZ form a supramolecular cluster. Several molecules manually dismantled from the cluster spontaneously combine to form new molecular clusters. Both increases in temperature and external energy input accelerate the hydration process. CONCLUSIONS More hydrogen bonds and strong van der Waals interactions in Form H1 lead to a greater stability. The overall decrease in polarity and the strong binding effect on APZ molecule clusters due to intermolecular interactions lead to the water insolubility of Form III. The hydration process from Form III to Form H1 follows a novel, dandelion sowing-like hydration mechanism.
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Affiliation(s)
- Zhixin Zheng
- The National Engineering Research Center of Industrial Crystallization Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Xin Huang
- The National Engineering Research Center of Industrial Crystallization Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China.
- Zhejiang Institute of Tianjin University, Ningbo, Zhejiang, 315201, China.
| | - Na Wang
- The National Engineering Research Center of Industrial Crystallization Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Ting Wang
- The National Engineering Research Center of Industrial Crystallization Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Lina Zhou
- The National Engineering Research Center of Industrial Crystallization Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Zhao Xu
- The National Engineering Research Center of Industrial Crystallization Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Guibin Chen
- Zhejiang Sundoc Pharmaceutical Science and Tech Co., Ltd, Hangzhou, China, 310051, Zhejiang
| | - Wan Cao
- Zhejiang Sundoc Pharmaceutical Science and Tech Co., Ltd, Hangzhou, China, 310051, Zhejiang
| | - Hongxun Hao
- The National Engineering Research Center of Industrial Crystallization Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China.
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Chen X, Wang J, Jiao H, Yang Z, Zheng D, Sun J. Study on Early Hydration Mechanism of Double-Liquid Grouting Material Modified by Composite Early Strength Agent. Materials (Basel) 2023; 16:6475. [PMID: 37834610 PMCID: PMC10573970 DOI: 10.3390/ma16196475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/22/2023] [Accepted: 09/27/2023] [Indexed: 10/15/2023]
Abstract
To achieve an adjustable setting time and significantly improved early strength of a new type of sulphoaluminate cement-based double-liquid grouting material (SACDL), the effects of calcium formate, sodium sulfate, lithium carbonate, and a composite early strength agent on the setting hardening and early hydration behavior of SACDL paste were studied by means of setting time, fluidity, compressive strength, and viscosity tests. The results showed that the adsorption and osmosis of calcium formate, the complex decomposition of sodium sulfate, the precipitation polarization of lithium carbonate and the synergistic action of the composite early strength agent could accelerate the early hydration rate of SACDL, shorten the coagulation time, and improve the early strength of SACDL. The composite effect of 0.8% calcium formate and 0.5% sodium sulfate is the most significant in promoting coagulation and early strength; the initial setting time and final setting time of the slurry were shortened to 5 min and 10 min, respectively; and the 3 h compressive strength was capable of reaching 16.7 MPa, 31% higher than that of the blank group. In addition, X-ray diffraction and SEM morphology observation were used to study the composition of the hydration products and the evolution of the microstructure, which revealed the early hydration mechanism of SACDL under the synergistic effect of the composite early strength agent: (1) The solubility of tricalcium aluminate (C3A) and dihydrate gypsum (CaSO4·2H2O) increased under the low content composite early strength agent condition, which increased the ettringite (AFt) formation rate. HCOO- was able to penetrate the hydration layers of tricalcium silicate (C3S) and dicalcium silicate (C2S), accelerating the dissolution of C3S and C2S and promoting the early hydration of SACDL. (2) Under the condition of a high dosage of the composite early strength agent, the further increase in Ca2+ concentration promoted the crystallization nodules and precipitation of CH and accelerated the formation of calcium silicate hydrate (C-S-H) gel. C-S-H was filled between a large number of rod-like AFt crystals, thus making the structure more dense.
