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Wang Z, Sun T, Ouyang G, Li H, Li Z, He J. Role of polyferric sulphate in hydration regulation of phosphogypsum-based excess-sulphate slag cement: A multiscale investigation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:173750. [PMID: 38866154 DOI: 10.1016/j.scitotenv.2024.173750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 05/24/2024] [Accepted: 06/02/2024] [Indexed: 06/14/2024]
Abstract
Current demand for waste recycling, phosphogypsum-based excess-sulphate slag cement (PESSC) as a sustainable cement prepared by solid wastes, urges enhancing its performance development based on microstructure optimisation. For the purpose of improving the performance and durability of PESSC used in normal or corrosive environments, it is deemed an efficient technique to produce iron-doped compounds with high thermodynamic stability. This paper presents a systematic study of the effect of iron modification on PESSC binders by introducing 0%-2% polyferric sulphate (PFS) from a multiscale viewpoint. XPS, 29Si and 27Al NMR, and TEM were used to characterise the nanostructure of solid particles firstly at Level I. Then, the chemical composition and phase assemblage of PESSC binders were revealed at Level II in terms of ICC, ICP, DTG-DSC, FTIR, BSE-EDS and XRD. Finally, setting time and strength development were determined at Level III. Results indicated that the soluble FeOH4- supplied by the hydrolysis of PFS promotes the generation of iron-doped ettringite with a greater length-to-diameter ratio and thermodynamic stability. Seeding effect of iron doping also promotes the production of spherical and retiform gels with a slight influence on the chemical components and polymerisation. Despite the fact that iron doping weakens the early strength of PESSC mortars, it promotes the persistent hydration rate by retarding precipitation and encapsulation of hydrates on the surface of the slag, showing excellent strength in the later stages. In view of microstructure evolution and performance development during each stage, PFS supplementation within 1.0% is considered a feasible modification of PESSC relying on the formation control of iron-doped hydrates.
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Affiliation(s)
- Ziyan Wang
- School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China; State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China
| | - Tao Sun
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China; Wuhan University of Technology Advanced Engineering Technology Research Institute of Zhongshan City, Zhongshan 528437, China; Marine Building Materials and Civil Engineering Centre, Science and Education Innovation Park of Wuhan University of Technology in Sanya, Sanya 572000, China.
| | - Gaoshang Ouyang
- School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China; State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China
| | - Haoyuan Li
- School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China; State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China
| | - Zhiwei Li
- School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China; State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China
| | - Juntu He
- School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China; State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China
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2
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Zhao C, Yu J, Chen X, Wu Q, Zhou W, Bauchy M. Atomistic origin of kinetics in hydrated aluminosilicate gels upon precipitation. J Chem Phys 2023; 159:144501. [PMID: 37811823 DOI: 10.1063/5.0165937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 09/22/2023] [Indexed: 10/10/2023] Open
Abstract
Calcium-alumino-silicate-hydrate (CaO-Al2O3-SiO2-H2O, or C-A-S-H) gel, which is the binding phase of cement-based materials, greatly influences concrete mechanical properties and durability. However, the atomic-scale kinetics of the aluminosilicate network condensation remains puzzling. Here, based on reactive molecular dynamics simulations of C-A-S-H systems formation with varying Al/Ca molar ratios, we study the kinetic mechanism of the hydrated aluminosilicate gels upon precipitation. We show that the condensation activation energy decreases with the Al/Ca molar ratio, which suggests that the concentration of the Al polytopes has a great effect on controlling the kinetics of the gelation reaction. Significantly, we demonstrate that 5-fold Al atoms are mainly forming at high Al/Ca molar ratios since there are insufficient hydrogen cations or extra calcium cations to compensate the negatively charged Al polytopes at high Al/Ca molar ratios during accelerated aging.
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Affiliation(s)
- Cheng Zhao
- School of Civil Engineering and Architecture, Wuhan Institute of Technology, Wuhan 430074, China
- Hubei Provincial Engineering Research Center for Green Civil Engineering Materials and Structures, Wuhan 430074, China
| | - Jiahui Yu
- School of Civil Engineering and Architecture, Wuhan Institute of Technology, Wuhan 430074, China
- Hubei Provincial Engineering Research Center for Green Civil Engineering Materials and Structures, Wuhan 430074, China
| | - Xuyong Chen
- School of Civil Engineering and Architecture, Wuhan Institute of Technology, Wuhan 430074, China
- Hubei Provincial Engineering Research Center for Green Civil Engineering Materials and Structures, Wuhan 430074, China
| | - Qiaoyun Wu
- School of Civil Engineering and Architecture, Wuhan Institute of Technology, Wuhan 430074, China
- Hubei Provincial Engineering Research Center for Green Civil Engineering Materials and Structures, Wuhan 430074, China
| | - Wei Zhou
- State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
| | - Mathieu Bauchy
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
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Schade T, Middendorf B. Prediction Model Based on DoE and FTIR Data to Control Fast Setting and Early Shrinkage of Alkaline-Activated Slag/Silica Fume Blended Cementitious Material. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16114104. [PMID: 37297238 DOI: 10.3390/ma16114104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/28/2023] [Accepted: 05/29/2023] [Indexed: 06/12/2023]
Abstract
This study aims to develop a material-saving performance prediction model for fast-hardening alkali-activated slag/silica fume blended pastes. The hydration process in the early stage and the microstructural properties after 24 h were analyzed using design of experiments (DoE). The experimental results show that the curing time and the FTIR wavenumber of the Si-O-T (T = Al, Si) bond in the band range of 900-1000 cm-1 after 24 h can be predicted accurately. In detailed investigations, low wavenumbers from FTIR analysis were found to correlate with reduced shrinkage. The activator exerts a quadratic and not a silica modulus-related conditioned linear influence on the performance properties. Consequently, the prediction model based on FTIR measurements proved to be suitable in evaluation tests for predicting the material properties of those binders in the building chemistry sector.
