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hydration mechanism of a cementitious material prepared with Si-Mn slag

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International Journal of Minerals,Metallurgy and Materials 2011年第2期18卷 234-239页

作者： Xu-fang Zhang Wen Ni Jun-yu Wu Li-ping Zhu Key Laboratory of the Minstry of Education of China for High-Efficient Mining and Safety of Metal Mines Ministry of Education University of Science and Technology Beijing Beijing 100083 China North China University of Water Resources and Electric Power Zhengzhou 450011 China Beijing Dongfangjianyu Institute of Concrete Science and Technology Beijing 100190 China

A cementitious material was prepared by mixing 80wt% Si-Mn slag powder, 10wt% lime, and 10wt% anhydrite. The compressive strength of mortar samples reaches 51.48 MPa after 28 d curing. The analyses of X-ray diffraction （XRD） and scanning electron microscopy （SEM） show that much ettringite is formed in the sample cured for 3 d, and C-S-H gel increases rapidly during subsequent curing. Nuclear magnetic resonance （NMR） analysis of 29Si and 27Al and infrared spectroscopy （IR） analysis show that aluminum decomposition from tetrahedral network of the slag glass and its subsequent migration and re-combination play an important role in the process of hydration and strength development of the samples.

关键词： slag cement mechanical properties nuclear magnetic resonance (NMR) hydration

hydration properties and thermal analysis of cement-based materials containing limestone powder

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Journal of Central South University 2017年第12期24卷 2932-2939页

作者： ZHOU Wei LI Liang LIU Shu-hua LIU Xing-hong State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China School of Water Resources and Hydropower Engineering Wuhan University Wuhan 430072 China School of Civil Engineering The University of Queensland Brisbane 4072 Australia School of Civil Engineering and Architecture Wuhan University Wuhan 430072 China

The hydration and thermal properties of cement-based materials containing various proportions of limestone powder as a partial replacement for ordinary Portland cement, were investigated and reported. Both compressive and flexural strengths of cement mortar with various contents of limestone powder were tested to study the influence of limestone powder on the strength development of resulting mixtures. The hydration heat and its rate of evolution were also tested, which clearly showed that the replacement percentage of limestone powder had significant effects on the total hydration heat but only a modest influence on the rate of heat evolution of cement-limestone binder. Importantly, the reduction coefficient of limestone powder on the hydration heat, needed for estimation of adiabatic temperature rise of cement-limestone binder, was found to be approximately 0.51. Fundamental thermal properties of these concrete mixtures containing limestone powder were also studied. Increasing the percentage of limestone powder resulted in a significant reduction in the adiabatic temperature rise but only a slight increase in other thermal properties such as thermal conductivity, thermal diffusivity and specific heat. In addition, thermal analysis using finite-element modelling indicated that inclusion of limestone powder did not significantly affect the rate of temperature rise nor the occurrence time of the highest temperature at early ages.

关键词： limestone powder cement mortar hydration properties thermal properties

hydration Characteristics and Mechanical Properties of Cement-Based Materials Modified by Calcined Zeolite and Montmorillonite

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Journal of Renewable Materials 2023年第5期11卷 2191-2207页

作者： Lingling Qin Mengya Zhou Jiahao Yan Ping Duan Yingcan Zhu Wei Chen Zuhua Zhang Aiguo Wang Faculty of Materials Science and Chemistry Key Laboratory of Geological Survey and Evaluation of Ministry of EducationChina University of GeosciencesWuhan430074China Key Laboratory of Advanced Building Materials of Anhui Province Anhui Jianzhu UniversityHefei230022China Guangxi Key Laboratory of New Energy and Building Energy Saving Guilin University of TechnologyGuilin541004China Key Laboratory of Road Structure and Materials of Ministry of Transport Chang’an UniversityXi’an710064China Centre for Sustainable Agricultural Systems University of Southern QueenslandToowoombaQLD4350Australia State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan430070China Key Laboratory for Green&Advanced Civil EngineeringMaterials and Application Technology of Hunan Province College of Civil EngineeringHunan UniversityChangsha410082China

Montmorillonite and clinoptilolite zeolite were used as representative materials to prepare calcined clay-cement binary cementitious materials in order to study the effect of calcination treatment on the activation of clay minerals and the activity difference between layered and framed clays in this *** influence of different calcined clay content(2%,4%,6%,8%,10%)on the fluidity,compressive strength,microstructure,phase change,and hydration heat of cement-based materials were *** calcined clay improves the fluidity of cement-based materials as compared with the uncalcined *** addition of calcined montmorillonite(CMT)improves the development of mechanical strength,and the optimal compressive strength reaches 85 MPa at 28 days with 8%***,the activity of calcined clinoptilolite zeolite(CZL)is weak with few reaction sites,which slightly reduced the mechanical strength as compared to the blank *** addition of CMT changes the microscopic morphology of hydration products such as C-S-H and C-A-H,leading to the formation and transformation of ettringite in the early *** promotes the gradual polymerization of Si-O bonds into Si-O-Si bonds simultaneously,which accelerates the early hydration ***,CZL acts mainly as a filling function in the cementitious *** brief,CMT as an admixture can improve the mechanical properties of cement,but CZL has little *** work provides a guideline for the applications of calcined clay in cement,considering the influence of clay type on workability and mechanical strength.