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Affiliation(s)
- Xinming Chen
- Henan Key Laboratory of Underground Engineering and Disaster Prevention and Control, Henan Polytechnic University, Jiaozuo 454150, China; (X.C.); (H.J.); (Z.Y.); (D.Z.); (J.S.)
- College of Civil Engineering, Henan Polytechnic University, Jiaozuo 454150, China
| | - Jie Wang
- Henan Key Laboratory of Underground Engineering and Disaster Prevention and Control, Henan Polytechnic University, Jiaozuo 454150, China; (X.C.); (H.J.); (Z.Y.); (D.Z.); (J.S.)
- College of Civil Engineering, Henan Polytechnic University, Jiaozuo 454150, China
| | - Huazhe Jiao
- Henan Key Laboratory of Underground Engineering and Disaster Prevention and Control, Henan Polytechnic University, Jiaozuo 454150, China; (X.C.); (H.J.); (Z.Y.); (D.Z.); (J.S.)
- College of Civil Engineering, Henan Polytechnic University, Jiaozuo 454150, China
| | - Zhi Yang
- Henan Key Laboratory of Underground Engineering and Disaster Prevention and Control, Henan Polytechnic University, Jiaozuo 454150, China; (X.C.); (H.J.); (Z.Y.); (D.Z.); (J.S.)
- College of Civil Engineering, Henan Polytechnic University, Jiaozuo 454150, China
| | - Diantao Zheng
- Henan Key Laboratory of Underground Engineering and Disaster Prevention and Control, Henan Polytechnic University, Jiaozuo 454150, China; (X.C.); (H.J.); (Z.Y.); (D.Z.); (J.S.)
- College of Civil Engineering, Henan Polytechnic University, Jiaozuo 454150, China
| | - Jinyu Sun
- Henan Key Laboratory of Underground Engineering and Disaster Prevention and Control, Henan Polytechnic University, Jiaozuo 454150, China; (X.C.); (H.J.); (Z.Y.); (D.Z.); (J.S.)
- College of Civil Engineering, Henan Polytechnic University, Jiaozuo 454150, China
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Muhammad A, Thienel KC, Scherb S. Calcined Clays from Nigeria-Properties and Performance of Supplementary Cementitious Materials Suitable for Producing Level 1 Concrete. Materials (Basel) 2023; 16:2684. [PMID: 37048982 PMCID: PMC10096092 DOI: 10.3390/ma16072684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/23/2023] [Accepted: 03/26/2023] [Indexed: 06/19/2023]
Abstract
In this work, four naturally occurring (two kaolinite-rich and two smectite-rich) clay samples were collected from different areas around the Ashaka cement production plant, located in Gombe State, Nigeria and calcined in a laboratory. The mineralogical characterization of the clays was carried out by XRD. The hydration kinetics of the calcined clay-cement systems were monitored by isothermal calorimetry. Workability was determined using the flow table method. The reactivity of the calcined clays was determined from the solubility of Si and Al ions and the strength activity index. All calcined clays studied met the requirements of ASTM C618 for the use of natural pozzolans as a partial replacement for hydraulic cement. The metasmectite clays yielded a higher specific surface area, increased water demand, and less reactive Si and Al ions compared to the metakaolin clays. The two calcined clay groups require the addition of superplasticizer to achieve a workability class similar to the Portland cement mortar system. They can be used to replace Portland cement at replacement levels of up to 45%, in combination with limestone powder to form an LC3 cement, thereby achieving at least a "Level 1" reduction in greenhouse gas emissions.