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Affiliation(s)
- Tim Schade
- Department of Structural Materials and Construction Chemistry, University of Kassel, Moenchebergstr. 7, 34125 Kassel, Germany
- Deutscher Beton- und Bautechnik-Verein e.V., 10785 Berlin, Germany
| | - Bernhard Middendorf
- Department of Structural Materials and Construction Chemistry, University of Kassel, Moenchebergstr. 7, 34125 Kassel, Germany
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Chen Y, Wu X, Yin W, Tang S, Yan G. Effects of Waste Glass Powder on Rheological and Mechanical Properties of Calcium Carbide Residue Alkali-Activated Composite Cementitious Materials System. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16093590. [PMID: 37176472 PMCID: PMC10179798 DOI: 10.3390/ma16093590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/03/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023]
Abstract
As a municipal solid waste, waste glass undergoes pozzolanic activity when ground to a certain fineness. In this paper, calcium carbide residue (CCR) and Na2CO3 were used as composite alkali activators for a glass powder-based composite cementitious system. A total of 60% fly ash (FA) and 40% ground granulated blast furnace slag (GGBS) were used as the reference group of the composite cementitious material system, and the effects of 5%, 10%, 15%, and 20% glass powder (GP) replacing FA on the rheological behavior, mechanical properties, and microstructure of alkali-activated composite cementitious systems were investigated. The results showed that with the increase in GP replacing FA, the fluidity of the alkali-activated materials gradually decreased, the shear stress and the equivalent plastic viscosity both showed an increasing trend, and the paste gradually changed from shear thinning to shear thickening. Compared with the reference sample, the fluidity of the alkali-activated material paste with a 20% GP replacement of FA was reduced by 15.3%, the yield shear stress was increased by 49.6%, and the equivalent plastic viscosity was elevated by 32.1%. For the 28d alkali-activated material pastes, the compressive strength and flexural strength were increased by 13% and 20.3%, respectively. The microstructure analysis showed the substitution of FA by GP promoted the alkali-activated reaction to a certain extent, and more C-A-S-H gel was formed.
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Affiliation(s)
- Youzhi Chen
- State Key Laboratory of Silicate Materials for Architecture, Wuhan University of Technology, Wuhan 430070, China
| | - Xiuqi Wu
- State Key Laboratory of Silicate Materials for Architecture, Wuhan University of Technology, Wuhan 430070, China
| | - Weisong Yin
- Key Laboratory of Roadway Bridge & Structure Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Shichang Tang
- State Key Laboratory of Silicate Materials for Architecture, Wuhan University of Technology, Wuhan 430070, China
| | - Ge Yan
- Wuhan Hanyang Municipal Construction Group Co., Ltd., Wuhan 430050, China
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Akmalaiuly K, Berdikul N, Pundienė I, Pranckevičienė J. The Effect of Mechanical Activation of Fly Ash on Cement-Based Materials Hydration and Hardened State Properties. MATERIALS (BASEL, SWITZERLAND) 2023; 16:2959. [PMID: 37109794 PMCID: PMC10146790 DOI: 10.3390/ma16082959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 03/28/2023] [Accepted: 04/03/2023] [Indexed: 06/19/2023]
Abstract
Fly ash from coal represents the foremost waste product of fossil fuel combustion. These waste materials are most widely utilised in the cement and concrete industries, but the extent of their use is insufficient. This study investigated the physical, mineralogical, and morphological characteristics of non-treated and mechanically activated fly ash. The possibility of enhancing the hydration rate of the fresh cement paste by replacing part of the cement with non-treated and mechanically activated fly ash, and the hardened cement paste's structure and early compressive strength performance, were evaluated. At the first stage of the study, up to 20% mass of cement was replaced by untreated and mechanically activated fly ash to understand the impact of the mechanical activation on the hydration course; rheological properties, such as spread and setting time; hydration products; mechanical properties; and microstructure of fresh and hardened cement paste. The results show that a higher amount of untreated fly ash significantly prolongs the cement hydration process, decreases hydration temperature, deteriorates the structure and decreases compressive strength. Mechanical activation caused the breakdown of large porous aggregates in fly ash, enhancing the physical properties and reactivity of fly ash particles. Due to increased fineness and pozzolanic activity by up to 15%, mechanically activated fly ash shortens the time of maximum exothermic temperature and increases this temperature by up to 16%. Due to nanosized particles and higher pozzolanic activity, mechanically activated fly ash facilitates a denser structure, improves the contact zone between the cement matrix, and increases compressive strength up to 30%.
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Affiliation(s)
- Kenzhebek Akmalaiuly
- Department of Construction and Building Materials, Satbayev University, Satbayeva Str. 22, 050013 Almaty, Kazakhstan; (K.A.); (N.B.)
| | - Nazerke Berdikul
- Department of Construction and Building Materials, Satbayev University, Satbayeva Str. 22, 050013 Almaty, Kazakhstan; (K.A.); (N.B.)
| | - Ina Pundienė
- Laboratory of Concrete Technology, Institute of Building Materials, Vilnius Gediminas Technical University, Linkmenų Str. 28, LT-08217 Vilnius, Lithuania;
| | - Jolanta Pranckevičienė
- Laboratory of Concrete Technology, Institute of Building Materials, Vilnius Gediminas Technical University, Linkmenų Str. 28, LT-08217 Vilnius, Lithuania;
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Wieland E, Miron GD, Ma B, Geng G, Lothenbach B. Speciation of iron(II/III) at the iron-cement interface: a review. MATERIALS AND STRUCTURES 2023; 56:31. [PMID: 36777453 PMCID: PMC9908688 DOI: 10.1617/s11527-023-02115-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 01/21/2023] [Indexed: 06/18/2023]
Abstract
Steel is used as reinforcement in construction materials and it is also an important component of cement-stabilized waste materials to be disposed of in deep geological repositories for radioactive waste. Steel corrosion releases dissolved Fe(II/III) species that can form corrosion products on the steel surface or interact with cementitious materials at the iron-cement interface. The thermodynamically stable Fe species in the given conditions may diffuse further into the adjacent, porous cement matrix and react with individual cement phases. Thus, the retention of Fe(II/III) by the hydrate assemblage of cement paste is an important process affecting the diffusive transport of the aqueous species into the cementitious materials. The diffusion of aqueous Fe(II/III) species from the steel surface into the adjacent cementitious material coupled with the kinetically controlled formation of iron corrosion products, such as by Fe(II) oxidation, decisively determines the extension of the corrosion front. This review summarises the state-of-the art knowledge on the interaction of ferrous and ferric iron with cement phases based on a literature survey and provides new insights and proper perspectives for future study on interaction systems of iron and cement.
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Affiliation(s)
- Erich Wieland
- Laboratory for Waste Management, Paul Scherrer Institut, Villigen PSI, Switzerland
| | - George Dan Miron
- Laboratory for Waste Management, Paul Scherrer Institut, Villigen PSI, Switzerland
| | - Bin Ma
- Laboratory for Waste Management, Paul Scherrer Institut, Villigen PSI, Switzerland
| | - Guoqing Geng
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, 117576 Singapore
| | - Barbara Lothenbach
- Concrete & Asphalt Laboratory, Empa, Dübendorf, Switzerland
- Institute of Geological Sciences, University of Bern, Bern, Switzerland
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Chen Q, Zhang Q, Wang Y, Zhang Q, Liu Y. Highly-efficient fluoride retention in on-site solidification/stabilization of phosphogypsum: Cemented paste backfill synergizes with poly-aluminum chloride activation. CHEMOSPHERE 2022; 309:136652. [PMID: 36216108 DOI: 10.1016/j.chemosphere.2022.136652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/14/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Phosphogypsum (PG) is a massively generated hazardous by-product in the phosphorus industry. Large-scale, efficient, profitable on-site recycling is an emerging topic for promoting sustainable phosphorus circularity and mitigating potential human exposure. In this work, we integrated a green and low-cost additive polymeric aluminum chloride (PAC) into the binder design of PG immobilization. The overall experimental results illustrate that the incorporation of PAC can efficiently promote the cement hydration reaction, with amorphous phases increased from 25.9 wt% (control group) to 27.5 wt% (with 2 g/L PAC). The macro-investigations indicate that the PAC optimized the porosity and mechanical properties of specimens, facilitating a mechanically stable solidified matrix for extrapolating its field engineering application. The detailed micrographs and elemental mapping demonstrate that apart from co-existing with the hydration products, the PAC agent plays a role in the immobilization of fluoride. Herein, the combined optimization enhanced the fluoride retention capacity due to the precipitated additional hydration products, comparable encapsulation, and high adsorption ability of PAC agents. Therefore our design of PAC-augmented binders can open up a new field of PG on-site solidification/stabilization application that ensures efficient fluoride retention in a technically feasible and financially profitable methodology.