关键词： Calcined clay cement montmorillonite clinoptilolite zeolite mechanical strength hydration

hydration evolution of pre-cast concrete with steam and water curing

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Journal of Central South University 2013年第10期20卷 2870-2878页

作者：巴明芳钱春香 Faculty of Architectural Civil Engineering and Environment Ningbo University School of Materials Science and Engineering Southeast University

The hydration characteristics of pre-cast concrete considering the effects of effective initial steam-curing and water-curing duration were measured and analyzed with XRD, TG, X-ray CT, SEM-BSE and MIP techniques. The results show that the effective initial steam-curing duration for pre-cast concrete with lower water-binder ratio was 10 14 h at 50 °C and the initial water-curing duration was 7 14 d. And the hydration evolution of cement, fly ash and slag in pre-cast concrete was obtained respectively by combining the hydrochlorides and EDTA selecting dissolution methods, based on which the contents of hydrated and anhydrate in concrete were calculated and the corresponding dynamic capillary porosity was also determined. Moreover, the comparison between calculated results and experimental ones indicates that the proposed evolution models of microscopic characteristics corresponding to hydration kinetics of cemented materials could be adopted to predict the developing trend of capillary porosity and hydration-products content in pre-cast concrete with fly ash and slag under certain curing conditions.

关键词： microstructure evolution hydration kinetics effective curing condition pre-cast concrete

hydration Characteristics and Humidity Control Performance of Calcium Silicate Board Prepared from Mine Tailing and Diatomite

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Journal of Wuhan University of Technology(Materials Science) 2020年第1期35卷 147-154页

作者：战佳宇 YANG Feihua LI Wanmin LIU Xiao WANG Linjun FANG Guiming State Key Laboratory of Solid Waste Reuse for Building Materials Beijing Building Materials Academy of Science ResearchBeijing 100041China College of Materials Science and Engineering Beijing University of TechnologyBeijing 100124China Hebei Ruisuo Research Institute of Solid Waste Engineering Technology Chengde 067000China

The feasibility of utilizing molybdenum tailing and diatomite as siliceous materials to prepare calcium silicate board was *** influences of molybdenum tailing/diatomite proportion on hydration characteristics,thermal conductivity,water absorption,flexural strength and moisture adsorption-desorption property of calcium silicate board were investigated in *** experimental results reveal that molybdenum tailing is environmentally friendly to prepare building *** main hydration products in calcium silicate board under autoclaved condition are C-S-H with low crystallinity and *** tailing is favorable to the formation of *** flexural strength and bulk density of the calcium silicate board gradually increase when the content of molybdenum tailing *** C-S-H is formed with the increase of diatomite content during autoclaved curing process,resulting in the enhancement of moisture adsorptiondesorption performance and the reduction of thermal *** optimal content of molybdenum tailing is 20%,furthermore,the flexual strength and thermal conductivity of calcium silicate board at this content meet the Chinese standard JC/T564.1-2008.

关键词： calcium silicate board molybdenum tailing diatomite hydration humidity control performance

hydration Kinetics of Municipal Solid Wastes Incineration(MSWI) Fly Ash-Cement

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Journal of Wuhan University of Technology(Materials Science) 2019年第3期34卷 596-603页

作者： KAN Lili ZHANG Li SHI Huisheng School of Environment and Architecture University of Shanghai for Science and TechnologyShanghai200093China Key Laboratory of Advanced Civil Engineering Materials of Education Ministry Tongji UniversityShanghai200092China

hydration heat behavior and kinetics of blended cement containing up to 20% MSWI fly ash were investigated based on its hydration heat evolution rate measured by isothermal calorimeter. Kinetics parameters, N and K, and hydration degree, Ca(OH)2 content, were also calculated and analyzed. According to the experimental results, the induction period was elongated, the second heat evolution peak was in advance, and the third hydration heat peak could be detected due to MSWI fly ash pozzolanic reaction. The hydration reaction rate was controlled by nucleation kinetics in the acceleration period and then by diffusion in the decay period, but in the deceleration period, the hydration experienced a dual controlling reaction of autocatalytic chemical reaction and diffusion. The hydration rate of blended cement was faster. Ca(OH)2 content increased before 14 days.

