The Experts below are selected from a list of 993 Experts worldwide ranked by ideXlab platform
Ma Jianli - One of the best experts on this subject based on the ideXlab platform.
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effect of Magnesium Oxychloride cement on stabilization solidification of sewage sludge
Construction and Building Materials, 2010Co-Authors: Ma Jianli, Zhao Youcai, Wang Jinmei, Wang LiAbstract:Abstract Solidification/stabilization (S/S) is considered to be a well-established disposal technique to reduce sludge handling and disposal obstacles. In this work, the sewage sludge was solidified at variable proportions with Magnesium Oxychloride cement (denoted as MOC thereinafter) as reagent. The mortar prism samples of 40 × 40 × 160 mm in dimension were prepared and hardened for 24 h at room temperature. Unconfined compressive strength after 10-day curing time, initial and final setting time, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and toxicity leachability of the samples, were used to characterize the macroscopic and microscopic effects caused by the solidified products on the MOC hydration process. The results revealed that the Magnesium hydration of phase 3, phase 5 and other hydration components in CS developed a crystallizing network in the hydrated solidified products, which not only enhanced the strength of CS but also prevented the precipitation of heavy metal ions from CS.
Zongjin Li - One of the best experts on this subject based on the ideXlab platform.
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Influence of fly ash on the properties of Magnesium Oxychloride Cement
Measuring Monitoring and Modeling Concrete Properties, 2020Co-Authors: J. Chan, Zongjin LiAbstract:The effects of fly ash on the properties of Magnesium Oxychloride Cement (MOC) have been studied. The experimental results indicated that the addition of fly ash changes flow property, setting times, compressive strength development, water resistance, volume stability and microstructures of MOC. It might be due to the change of dissolution rate of Magnesium oxide and chemical reaction between MOC and fly ash. MOC containing a certain amount of fly ash has a potential to be utilized in the construction industry
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micromechanical investigation of Magnesium Oxychloride cement paste
Construction and Building Materials, 2016Co-Authors: Chuanlin Hu, Biwan Xu, Binmeng Chen, Zongjin LiAbstract:Abstract In this study, nanoindentation coupled with scanning electron microscopy technique for the microstructural and micromechanical characterizations were applied on the Magnesium Oxychloride (MOC) cement paste. For the first time, micromechanical properties of the reaction product, phase 5 ( 5 Mg ( OH ) 2 · MgCl 2 · 8 H 2 O ) in MOC cement system were investigated. It was determined that the average indentation modulus and hardness of phase 5 were 32.5 ± 4.2 GPa and 1.03 ± 0.19 GPa, respectively. Moreover, the elastic modulus of the MOC cement paste at micro- and macro-scales were further correlated, which built a framework for predicting its macroscopic elastic modulus.
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influence of curing regimes on mechanical properties of Magnesium Oxychloride cement based composites
Construction and Building Materials, 2016Co-Authors: Biwan Xu, Chuanlin Hu, Shuqing Yang, Zongjin LiAbstract:Abstract Influence of the curing regimes that involved different temperatures on mechanical properties of Magnesium Oxychloride (MOC) cement-based composites was investigated. It shows that introduction of the high temperature curing at 75 °C can lead to significant improvements on compressive strengths of these MOC cement-based composites that had ambient curing at the early age. However, introduction of the high temperature curing has clear detrimental effect on water resistance performance of the composites. The high temperature curing induced micro-characteristic changes in the MOC cement-based composites account for the clear macro-mechanical variations.
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Light-weight wood-Magnesium Oxychloride cement composite building products made by extrusion
Construction and Building Materials, 2012Co-Authors: Xiangming Zhou, Zongjin LiAbstract:Magnesium Oxychloride (MOC) cement is a type of non-hydraulic cement with yellowish color in nature and low alkalinity exhibiting many other properties superior to Portland Cement (PC). In this study, light-weight wood-MOC cement composite building products, with sawdust and/or perlite as aggregate, were made through extrusion. Physical, nailing and mechanical properties of these composites were investigated. It was found that the specific dry densities of the wood-MOC cement composites were close to 1.0 and they were nailable like hard natural wood. Their flexural strength decreased as temperature increased. By replacing 50% sawdust in weight by perlite, the composite exhibited less die swell and better performance in resisting high temperature. © 2011 Elsevier Ltd. All rights reserved.
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Recent Development of Magnesium-Based Cements - Magnesium Phosphate Cement and Magnesium Oxychloride Cement
Advances in Science and Technology, 2010Co-Authors: Zongjin Li, Fei Qiao, Chungkong ChauAbstract:The recent development of two types of environmental friendly cementitious materials, Magnesium Oxychloride cement and Magnesium phosphate cement, at HKUST are presented. Both of them can develop high strength without heat treatment under elevated temperature, i.e. the bonding of these cementitious materials can be achieved at low temperature through chemical reaction, as opposed to fusion or sintering at high temperature. The preparation process of the two cements can not only save a lot of energy but also emit no carbon dioxide. For Magnesium Oxychloride cement, our research includes parametric study of the formulation, strength development, water resistance, and also identification of phase composition in the cement paste. Magnesium phosphate cement is mainly applied as rapid repair material in civil engineering. In this paper, the formulation, mechanical properties and performance in patch repair of mortar specimen including strength, bond ability to old concrete substrate, volume stability are studied.