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Affiliation(s)
- Qiusong Chen
- Sinosteel Maanshan General Institute of Mining Research Co., Ltd., Maanshan, 24300, China; School of Resources and Safety Engineering, Central South University, Changsha, 410083, China
| | - Qi Zhang
- School of Resources and Safety Engineering, Central South University, Changsha, 410083, China
| | - Yunmin Wang
- Sinosteel Maanshan General Institute of Mining Research Co., Ltd., Maanshan, 24300, China; School of Resources and Safety Engineering, Central South University, Changsha, 410083, China
| | - Qinli Zhang
- School of Resources and Safety Engineering, Central South University, Changsha, 410083, China
| | - Yikai Liu
- Department of Geosciences, University of Padova, Padova, 35131, Italy.
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8
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Wu Z, Li L, Gao F, Zhang G, Cai J, Cheng X. Resource Utilization of Red Mud from the Solid Waste of Aluminum Industry Used in Geothermal Wells. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8446. [PMID: 36499943 PMCID: PMC9740700 DOI: 10.3390/ma15238446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/25/2022] [Accepted: 11/24/2022] [Indexed: 06/17/2023]
Abstract
It is difficult for the commonly used Class G oil well cement to withstand the high-temperature environment of geothermal wells, and it is easy to deteriorate the mechanical properties and damage the integrity of the cement sheath. Industrial solid waste red mud can be used as supplementary cementing materials (SCMs) to improve its mechanical properties at high temperatures. In addition, compared to Class G oil well cement, high belite cement (HBC) has lower energy consumption and better mechanical properties at high temperatures. In this study, the mechanical properties of HBC as a gel material and quartz sand and red mud as SCMs were studied at high temperatures. The ratio of HBC to SCMs and the ratio of quartz sand to red mud in SCMs were optimized using the response surface method (RSM). The response surface was established using the three-level factorial design model, which fit well with the experimental data. The optimization results show that the best mass ratio of SCMs/HBC is 37.5% and that the best quality ratio of quartz sand/red mud is 9 under the curing conditions of 180 °C. However, the best mass ratio of SCMs/HBC is 49.3%, and the best quality ratio of quartz sand/red mud is 7 under 220 °C. With the addition of SCMs, the silicon-to-calcium ratio of HBC hydration products decreases, and high-temperature-stable xonotlite and tobermorite can be formed. After adding SCMs, the cement sample is denser without obvious cracks.
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Affiliation(s)
- Zhiqiang Wu
- CNOOC Research Institute Co., Ltd., Beijing 100028, China
| | - Lihua Li
- CNPC Bohai Drilling Engineering Co., Ltd., Tianjin 300457, China
| | - Fei Gao
- CNPC Bohai Drilling Engineering Co., Ltd., Tianjin 300457, China
| | - Gaoyin Zhang
- School of New Energy and Materials, Southwest Petroleum University, Chengdu 610500, China
| | - Jingxuan Cai
- School of New Energy and Materials, Southwest Petroleum University, Chengdu 610500, China
| | - Xiaowei Cheng
- School of New Energy and Materials, Southwest Petroleum University, Chengdu 610500, China
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Barzgar S, Yan Y, Tarik M, Skibsted J, Ludwig C, Lothenbach B. A long-term study on structural changes in calcium aluminate silicate hydrates. MATERIALS AND STRUCTURES 2022; 55:243. [PMID: 36447990 PMCID: PMC9700620 DOI: 10.1617/s11527-022-02080-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 11/08/2022] [Indexed: 06/16/2023]
Abstract
UNLABELLED Production of blended cements in which Portland cement is combined with supplementary cementitious materials (SCM) is an effective strategy for reducing the CO2 emissions during cement manufacturing and achieving sustainable concrete production. However, the high Al2O3 and SiO2 contents of SCM change the chemical composition of the main hydration product, calcium aluminate silicate hydrate (C-A-S-H). Herein, spectroscopic and structural data for C-A-S-H gels are reported in a large range of equilibration times from 3 months up to 2 years and Al/Si molar ratios from 0.001 to 0.2. The 27Al MAS NMR spectroscopy and thermogravimetric analysis indicate that in addition to the C-A-S-H phase, secondary phases such as strätlingite, katoite, Al(OH)3 and calcium aluminate hydrate are present at Al/Si ≥ 0.03 limiting the uptake of Al in C-A-S-H. More secondary phases are present at higher Al concentrations; their content decreases with equilibration time while more Al is taken up in the C-A-S-H phase. At low Al contents, Al concentrations decrease strongly with time indicating a slow equilibration, in contrast to high Al contents where a clear change in Al concentrations over time was not observed indicating that the equilibrium has been reached faster. The 27Al NMR studies show that tetrahedrally coordinated Al is incorporated in C-A-S-H and its amount increases with the amount of Al present in the solution. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1617/s11527-022-02080-x.