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Pan Z, Hu S, Zhang C, Zhou T, Hua G, Li Y, Lv X. Mechanical and Hydration Characteristics of Stabilized Gold Mine Tailings Using a Sustainable Industrial Waste-Based Binder. Materials (Basel) 2023; 16:634. [PMID: 36676370 PMCID: PMC9864667 DOI: 10.3390/ma16020634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/27/2022] [Accepted: 12/30/2022] [Indexed: 06/17/2023]
Abstract
Sustainable resource utilization of tailings is a long-term challenge. Therefore, a novel waste-based binder is proposed in this study to stabilize/solidify gold mine tailings (GMTs). This binder is composed of fly ash (FA), ground blast furnace slag (GBFS), and metakaolin (MK) activated with mixed calcium carbide residue (CCR) as well as pure reagent grade chemical, sodium hydroxide (SH, NaOH), and plaster gypsum (PG, CaSO4·2H2O). The mechanical properties and hydration of stabilized tailings with curing period were investigated. Tests included triaxial compression test and nitrogen adsorption to evaluate the strength of the stabilized tailings and microstructure. The results show that the addition of the waste-based binder yields significant improvement in shear strength. Strain softening occurred for all cured samples, and a local shear band can be observed in all failed stabilized samples. Based on the relationship between strength and curing period, it can be speculated that the hydration reaction of the sample ends after around 40 days of curing. A bimodal pore-size distribution was observed in all solidified/stabilized samples. FTIR and 27Al MAS-NMR were used to analyze hydration products. The strength improvement of stabilized tailings was mainly attributed to the formation of ettringite and C-S-H gels after various polymerization reactions. These new hydrates bind tailings particles and fill the pores to form a more stable structure, which supplied superior mechanical properties. This paper can provide a theoretical basis for exploring the application of the industrial waste-based binder to modify the mechanical properties of gold tailings.
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Affiliation(s)
- Zhenkai Pan
- School of Safety Science and Emergency Management, Wuhan University of Technology, Wuhan 430070, China
- State Key Laboratory of Geotechnical Mechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Shaohua Hu
- School of Safety Science and Emergency Management, Wuhan University of Technology, Wuhan 430070, China
| | - Chao Zhang
- State Key Laboratory of Geotechnical Mechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China
- Key Laboratory of Mine Slope Safety Risk Warning and Disaster Prevention and Mitigation, Ministry of Emergency Management, Wuhan 430071, China
| | - Tong Zhou
- Wushan Copper Mine, Jiangxi Copper Corporation Limited, Ruichang 332204, China
| | - Guowei Hua
- School of Safety Science and Emergency Management, Wuhan University of Technology, Wuhan 430070, China
| | - Yuan Li
- State Key Laboratory of Geotechnical Mechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Xiaolin Lv
- Wushan Copper Mine, Jiangxi Copper Corporation Limited, Ruichang 332204, China
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Su H, Luan Y, Ma Q, Hu B, Liu S, Bai Y. Effect of Different Temperatures on the Hydration Kinetics of Urea-Doped Cement Pastes. Materials (Basel) 2022; 15:8343. [PMID: 36499838 PMCID: PMC9739709 DOI: 10.3390/ma15238343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 10/25/2022] [Accepted: 11/19/2022] [Indexed: 06/17/2023]
Abstract
Urea can solve the problem of concrete cracking due to temperature stress. However, its effect is affected by temperature. The influencing mechanism of temperature on urea-doped cement pastes is still unclear. This paper explores the effect of different temperatures on the hydration kinetics of urea-doped cement pastes. The isothermal calorimeter (TAM Air) was used to test hydration at three constant temperatures (20 °C, 40 °C, and 60 °C). The effects of the urea admixture and temperature on the hydration process and hydration kinetics parameters were investigated. The hydration mechanism was analyzed, and the changes in macroscopic mechanical compressive strength and porosity were tested. The results show that, as the urea content (UC) increases, the rate of hydration gradually decreases, and the increase in temperature promotes the inhibitory effect of urea. At 60 °C, UC of 8% can be reduced by 23.5% compared with the pure cement (PC) group's hydration rate. As the temperature increases from 20 °C to 60 °C, the Krstulovic-Dabic model changes from the NG-I-D process to the NG-D process. The effect of urea on the compressive strength of the cement is mainly shown in the early stage, and its effect on later strength is not obvious. In addition, urea will increase its early porosity. The porosity will gradually decrease in the later stage. The results of the study clarify the effect of temperature on urea-doped cement pastes. The optimal content of urea in cement is about 8%, which will provide theoretical guidance for solving the cracking problem of large-volume concrete due to temperature stress.