Wang Li - One of the best experts on this subject based on the ideXlab platform.
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effect of Magnesium Oxychloride cement on stabilization solidification of sewage sludge
Construction and Building Materials, 2010Co-Authors: Ma Jianli, Zhao Youcai, Wang Jinmei, Wang LiAbstract:Abstract Solidification/stabilization (S/S) is considered to be a well-established disposal technique to reduce sludge handling and disposal obstacles. In this work, the sewage sludge was solidified at variable proportions with Magnesium Oxychloride cement (denoted as MOC thereinafter) as reagent. The mortar prism samples of 40 × 40 × 160 mm in dimension were prepared and hardened for 24 h at room temperature. Unconfined compressive strength after 10-day curing time, initial and final setting time, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and toxicity leachability of the samples, were used to characterize the macroscopic and microscopic effects caused by the solidified products on the MOC hydration process. The results revealed that the Magnesium hydration of phase 3, phase 5 and other hydration components in CS developed a crystallizing network in the hydrated solidified products, which not only enhanced the strength of CS but also prevented the precipitation of heavy metal ions from CS.
Hong Fa Yu - One of the best experts on this subject based on the ideXlab platform.
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Influence of MgCl2 Solution Concentration on Strength of Magnesium Oxychloride Cement Concrete
Advanced Materials Research, 2020Co-Authors: Hong Xia Qiao, Hong Fa Yu, Ming Ru Zhou, Jian FengAbstract:The molar ratio of MgO and MgCl2 affects prominently on the strength of Magnesium Oxychloride Cement Concrete. Different ratios were used to explore the optimum mixture proportion with the highest uniaxial compressive strength. The influence of the MgCl2 solution concentration is presented. XRD (X-ray diffraction) and SEM (scanning electron microscope) was used to analyze the micro-mechanism.
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influence of fly ash on Magnesium Oxychloride cement deformation
Materials Science Forum, 2015Co-Authors: Jin Mei Dong, Hong Fa Yu, Mei Juan WangAbstract:The inhibition effect of fly ash on the deformation of Magnesium Oxychloride cement is not obvious. With the increase of fly ash, the deformation of Magnesium Oxychloride cement decreased at first, and then increased. The smallest deformation is the proportion of FA-35. The fly ash can promote the formation of the 5·1·8 phase crystal and slow the speed of 5·1·8 phase changing into Mg (OH)2. The growing crystals were disordered, like the scattered tree branches. The causes of FA-35 specimen expansion deformation can be explained by the configuration of the crystal.
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influence of materials ratio on the hydration process of Magnesium Oxychloride cement
Materials Science Forum, 2015Co-Authors: Hong Fa Yu, Xueying Xiao, Jin Mei DongAbstract:Magnesium Oxychloride cement (MOC) has the characteristics of big heat and heat concentration in the hydration process. During the hydration process there is an adverse effect on the formation of hydration products and strength as well as volume stability. The hydration heat method was used to study the hydration process of MOC and analyze the influence of materials ratio on the hydration process in the present investigation. The results show that the hydration process could be divided into five stages, inclding initial stage, induction stage, acceleration stage, retardation stage and stable stage. It has been found that with the increasing of the molar ratio of MgO/MgCl2, the induction stage and acceleration stage extended, and heat release ratio and total heat of 3 days were reduced. With the increasing of the molar ratio of H2O/MgCl2, the induction stage is cut down, acceleration stage is in advance and heat release ratio first rising and then down, and the total heat of 3 days are reduced. It may be concluded that the influence of ratio on the hydration process of MOC is mastered, providing the bases to further improve the properties of Magnesium Oxychloride cement products.
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the effects of alumina leached coal fly ash residue on Magnesium Oxychloride cement
Advances in Cement Research, 2013Co-Authors: Chengyou Wu, Huifang Zhang, Hong Fa YuAbstract:Effects of alumina-leached coal fly ash residue (ACFAR) on Magnesium Oxychloride (MOC) cement are comprehensively investigated. The results show that the addition of ACFAR delayed the setting time of MOC paste. The compressive strength, the flexural strength and the water resistance of MOC are improved by the incorporation of ACFAR. Furthermore, the improvement effects of ACFAR are compared with those of raw coal fly ash (RFA) on MOC cement. Scanning electron microscopy analysis of MOC cement reveals that ACFAR decreases the interspaces in MOC cement and facilitates the radial growth of 5Mg(OH)2·MgCl2·8H2O. X-ray diffraction analysis of MOC cement with ACFAR indicates that the addition of ACFAR promotes the production of Magnesium silicate, which can improve the compactness of 5Mg(OH)2·MgCl2·8H2O and the water resistance of MOC cement.