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Affiliation(s)
- Sonya Barzgar
- Empa, Concrete & Asphalt Laboratory, CH-8610 Dübendorf, Switzerland
- École Polytechnique Fédéral de Lausanne (EPFL), ENAC IIE GR-LUD, CH-1015 Lausanne, Switzerland
- Present Address: Sweco UK, Advisory and Planning Division, EC2M 7LS London, UK
| | - Yiru Yan
- Empa, Concrete & Asphalt Laboratory, CH-8610 Dübendorf, Switzerland
| | - Mohamed Tarik
- Paul Scherrer Institute (PSI), ENE LBK CPM, 5232 Villigen PSI, Switzerland
| | - Jorgen Skibsted
- Aarhus University, Department of Chemistry and Interdisciplinary Nanoscience Center, 8000 Aarhus C, Denmark
| | - Christian Ludwig
- Empa, Concrete & Asphalt Laboratory, CH-8610 Dübendorf, Switzerland
- Paul Scherrer Institute (PSI), ENE LBK CPM, 5232 Villigen PSI, Switzerland
| | - Barbara Lothenbach
- Empa, Concrete & Asphalt Laboratory, CH-8610 Dübendorf, Switzerland
- NTNU, Department of Structural Engineering, Trondheim, Norway
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Phase Analysis of Alkali-Activated Slag Hybridized with Low-Calcium and High-Calcium Fly Ash. SUSTAINABILITY 2022. [DOI: 10.3390/su14073767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This paper investigates the hydrated phase assemblage, microstructure, and gel composition of sodium hydroxide (NaOH)-activated fly ash–slag blends with either low-calcium or high-calcium fly ash. The results show that the nature of precipitated calcium–aluminosilicate–hydrate (C-A-S-H) and alkali aluminosilicate-hydrate (N-A-S-H) depends on the fly ash composition and slag-to-fly ash ratio. However, regardless of fly ash composition and slag-to-fly ash ratio, a universal linear compositional relationship exists between Al/Ca ratio and Si/Ca ratio in precipitated gels. This indicates that there exists a structural limitation on the incorporation of Al3+ for Si4+ in the tetrahedral silicate of C-A-S-H, N-A-S-H, or metastable N-C-A-S-H gels. In a hybrid slag–fly ash system, the framework structure of precipitated gels is an assemblage of aluminosilicate units with heterogeneous Ca2+ and Na+ distribution. The amount and reactivity of calcium and alkalis seem to play a critical role in determining the structure and properties of precipitated gels in hybrid systems. The low cementitious capability in alkali-activated high-calcium fly ash may be attributed to the unstable N-C-A-S-H gel structure with concurrent high Na and Ca contents.
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11
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Characterization of Monochromate and Hemichromate AFm Phases and Chromate-Containing Ettringite by 1H, 27Al, and 53Cr MAS NMR Spectroscopy. MINERALS 2022. [DOI: 10.3390/min12030371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
The calcium aluminate hydrate AFm and AFt phases formed upon hydration of Portland cement have an important role in the stabilization and solidification of hazardous chromate ions in hardened cement. AFm monochromate (Ca4[Al(OH)6]2(CrO4)·12H2O), AFm hemichromate (Ca4[Al(OH)6]2(CrO4)0.5(OH)·12H2O) and the chromate-containing AFt phase, Ca6[Al(OH)6]2-(CrO4)3·24H2O, were synthesized and investigated by 1H, 27Al, and 53Cr MAS NMR spectroscopy. 27Al quadrupolar coupling parameters (CQ, ηQ) and isotropic chemical shifts (δiso) were determined for the three phases, including two distinct Al sites in chromate-AFt, as observed by 27Al MAS and MQMAS NMR. Two dominant peaks are apparent in the 1H MAS NMR spectra of each of the phases. For the AFm phases, these resonances are assigned to framework hydroxyl groups (1.7–2.0 ppm) and water molecules/hydroxyls (5.0–5.5 ppm) in the interlayer. For chromate-AFt, the peaks are ascribed to framework hydroxyl groups in the [Ca6Al2(OH)12]6+ columns (~1.4 ppm) and water molecules (~4.8 ppm) associated with the Ca ions. 53Cr MAS NMR spectra acquired at 22.3 T for the samples show a narrow resonance for both chromate AFm phases, whereas indications of three distinct Cr resonances are apparent for the chromate AFt. The absence of any second-order quadrupolar effects in the 53Cr NMR spectra strongly suggests that the chromate ions are highly mobile in the anionic sites of the AFm and AFt structures. The NMR data reported in this work are in agreement with the reported crystal structures for the chromate AFm and AFt phases and may be useful for identification and characterization of chromate fixation in cementitious systems, complementing information gained from conventional powder X-ray diffraction studies.
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Ramézani H, Jeong J, Bhatia SK, Papadakis VG. Assessment of CO2 adsorption capacity in Wollastonite using atomistic simulation. J CO2 UTIL 2021. [DOI: 10.1016/j.jcou.2021.101564] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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13
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Rheology, Hydration, and Microstructure of Portland Cement Pastes Produced with Ground Açaí Fibers. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11073036] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Açaí (Euterpe oleracea) is a Brazilian typical fruit that is enveloped by natural fibers. This work investigated the effect of incorporating ground açaí fibers (in natura and chemically treated with NaOH and HCl) in 5–10 wt.% replacement of Portland cement on the rheology, hydration, and microstructure of pastes. Rotational rheometry, isothermal calorimetry, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) were performed to evaluate the cement pastes, in addition to SEM-EDS, FTIR, zeta potential, and XRD for fiber characterization. The results showed that the chemical treatment reduced the cellulose and lignin contents in açaí fibers while increasing its surface roughness. The addition of 5% of either fiber slightly increased the yield stress and viscosity of paste, while 10% addition drastically increased these properties, reaching yield stress and viscosity values respectively 40 and 8 times higher than those of plain paste. The incorporation of 5% in natura fibers delayed the cement hydration by about 2.5 days while 10% in natura fibers delayed it by over 160 h. The chemical treatment significantly reduced this retarding effect, leading to a 3 h delay when 5% treated fibers were incorporated. Overall, the combined NaOH/HCl treatment was effective for açaí fibers functionalization and these fibers can be used in cementitious composites.
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Barzgar S, Lothenbach B, Tarik M, Di Giacomo A, Ludwig C. The effect of sodium hydroxide on Al uptake by calcium silicate hydrates (CSH). J Colloid Interface Sci 2020; 572:246-256. [PMID: 32247198 DOI: 10.1016/j.jcis.2020.03.057] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/25/2020] [Accepted: 03/16/2020] [Indexed: 10/24/2022]
Abstract
To reduce the CO2 emissions from cement production, Portland cement (PC) is partially replaced by supplementary cementitious materials (SCM). Reactions of SCM with PC during hydration leads to the formation of CSH with more silicon and aluminum than in PC, which affects the stability and durability of such concrete. Therefore, it is crucial to determine the role of aluminum on CSH properties to predict the formed hydrate phase assemblages and their effects on durability. Aluminum sorption isotherms including very low Al concentrations have been determined for CSH with Ca/Si ratios from 0.6 to 1.4. Elemental measurements were performed with ICP-MS and ICP-OES. The presence of secondary phases was investigated by using thermogravimetric analysis and XRD. Higher dissolved concentrations of Al were observed at increased alkali hydroxide concentrations and thus higher pH values. High alkali hydroxide led to an increased Al(OH)4- formation, which reduced the Al uptake in CSH. This comparable behavior of Al and Si towards changes in pH values, points toward the uptake of aluminum within the silica chain both at low and high Ca/Si ratios. A higher Al uptake in CSH was observed at higher Ca/Si ratios, which indicates a stabilizing effect of calcium in the interlayer on Al uptake.