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Affiliation(s)
- Hui Su
- School of Water Conservancy and Hydroelectric Power, Hebei University of Engineering, Handan 056038, China
- Hebei Provincial Key Laboratory of Intelligent Water Resources, Handan 056038, China
| | - Yawei Luan
- School of Water Conservancy and Hydroelectric Power, Hebei University of Engineering, Handan 056038, China
- Hebei Provincial Key Laboratory of Intelligent Water Resources, Handan 056038, China
| | - Qiujuan Ma
- School of Water Conservancy and Hydroelectric Power, Hebei University of Engineering, Handan 056038, China
- Hebei Provincial Key Laboratory of Intelligent Water Resources, Handan 056038, China
| | - Baowen Hu
- School of Water Conservancy and Hydroelectric Power, Hebei University of Engineering, Handan 056038, China
- Hebei Provincial Key Laboratory of Intelligent Water Resources, Handan 056038, China
| | - Shaoxing Liu
- School of Water Conservancy and Hydroelectric Power, Hebei University of Engineering, Handan 056038, China
- Hebei Provincial Key Laboratory of Intelligent Water Resources, Handan 056038, China
| | - Yanjie Bai
- School of Water Conservancy and Hydroelectric Power, Hebei University of Engineering, Handan 056038, China
- Nanjing Hydraulic Research Institute, State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing 210029, China
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Yang Z, Zhang D, Fang C, Jiao Y, Kang D, Yan C, Zhang J. Hydration Mechanisms of Alkali-Activated Cementitious Materials with Ternary Solid Waste Composition. Materials (Basel) 2022; 15:ma15103616. [PMID: 35629642 PMCID: PMC9143352 DOI: 10.3390/ma15103616] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/12/2022] [Accepted: 05/17/2022] [Indexed: 11/16/2022]
Abstract
Considering the recent eco-friendly and efficient utilization of three kinds of solid waste, including calcium silicate slag (CSS), fly ash (FA), and blast-furnace slag (BFS), alkali-activated cementitious composite materials using these three waste products were prepared with varying content of sodium silicate solution. The hydration mechanisms of the cementitious materials were analyzed by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy. The results show that the composite is a binary cementitious system composed of C(N)-A-S-H and C-S-H. Si and Al minerals in FA and BFS are depolymerized to form the Q0 structure of SiO4 and AlO4. Meanwhile, β-dicalcium silicate in CSS hydrates to form C-S-H and Ca(OH)2. Part of Ca(OH)2 reacts with the Q0 structure of AlO4 and SiO4 to produce lawsonite and wairakite with a low polymerization degree of the Si-O and Al-O bonds. With the participation of Na+, part of Ca(OH)2 reacts with the Q0 structure of AlO4 and the Q3 structure of SiO4, which comes from the sodium silicate solution. When the sodium silicate content is 9.2%, the macro properties of the composites effectively reach saturation. The compressive strength for composites with 9.2% sodium silicate was 23.7 and 35.9 MPa after curing for 7 and 28 days, respectively.
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Affiliation(s)
- Zhijie Yang
- School of Mining and Technology, Inner Mongolia University of Technology, Hohhot 010051, China; (D.Z.); (C.F.); (Y.J.); (D.K.); (C.Y.); (J.Z.)
- The Key Laboratory of Green Development for Mineral Resources, Inner Mongolia University of Technology, Hohhot 010051, China
- Correspondence: ; Tel.: +86-18104711683
| | - De Zhang
- School of Mining and Technology, Inner Mongolia University of Technology, Hohhot 010051, China; (D.Z.); (C.F.); (Y.J.); (D.K.); (C.Y.); (J.Z.)