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compressive strength of fly ash Magnesium Oxychloride cement containing granite wastes
Construction and Building Materials, 2013Co-Authors: Ying Li, Hong Fa Yu, Lina Zheng, Chengyou WuAbstract:Abstract This paper presents the results of an experimental investigation on compressive strength of granite waste fly ash Magnesium Oxychloride cement (GFMOC). Various GFMOC specimens were prepared with 23°Be or 25°Be brine and different proportions of granite fragment (GF) or granite sludge (GS) ranging from 0% (for the control mixture) to 40% of magnesia weight. Compression tests were conducted at the age of 3, 7, and 28 days. The hydration products and paste microstructure were analyzed by XRD and SEM, respectively. The results demonstrated that the water absorption and filling role of the fine particles of granite waste in GFMOC slurry are favorable for 5 Mg(OH)2⋅MgCl2⋅8H2O (P5) and dense microstructure, respectively. The quantity ratio of P5 to Mg(OH)2 (MH) and microstructure are important factors responsible for the compressive strength of GFMOC. The incorporation of granite wastes as aggregate can increase the compressive strength of fly ash Magnesium Oxychloride cement (FMOC).
Yanzhen Yu - One of the best experts on this subject based on the ideXlab platform.
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the influence of compound additive on Magnesium Oxychloride cement urban refuse floor tile
Construction and Building Materials, 2008Co-Authors: Jianquan Li, Guozhong Li, Yanzhen YuAbstract:Abstract The Magnesium Oxychloride cement floor tile was produced by using Magnesium Oxychloride cement and urban refuse. In order to improve the physical performances of the Magnesium Oxychloride cement floor tile, phosphate, stearic acid–styrene acrylic acids copolymer emulsion were adopted. It was educed that the compound additive could reduce the water-absorption and warp distortion, improve intenerating coefficient, and greatly ameliorate the degree on Magnesium salt out of Magnesium Oxychloride cement floor tile. Phosphate can react with Magnesium and produce difficult dissolving complicated hydrated products and gels, which can fill the capillaries, decrease the contact probability between inner structure substances and exterior water, and it improves the water-resistance of the product consumedly. The hydrophobic groups of the copolymer emulsion can penetrate into pores and capillaries of Magnesium cement partially and arrange directionally, which compacts the structure, improves surface characteristics of pores and enhances the water-resistance.
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The influence of compound additive on Magnesium Oxychloride cement/urban refuse floor tile
Construction and Building Materials, 2008Co-Authors: Jianquan Li, Guozhong Li, Yanzhen YuAbstract:Abstract The Magnesium Oxychloride cement floor tile was produced by using Magnesium Oxychloride cement and urban refuse. In order to improve the physical performances of the Magnesium Oxychloride cement floor tile, phosphate, stearic acid–styrene acrylic acids copolymer emulsion were adopted. It was educed that the compound additive could reduce the water-absorption and warp distortion, improve intenerating coefficient, and greatly ameliorate the degree on Magnesium salt out of Magnesium Oxychloride cement floor tile. Phosphate can react with Magnesium and produce difficult dissolving complicated hydrated products and gels, which can fill the capillaries, decrease the contact probability between inner structure substances and exterior water, and it improves the water-resistance of the product consumedly. The hydrophobic groups of the copolymer emulsion can penetrate into pores and capillaries of Magnesium cement partially and arrange directionally, which compacts the structure, improves surface characteristics of pores and enhances the water-resistance.
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experimental study on urban refuse Magnesium Oxychloride cement compound floor tile
Cement and Concrete Research, 2003Co-Authors: Guozhong Li, Yanzhen Yu, Jianquan Li, Yingzi WangAbstract:This article is a study on the production technology of urban refuse Magnesium Oxychloride cement compound floor tile by taking urban refuse and Magnesium Oxychloride cement as main raw materials. We experimentally studied the influence of the concentration of Magnesium chloride solution and the fineness of Magnesium Oxychloride cement on the property of the product by means of experiments and analyzed the microstructure of hydration product using SEM.
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Experimental study on urban refuse/Magnesium Oxychloride cement compound floor tile
Cement and Concrete Research, 2003Co-Authors: Guozhong Li, Yanzhen Yu, Jianquan Li, Yingzi WangAbstract:This article is a study on the production technology of urban refuse Magnesium Oxychloride cement compound floor tile by taking urban refuse and Magnesium Oxychloride cement as main raw materials. We experimentally studied the influence of the concentration of Magnesium chloride solution and the fineness of Magnesium Oxychloride cement on the property of the product by means of experiments and analyzed the microstructure of hydration product using SEM.