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Affiliation(s)
- Sonya Barzgar
- Empa, Laboratory for Concrete / Construction Chemistry, CH-8610 Dübendorf, Switzerland; École Polytechnique Fédéral de Lausanne (EPFL), ENAC IIE GR-LUD, CH-1015 Lausanne, Switzerland.
| | - Barbara Lothenbach
- Empa, Laboratory for Concrete / Construction Chemistry, CH-8610 Dübendorf, Switzerland; NTNU, Department of Structural Engineering, Trondheim, Norway.
| | - Mohamed Tarik
- Paul Scherrer Institute (PSI), ENE LBK CPM, 5232 Villigen PSI, Switzerland.
| | - Alessio Di Giacomo
- Empa, Laboratory for Concrete / Construction Chemistry, CH-8610 Dübendorf, Switzerland.
| | - Christian Ludwig
- École Polytechnique Fédéral de Lausanne (EPFL), ENAC IIE GR-LUD, CH-1015 Lausanne, Switzerland; Paul Scherrer Institute (PSI), ENE LBK CPM, 5232 Villigen PSI, Switzerland.
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15
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Kunhi Mohamed A, Moutzouri P, Berruyer P, Walder BJ, Siramanont J, Harris M, Negroni M, Galmarini SC, Parker SC, Scrivener KL, Emsley L, Bowen P. The Atomic-Level Structure of Cementitious Calcium Aluminate Silicate Hydrate. J Am Chem Soc 2020; 142:11060-11071. [PMID: 32406680 DOI: 10.1021/jacs.0c02988] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Despite use of blended cements containing significant amounts of aluminum for over 30 years, the structural nature of aluminum in the main hydration product, calcium aluminate silicate hydrate (C-A-S-H), remains elusive. Using first-principles calculations, we predict that aluminum is incorporated into the bridging sites of the linear silicate chains and that at high Ca:Si and H2O ratios, the stable coordination number of aluminum is six. Specifically, we predict that silicate-bridging [AlO2(OH)4]5- complexes are favored, stabilized by hydroxyl ligands and charge balancing calcium ions in the interlayer space. This structure is then confirmed experimentally by one- and two-dimensional dynamic nuclear polarization enhanced 27Al and 29Si solid-state NMR experiments. We notably assign a narrow 27Al NMR signal at 5 ppm to the silicate-bridging [AlO2(OH)4]5- sites and show that this signal correlates to 29Si NMR signals from silicates in C-A-S-H, conflicting with its conventional assignment to a "third aluminate hydrate" (TAH) phase. We therefore conclude that TAH does not exist. This resolves a long-standing dilemma about the location and nature of the six-fold-coordinated aluminum observed by 27Al NMR in C-A-S-H samples.
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Affiliation(s)
- Aslam Kunhi Mohamed
- Laboratory of Construction Materials, Institut des Matériaux, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.,Institute for Building Materials, Department of Civil, Environmental and Geomatic Engineering, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Pinelopi Moutzouri
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Pierrick Berruyer
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Brennan J Walder
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jirawan Siramanont
- Laboratory of Construction Materials, Institut des Matériaux, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.,SCG CEMENT Co., Ltd., Saraburi 18260, Thailand
| | - Maya Harris
- Laboratory of Construction Materials, Institut des Matériaux, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Mattia Negroni
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sandra C Galmarini
- Building Energy Materials and Components, EMPA, CH-8600 Dübendorf, Switzerland
| | - Stephen C Parker
- Computational Solid State Chemistry Group, Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Karen L Scrivener
- Laboratory of Construction Materials, Institut des Matériaux, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Paul Bowen
- Laboratory of Construction Materials, Institut des Matériaux, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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16
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Park S, Yoon HN, Seo J, Lee HK, Jang JG. Structural evolution of binder gel in alkali-activated cements exposed to electrically accelerated leaching conditions. JOURNAL OF HAZARDOUS MATERIALS 2020; 387:121825. [PMID: 31892426 DOI: 10.1016/j.jhazmat.2019.121825] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 12/02/2019] [Accepted: 12/03/2019] [Indexed: 06/10/2023]
Abstract
The structural evolution of a binder gel in alkali-activated cements exposed to accelerated leaching conditions is investigated for the first time. Samples incorporating fly ash and/or slag were synthesized and were exposed to electrically accelerated leaching by applying a current density of 5 A/m2. The leaching behavior of the samples greatly depended on the binder gel formed in the samples. The N-A-S-H type gel abundant in fly ash-rich samples showed some extent of dissolution upon accelerated leaching, while slag-rich samples underwent hydration of the anhydrous slag after leaching. The obtained results are discussed in view of the degradation of the binder gel induced by accelerated leaching, and their potential performance under repository conditions where groundwater-induced leaching is the main durability concern.
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Affiliation(s)
- Solmoi Park
- Applied Science Research Institute, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - H N Yoon
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Joonho Seo
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - H K Lee
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jeong Gook Jang
- Division of Architecture and Urban Design, Institute of Urban Science, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon, 22012, Republic of Korea.
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17
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Chen H, Yuan H, Mao L, Hashmi MZ, Xu F, Tang X. Stabilization/solidification of chromium-bearing electroplating sludge with alkali-activated slag binders. CHEMOSPHERE 2020; 240:124885. [PMID: 31568939 DOI: 10.1016/j.chemosphere.2019.124885] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 09/10/2019] [Accepted: 09/16/2019] [Indexed: 06/10/2023]
Abstract
Chromium (Cr)-bearing electroplating sludge is a hazardous solid waste and has a detrimental effect on human health and the environment. In this study, an alkali-activated slag binders, namely, formed by the reaction of blast furnace slag (BFS) with alkali, was applied to the stabilization/solidification (S/S) of electroplating sludge. The effects of liquid-solid ratio, water glass modulus ratio (molar ratio of SiO2 to Na2O), water glass dosage, and electroplating sludge amount on the compressive strength and Cr leachability of binders were analyzed. The related mechanism of the S/S of electroplating sludge was discussed on the basis of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy coupled with energy-dispersive spectrometry (SEM-EDS). Results showed that the compressive strength of the alkali-activated slag binder first increased and then remained stable with the increase in liquid-solid ratio, water glass modulus ratio, and water glass dosage. By contrast, the leaching concentrations of Cr(VI) and total Cr decreased with the increase in liquid-solid ratio, water glass modulus ratio, water glass dosage, and curing time. In addition, XRD, FTIR, and SEM-EDS revealed that the hydration products of the binders were mainly low-crystallinity and dense calcium silicate hydrate gels, and Cr(VI) had been effectively immobilized in the structure. The reduction in Cr(VI) by the reductive components in the BFS boosted the stabilization of Cr-bearing electroplating sludge. Overall, the BFS binders containing electroplating sludge had relatively high compressive strengths and low Cr(VI) leaching concentrations. The physical encapsulation, chemical bonding, and absorption contributed the Cr immobilization during the S/S process of electroplating sludge.