- The Key Laboratory of Green Development for Mineral Resources, Inner Mongolia University of Technology, Hohhot 010051, China
| | - Chengyang Fang
- School of Mining and Technology, Inner Mongolia University of Technology, Hohhot 010051, China; (D.Z.); (C.F.); (Y.J.); (D.K.); (C.Y.); (J.Z.)
- The Key Laboratory of Green Development for Mineral Resources, Inner Mongolia University of Technology, Hohhot 010051, China
| | - Yang Jiao
- School of Mining and Technology, Inner Mongolia University of Technology, Hohhot 010051, China; (D.Z.); (C.F.); (Y.J.); (D.K.); (C.Y.); (J.Z.)
- The Key Laboratory of Green Development for Mineral Resources, Inner Mongolia University of Technology, Hohhot 010051, China
| | - Dong Kang
- School of Mining and Technology, Inner Mongolia University of Technology, Hohhot 010051, China; (D.Z.); (C.F.); (Y.J.); (D.K.); (C.Y.); (J.Z.)
- The Key Laboratory of Green Development for Mineral Resources, Inner Mongolia University of Technology, Hohhot 010051, China
| | - Changwang Yan
- School of Mining and Technology, Inner Mongolia University of Technology, Hohhot 010051, China; (D.Z.); (C.F.); (Y.J.); (D.K.); (C.Y.); (J.Z.)
- The Key Laboratory of Green Development for Mineral Resources, Inner Mongolia University of Technology, Hohhot 010051, China
| | - Ju Zhang
- School of Mining and Technology, Inner Mongolia University of Technology, Hohhot 010051, China; (D.Z.); (C.F.); (Y.J.); (D.K.); (C.Y.); (J.Z.)
- The Key Laboratory of Green Development for Mineral Resources, Inner Mongolia University of Technology, Hohhot 010051, China
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Xu D, Fu P, Ni W, Wang Q, Li K. Characterization and Hydration Mechanism of Ammonia Soda Residue and Portland Cement Composite Cementitious Material. Materials (Basel) 2021; 14:ma14174794. [PMID: 34500883 PMCID: PMC8432485 DOI: 10.3390/ma14174794] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/18/2021] [Accepted: 08/20/2021] [Indexed: 11/20/2022]
Abstract
The use of ammonia soda residue (ASR) to prepare building materials is an effective way to dispose of ASR on a large scale, but this process suffers from a lack of data and theoretical basis. In this paper, a composite cementitious material was prepared using ASR and cement, and the hydration mechanism of cementitious materials with 5%, 10%, and 20% ASR was studied. The XRD and SEM results showed that the main hydration products of ASR-cement composite cementitious materials were an amorphous C-S-H gel, hexagonal plate-like Ca(OH)2 (CH), and regular hexagonal plate-like Friedel’s salt (FS). The addition of ASR increased the heat of hydration of the cementitious material, which increased upon increasing the ASR content. The addition of ASR also reduced the cumulative pore volume of the hardened paste, which displayed the optimal pore structure when the ASR content was 5%. In addition, ASR shortened the setting time compared with the cement group, and the final setting times of the pastes with 5%, 10%, and 20% ASR were 30 min, 45 min, and 70 min shorter, respectively. When the ASR content did not exceed 10%, the 3-day compressive strength of the mortar was significantly improved, but the 28-day compressive strength was worse. Finally, the hydration mechanism and potential applications of the cementitious material are discussed. The results of this paper promote the use of ASR in building materials to reduce CO2 emissions in the cement industry.
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Affiliation(s)
- Dong Xu
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; (D.X.); (Q.W.)
- Beijing Key Laboratory on Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China
- Key Laboratory of the Ministry of Education of China for High-Efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Beijing 100083, China; (P.F.); (K.L.)
| | - Pingfeng Fu
- Key Laboratory of the Ministry of Education of China for High-Efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Beijing 100083, China; (P.F.); (K.L.)