关键词： municipal solid waste incineration (MSWI) fly ash hydration heat kinetics hydration degree

hydration-Enhanced Lubricating Electrospun Nanofibrous Membranes Prevent Tissue Adhesion

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Research 2020年第1期2020卷 812-823页

作者： Liang Cheng Yi Wang Guoming Sun Shizhu Wen Lianfu Deng Hongyu Zhang Wenguo Cui Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases Shanghai Institute of Traumatology and OrthopaedicsRuijin HospitalShanghai Jiao Tong University School of Medicine197 Ruijin 2nd RoadShanghai 200025China State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China College of Chemistry and Environmental Science Hebei UniversityBaoding 071002China Affiliated Hospital of Hebei University Baoding 071000China

Lubrication is the key to efficient function of human tissues and has significant impact on the comfort ***,the construction of a lubricating nanofibrous membrane has not been reported as yet,especially using a one-step surface modification ***,bioinspired by the superlubrication mechanism of articular cartilage,we successfully construct hydration-enhanced lubricating nanofibers via one-step in situ grafting of a copolymer synthesized by dopamine methacrylamide(DMA)and 2-methacryloyloxyethyl phosphorylcholine(MPC)onto electrospun polycaprolactone(PCL)*** zwitterionic MPC structure provides the nanofiber surface with hydration lubrication *** coefficient of friction(COF)of the lubricating nanofibrous membrane decreases significantly and is approximately 65%less than that of pure PCL nanofibers,which are easily worn out under friction regardless of *** lubricating nanofibers,however,show favorable wear-resistance ***,they possess a strong antiadhesion ability of fibroblasts compared with pure PCL *** cell density decreases approximately 9-fold,and the cell area decreases approximately 12 times on day ***,the in vivo antitendon adhesion data reveals that the lubricating nanofiber group has a significantly lower adhesion score and a better antitissue ***,our developed hydration-enhanced lubricating nanofibers show promising applications in the biomedical field such as antiadhesive membranes.

关键词： fibers hydration friction

hydration of Activated Anhydrate Phosphogypsum

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Journal of Wuhan University of Technology(Materials Science) 2013年第3期28卷 535-537页

作者：杨敏 QIAN Jueshi PAN Ling YANG Chengjun College of Chemistry and Chemical Engineering Guizhou University College of Materials Science and Engineering Chongqing University

Phosphogypsum（PG） calcined at 500 ℃ was activated by K2SO4 and salt lime with loose structure as seed crystal. To determine the effect of activation, hydration of the anhydrate PG activated was investigated by examination of the setting time, the proportion of hydrated anhydrate PG, the microstructure of the hardenite and the resistance to water. Results show that activated anhydrate PG hydrates much more rapidly than that in the absence of activators. The activated anhydrate PG has proper setting time and hydrated proportion. The resistance to water was greatly improved. SEM photos show that the set activated PG has hydrated products of rod-like and closely connected crystals. The different addition of activator leads to different compact structure.

关键词： hydration anhydrate phosphogypsum activation K2S04 seed crystal

hydration Characteristics of Sodium Sulfate Slag Cement System

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Journal of Wuhan University of Technology(Materials Science) 2001年第4期16卷 45-47,61页

作者：陈友治 Wuhan Univ Technol Coll Mat Sci & Technol Wuhan 430070 Peoples R China Chongqing Jianzhu Univ Chongqing Peoples R China

The hydration characteristics by thermal analysis (DTA) were determined, and an isothermal calorimeter (IC) was used to study the pastes. The experimental results indicate: (1) The main hydration products of SSC are C-S-H (I) gel with a low Ca/Si ratio, crystalline Thomsonite-type and AFt-type phases containing certain alkali cations; (2) No phases of the AFm-type and high alkaline Ca (OH)(2) in SSC system could benefit the hydrated cements to improve its strength and durability; (3) Crystalline Thomsonite-type and AFt-type phases containing Na+ will greatly reduce free alkali and alleviate the harmness of alkali aggregate reaction (AAR) in SSC system; (4) Similar to ordinary Portland cement (OPC), the hydration process of SSC could be classified into five stage: initial, induction, acceleration, deceleration and decay; (5) Regardless of the activator used, the apparent activation energy is higher with the increased slag in cement system, and the rising temperature could promote the hydration of SSC.

关键词： sodium sulfate slag cement (SSC) hydration alkali cation crysta pline phase heat evolution apparent activation energy