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Affiliation(s)
- Huxing Chen
- School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Honghong Yuan
- Institute of Soil and Water Resources and Environmental Science, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Linqing Mao
- School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | | | - Fangnan Xu
- School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xianjin Tang
- Institute of Soil and Water Resources and Environmental Science, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China.
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18
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Liu J, Yi C, Zhu H, Ma H. Property Comparison of Alkali-Activated Carbon Steel Slag (CSS) and Stainless Steel Slag (SSS) and Role of Blast Furnace Slag (BFS) Chemical Composition. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E3307. [PMID: 31614483 PMCID: PMC6829498 DOI: 10.3390/ma12203307] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 09/25/2019] [Accepted: 10/09/2019] [Indexed: 11/16/2022]
Abstract
In order to compare the properties of alkali-activated carbon steel slag (CSS) and stainless steel slag (SSS), the effects of sodium hydroxide/sodium silicate solution mass ratio (NH/NS), liquid/solid ratio and blast furnace slag (BFS) dosage on the compressive strength, hydration products and hydration degree of CSS and SSS were studied. Furthermore, a combination of X-ray diffraction (XRD), thermo-gravimetric analysis coupled with differential thermal analysis (TGA-DTA), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope-energy dispersive spectrometer (SEM-EDS) were used to characterize the morphology and structure of alkali-activated CSS-BFS and SSS-BFS cementitious materials. As the results revealed, the primary hydrate of alkali-activated CSS and SSS is C-(A)-S-H with Q2 [SiO4] units, which has a low Ca/Si ratio and includes inert phases like a CaO-FeO-MnO-MgO solid solution (RO) in CSS while cuspidine, magnesiochromite etc. in SSS. More active C3S and β-C2S promote the alkali activation of CSS, whereas the less active γ-C2S hinders the depolymerization of SSS. The incorporation of BFS does not change the hydrate, whose seed effect is helpful for accelerating the depolymerization and polycondensation of CSS and SSS, especially for SSS, and makes the hydrate increase significantly. Owing to the high SiO2 and Al2O3 contents of SSS, the C-(A)-S-H chain length is increased, thus facilitating the polycondensation effect. In this study, the optimal NH/NS of CSS and SSS is NH/NS= 1:2, and the optimal liquid/solid ratio is 0.29. Compared to CSS-BFS, the C-(A)-S-H gel produced by SSS-BFS has lower Ca/Si and Al/Si ratios. Unlike CSS, pure SSS is inappropriate as an alkali-activated precursor and needs to be co-activated with BFS.
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Affiliation(s)
- Jinyan Liu
- School of Mechanics and Civil Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China.
- Department of Civil Engineering, Shanxi University, Taiyuan 030006, China.
| | - Cheng Yi
- School of Mechanics and Civil Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China
| | - Hongguang Zhu
- School of Mechanics and Civil Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China
| | - Hongqiang Ma
- School of Mechanics and Civil Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China
- Department of Civil and Natural Resources Engineering, University of Canterbury, Christchurch 8041, New Zealand
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19
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Investigating the Effects of Polyaluminum Chloride on the Properties of Ordinary Portland Cement. MATERIALS 2019; 12:ma12203290. [PMID: 31658761 PMCID: PMC6829888 DOI: 10.3390/ma12203290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 10/05/2019] [Accepted: 10/08/2019] [Indexed: 11/29/2022]
Abstract
This study investigates the mechanical and microstructural properties of paste comprising ordinary Portland cement (OPC) added with polyaluminum chloride (PACl). The properties of the resulting mixture are analyzed using compressive strength, X-ray diffraction, scanning electron microscopy (SEM), mercury intrusion porosimetry, and thermogravimetric analysis. The results show that the addition of PACl improves the mechanical properties of OPC paste, that calcium-(aluminum)-silicate-hydrate (C-(A)-S-H) gel and Friedel’s salt are the major products forming from the reaction with the aluminum and chloride ions in PACl, and that the portlandite content decreases. Moreover, the size and number of micropores decrease, and compressive strength increases. All these phenomena are amplified by increasing PACl content. SEM images confirm these findings by revealing Friedel’s salt in the micropores. Thus, this work confirms that adding PACl to OPC results in a mixture with superior mechanical and microstructural properties.
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20
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Hughes CE, Walkley B, Gardner LJ, Walling SA, Bernal SA, Iuga D, Provis JL, Harris KDM. Exploiting in-situ solid-state NMR spectroscopy to probe the early stages of hydration of calcium aluminate cement. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019. [PMID: 30772677 DOI: 10.1016/j.mtadv.2019.100007] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We report a high-field in-situ solid-state NMR study of the hydration of CaAl2O4 (the most important hydraulic phase in calcium aluminate cement), based on time-resolved measurements of solid-state 27Al NMR spectra during the early stages of the reaction. A variant of the CLASSIC NMR methodology, involving alternate recording of direct-excitation and MQMAS 27Al NMR spectra, was used to monitor the 27Al species present in both the solid and liquid phases as a function of time. Our results provide quantitative information on the changes in the relative amounts of 27Al sites with tetrahedral coordination (the anhydrous reactant phase) and octahedral coordination (the hydrated product phases) as a function of time, and reveal significantly different kinetic and mechanistic behaviour of the hydration reaction at the different temperatures (20 °C and 60 °C) studied.
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Affiliation(s)
- Colan E Hughes
- School of Chemistry, Cardiff University, Park Place, Cardiff, Wales, CF10 3AT, UK
| | - Brant Walkley
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK
| | - Laura J Gardner
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK
| | - Samuel A Walling
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK
| | - Susan A Bernal
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK; School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Dinu Iuga
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
| | - John L Provis
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK.
| | - Kenneth D M Harris
- School of Chemistry, Cardiff University, Park Place, Cardiff, Wales, CF10 3AT, UK.
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21
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Maragh JM, Weaver JC, Masic A. Large-scale micron-order 3D surface correlative chemical imaging of ancient Roman concrete. PLoS One 2019; 14:e0210710. [PMID: 30726243 PMCID: PMC6364879 DOI: 10.1371/journal.pone.0210710] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 12/31/2018] [Indexed: 11/19/2022] Open
Abstract
There has been significant progress in recent years aimed at the development of new analytical techniques for investigating structure-function relationships in hierarchically ordered materials. Inspired by these technological advances and the potential for applying these approaches to the study of construction materials from antiquity, we present a new set of high throughput characterization tools for investigating ancient Roman concrete, which like many ancient construction materials, exhibits compositional heterogeneity and structural complexity across multiple length scales. The detailed characterization of ancient Roman concrete at each of these scales is important for understanding its mechanics, resilience, degradation pathways, and for making informed decisions regarding its preservation. In this multi-scale characterization investigation of ancient Roman concrete samples collected from the ancient city of Privernum (Priverno, Italy), cm-scale maps with micron-scale features were collected using multi-detector energy dispersive spectroscopy (EDS) and confocal Raman microscopy on both polished cross-sections and topographically complex fracture surfaces to extract both bulk and surface information. Raman spectroscopy was used for chemical profiling and phase characterization, and data collected using EDS was used to construct ternary diagrams to supplement our understanding of the different phases. We also present a methodology for correlating data collected using different techniques on the same sample at different orientations, which shows remarkable potential in using complementary characterization approaches in the study of heterogeneous materials with complex surface topographies.