- School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Wen Ni
- Beijing Key Laboratory on Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China
- Key Laboratory of the Ministry of Education of China for High-Efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Beijing 100083, China; (P.F.); (K.L.)
- School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China
- Correspondence:
| | - Qunhui Wang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; (D.X.); (Q.W.)
- Beijing Key Laboratory on Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China
| | - Keqing Li
- Key Laboratory of the Ministry of Education of China for High-Efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Beijing 100083, China; (P.F.); (K.L.)
- School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China
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Xie L, Deng M, Tang J, Liu K. Hydration and Strength Development of Cementitious Materials Prepared with Phosphorous-Bearing Clinkers. Materials (Basel) 2021; 14:508. [PMID: 33494420 DOI: 10.3390/ma14030508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/11/2021] [Accepted: 01/19/2021] [Indexed: 11/25/2022]
Abstract
To rationally use low-grade phosphorous limestone as the raw materials for cement production, the influence of phosphorous introduced by fluorapatite during the clinker calcination process on the mechanical properties of cementitious materials is investigated. Hydration kinetics, phase evolutions, and microstructure of cement pastes have been studied by using calorimetry, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results indicate that the mechanical properties of cementitious materials can be slightly improved due to the mineralization effect of the small amount of phosphorous in the clinker and significantly decreased with an increase of phosphorous. High content of phosphorous will reduce the content of C3S and make the formation of α′-C2S-xC3P(x: 0–0.05), whose hydration reactivity is rather lower, such that on the one hand less-hydrated products, such as calcium silicate hydrate (C-S-H) gel, can be obtained, and on the other hand, the hydration reaction will be slowed by severely prolonging the induction period. Interestingly, small particles can be observed on the surface of hydration products, but no new phase can be detected by XRD. When the content of P2O5 is 2.0%, the cement can meet the requirements of P·II 42.5 cement in China. Hopefully, this can provide significant guidance for the use of cement prepared by fluorapatite as raw material.
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Xie J, Zhao J, Wang J, Wang C, Huang P, Fang C. Sulfate Resistance of Recycled Aggregate Concrete with GGBS and Fly Ash-Based Geopolymer. Materials (Basel) 2019; 12:ma12081247. [PMID: 31014035 PMCID: PMC6515352 DOI: 10.3390/ma12081247] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 04/04/2019] [Accepted: 04/11/2019] [Indexed: 11/16/2022]
Abstract
There is a constant drive for the development of ultra-high-performance concrete using modern green engineering technologies. These concretes have to exhibit enhanced durability and incorporate energy-saving and environment-friendly functions. The object of this work was to develop a green concrete with an improved sulfate resistance. In this new type of concrete, recycled aggregates from construction and demolition (C&D) waste were used as coarse aggregates, and granulated blast furnace slag (GGBS) and fly ash-based geopolymer were used to totally replace the cement in concrete. This study focused on the sulfate resistance of this geopolymer recycled aggregate concrete (GRAC). A series of measurements including compression, X-ray diffraction (XRD), and scanning electron microscopy (SEM) tests were conducted to investigate the physical properties and hydration mechanisms of the GRAC after different exposure cycles in a sulfate environment. The results indicate that the GRAC with a higher content of GGBS had a lower mass loss and a higher residual compressive strength after the sulfate exposure. The proposed GRACs, showing an excellent sulfate resistance, can be used in construction projects in sulfate environments and hence can reduce the need for cement as well as the disposal of C&D wastes.
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Affiliation(s)
- Jianhe Xie
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, China.
| | - Jianbai Zhao
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, China.
| | - Junjie Wang
- Division of Engineering, NYU Abu Dhabi, P.O. Box 129188, Abu Dhabi, UAE.
| | - Chonghao Wang
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, China.
| | - Peiyan Huang
- School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China.
| | - Chi Fang
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, China.
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