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Affiliation(s)
- Janille M. Maragh
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - James C. Weaver
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts, United States of America
| | - Admir Masic
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail:
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22
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Performance of Date Palm Ash as a Cementitious Material by Evaluating Strength, Durability, and Characterization. BUILDINGS 2018. [DOI: 10.3390/buildings9010006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cement manufacturing is indeed a major contributor to global warming that involves energy-intensive production processes along with emitting huge greenhouse gasses into the atmosphere. To adopt sustainable construction practices, agro-industrial waste materials as supplementary cementitious materials (SCMs) have been used by numerous researchers to partially replace conventional ordinary Portland cement (OPC) with SCMs by evaluating its optimum replacement dosage. This study aims to: (1) highlight the background of the date palm tree and the application of date palm waste as a construction material; (2) optimizing the dosage of date palm ash (DPA) as a cementitious material, at the replacement level of 10%, 20%, and 30%; and (3) understand the reaction kinetics by way of characterization techniques. DPA-based binary mixes were compared with each other and with the control (100% OPC mix) through fresh, mechanical, durability, and microstructural properties. The mechanism of reaction at early- and long-term period of curing was studied by characterization tests on paste, including nitrogen adsorption test (BET), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR). The outcome revealed 10% DPA as a strong and durable substitute to OPC, by formation of more Calcium Silicate Hydrate (C-S-H) and Calcium Aluminosilicate Hydrate (C-A-S-H) gel, whereas up to 30% DPA replacement can further maximize clinker replacement with reasonable performance, together with enhanced sustainability and reduced construction cost.
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23
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Park SM, Jang JG, Lee HK. Unlocking the role of MgO in the carbonation of alkali-activated slag cement. Inorg Chem Front 2018. [DOI: 10.1039/c7qi00754j] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
MgO incorporation into alkali-activated slag cement reduces the rate of carbonation.
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Affiliation(s)
- S. M. Park
- Department of Civil and Environmental Engineering
- Korea Advanced Institute of Science and Technology
- Daejeon 34141
- Republic of Korea
| | - J. G. Jang
- Division of Architecture and Urban Design
- Incheon National University
- Incheon
- Republic of Korea
| | - H. K. Lee
- Department of Civil and Environmental Engineering
- Korea Advanced Institute of Science and Technology
- Daejeon 34141
- Republic of Korea
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Zuleta F, Murciano A, Gehrke SA, Maté-Sánchez de Val JE, Calvo-Guirado JL, De Aza PN. A New Biphasic Dicalcium Silicate Bone Cement Implant. MATERIALS 2017; 10:ma10070758. [PMID: 28773119 PMCID: PMC5551801 DOI: 10.3390/ma10070758] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/01/2017] [Accepted: 07/03/2017] [Indexed: 12/12/2022]
Abstract
This study aimed to investigate the processing parameters and biocompatibility of a novel biphasic dicalcium silicate (C2S) cement. Biphasic α´L + β-C2Sss was synthesized by solid-state processing, and was used as a raw material to prepare the cement. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid (SBF) and human adipose stem cell cultures. Two critical-sized defects of 6 mm Ø were created in 15 NZ tibias. A porous cement made of the high temperature forms of C2S, with a low phosphorous substitution level, was produced. An apatite-like layer covered the cement’s surface after soaking in SBF. The cell attachment test showed that α´L + β-C2Sss supported cells sticking and spreading after 24 h of culture. The cement paste (55.86 ± 0.23) obtained higher bone-to-implant contact (BIC) percentage values (better quality, closer contact) in the histomorphometric analysis, and defect closure was significant compared to the control group (plastic). The residual material volume of the porous cement was 35.42 ± 2.08% of the initial value. The highest BIC and bone formation percentages were obtained on day 60. These results suggest that the cement paste is advantageous for initial bone regeneration.
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Affiliation(s)
- Fausto Zuleta
- Escuela de Arquitectura y Diseño, Universidad Pontificia Bolivariana, Circular 1 N° 70-01, Bloque 10 Of 306, Medellín-Antioquia 050031, Colombia.
| | - Angel Murciano
- Departamento de Materiales, Óptica y Tecnologia Electrónica, Universidad Miguel Hernández, Avda. Universidad s/n, 03202-Elche, Alicante, Spain.
| | - Sergio A Gehrke
- Biotecnos Research Center, Rua Dr. Bonazo n° 57, Santa Maria (RS) 97015-001, Brazil.
| | - José E Maté-Sánchez de Val
- Cátedra Internacional de Investigación en Odontología, Universidad Católica San Antonio de Murcia, Avda. Jerónimos, 135, 30107 Guadalupe, Murcia, Spain.
| | - José L Calvo-Guirado
- Cátedra Internacional de Investigación en Odontología, Universidad Católica San Antonio de Murcia, Avda. Jerónimos, 135, 30107 Guadalupe, Murcia, Spain.
| | - Piedad N De Aza
- Instituto de Bioingenieria, Universidad Miguel Hernandez, Avda. Ferrocarril s/n, 03202-Elche, Alicante, Spain.
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25
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Wang KT, Du LQ, Lv XS, He Y, Cui XM. Preparation of drying powder inorganic polymer cement based on alkali-activated slag technology. POWDER TECHNOL 2017. [DOI: 10.1016/j.powtec.2017.02.036] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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26
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Aluminum-induced dreierketten chain cross-links increase the mechanical properties of nanocrystalline calcium aluminosilicate hydrate. Sci Rep 2017; 7:44032. [PMID: 28281635 PMCID: PMC5345016 DOI: 10.1038/srep44032] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 01/31/2017] [Indexed: 11/10/2022] Open
Abstract
The incorporation of Al and increased curing temperature promotes the crystallization and cross-linking of calcium (alumino)silicate hydrate (C-(A-)S-H), which is the primary binding phase in most contemporary concrete materials. However, the influence of Al-induced structural changes on the mechanical properties at atomistic scale is not well understood. Herein, synchrotron radiation-based high-pressure X-ray diffraction is used to quantify the influence of dreierketten chain cross-linking on the anisotropic mechanical behavior of C-(A-)S-H. We show that the ab-planar stiffness is independent of dreierketten chain defects, e.g. vacancies in bridging tetrahedra sites and Al for Si substitution. The c-axis of non-cross-linked C-(A-)S-H is more deformable due to the softer interlayer opening but stiffens with decreased spacing and/or increased zeolitic water and Ca2+ of the interlayer. Dreierketten chain cross-links act as ‘columns’ to resist compression, thus increasing the bulk modulus of C-(A-)S-H. We provide the first experimental evidence on the influence of the Al-induced atomistic configurational change on the mechanical properties of C-(A-)S-H. Our work advances the fundamental knowledge of C-(A-)S-H on the lowest level of its hierarchical structure, and thus can impact the way that innovative C-(A-)S-H-based cementitious materials are developed using a ‘bottom-up’ approach.
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Ortaboy S, Li J, Geng G, Myers RJ, Monteiro PJM, Maboudian R, Carraro C. Effects of CO2 and temperature on the structure and chemistry of C–(A–)S–H investigated by Raman spectroscopy. RSC Adv 2017. [DOI: 10.1039/c7ra07266j] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Calcium (alumino)silicate hydrate (C–(A–)S–H) is the critical binding phase in modern Portland cement-based concrete, yet the relationship between its structure and stoichiometry is not completely understood.
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Affiliation(s)
- Sinem Ortaboy
- Department of Chemical and Biomolecular Engineering
- University of California
- Berkeley
- USA
- Chemistry Department
| | - Jiaqi Li
- Department of Civil and Environmental Engineering
- University of California
- Berkeley
- USA
| | - Guoqing Geng
- Department of Civil and Environmental Engineering
- University of California
- Berkeley
- USA
| | - Rupert J. Myers
- Department of Civil and Environmental Engineering
- University of California
- Berkeley
- USA
- School of Engineering
| | - Paulo J. M. Monteiro
- Department of Civil and Environmental Engineering
- University of California
- Berkeley
- USA
| | - Roya Maboudian
- Department of Chemical and Biomolecular Engineering
- University of California
- Berkeley
- USA
| | - Carlo Carraro
- Department of Chemical and Biomolecular Engineering
- University of California
- Berkeley
- USA
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28
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Roosz C, Gaboreau S, Grangeon S, Prêt D, Montouillout V, Maubec N, Ory S, Blanc P, Vieillard P, Henocq P. Distribution of Water in Synthetic Calcium Silicate Hydrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:6794-6805. [PMID: 27281114 DOI: 10.1021/acs.langmuir.6b00878] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Understanding calcium silicate hydrates (CSHs) is of paramount importance for understanding the behavior of cement materials because they control most of the properties of these man-made materials. The atomic scale water content and structure have a major influence on their properties, as is analogous with clay minerals, and we should assess these. Here, we used a multiple analytical approach to quantify water distribution in CSH samples and to determine the relative proportions of water sorbed on external and internal (interlayer) surfaces. Water vapor isotherms were used to explain the water distribution in the CSH microstructure. As with many layered compounds, CSHs have external and internal (interlayer) surfaces displaying multilayer adsorption of water molecules on external surfaces owing to the hydrophilic surfaces. Interlayer water was also quantified from water vapor isotherm, X-ray diffraction (XRD), and thermal gravimetric analyses (TGA) data, displaying nonreversible swelling/shrinkage behavior in response to drying/rewetting cycles. From this quantification and balance of water distribution, we were able to explain most of the widely dispersed data already published according to the various relative humidity (RH) conditions and measurement techniques. Stoichiometric formulas were proposed for the different CSH samples analyzed (0.6 < Ca/Si < 1.6), considering the interlayer water contribution.
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Affiliation(s)
- C Roosz
- UMR CNRS 7285 IC2MP, Université de Poitiers , Equipe HydrASA, rue Albert Turpain, Bat B8, 86022 Poitiers, France
- Environment and Process Division, BRGM , 3, avenue Claude Guillemin, F-45060 Orléans Cedex 2, France
- Andra , 1/7 rue Jean Monnet, Parc de la Croix Blanche, 92298 Châtenay-Malabry Cedex, France
| | - S Gaboreau
- Environment and Process Division, BRGM , 3, avenue Claude Guillemin, F-45060 Orléans Cedex 2, France
| | - S Grangeon
- Environment and Process Division, BRGM , 3, avenue Claude Guillemin, F-45060 Orléans Cedex 2, France
| | - D Prêt
- UMR CNRS 7285 IC2MP, Université de Poitiers , Equipe HydrASA, rue Albert Turpain, Bat B8, 86022 Poitiers, France
| | - V Montouillout
- CNRS-CEMHTI UPR 3079 , 1D Avenue de la Recherche Scientifique, 45071 Orléans Cedex 2, France
| | - N Maubec
- Environment and Process Division, BRGM , 3, avenue Claude Guillemin, F-45060 Orléans Cedex 2, France
| | - S Ory
- CNRS-CEMHTI UPR 3079 , 1D Avenue de la Recherche Scientifique, 45071 Orléans Cedex 2, France
| | - P Blanc
- Environment and Process Division, BRGM , 3, avenue Claude Guillemin, F-45060 Orléans Cedex 2, France
| | - P Vieillard
- UMR CNRS 7285 IC2MP, Université de Poitiers , Equipe HydrASA, rue Albert Turpain, Bat B8, 86022 Poitiers, France
| | - P Henocq
- Andra , 1/7 rue Jean Monnet, Parc de la Croix Blanche, 92298 Châtenay-Malabry Cedex, France
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29
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Allahverdi A, Pilehvar S, Mahinroosta M. Influence of curing conditions on the mechanical and physical properties of chemically-activated phosphorous slag cement. POWDER TECHNOL 2016. [DOI: 10.1016/j.powtec.2015.10.053] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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30
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Myers RJ, L'Hôpital E, Provis JL, Lothenbach B. Composition–solubility–structure relationships in calcium (alkali) aluminosilicate hydrate (C-(N,K-)A-S-H). Dalton Trans 2015; 44:13530-44. [PMID: 26134354 DOI: 10.1039/c5dt01124h] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Solubility–structure–composition relationships in calcium (alkali) aluminosilicate hydrate (C-(N,K-)A-S-H) are analysed, including the mean chain length, basal spacing and cross-linking.
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Affiliation(s)
- Rupert J. Myers
- Department of Materials Science and Engineering
- University of Sheffield
- Sheffield
- UK
- Laboratory for Concrete and Construction Chemistry
| | - Emilie L'Hôpital
- Laboratory for Concrete and Construction Chemistry
- EMPA
- Dübendorf
- Switzerland
| | - John L. Provis
- Department of Materials Science and Engineering
- University of Sheffield
- Sheffield
- UK
| | - Barbara Lothenbach
- Laboratory for Concrete and Construction Chemistry
- EMPA
- Dübendorf
- Switzerland
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31
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Richardson IG. Model structures for C-(A)-S-H(I). ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2014; 70:903-923. [PMID: 25449614 PMCID: PMC4468512 DOI: 10.1107/s2052520614021982] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 10/06/2014] [Indexed: 05/28/2023]
Abstract
C-(A)-S-H(I) is a calcium silicate hydrate that is studied extensively as a model for the main binding phase in concrete. It is a structurally imperfect form of 14 Å tobermorite that has variable composition and length of (alumino)silicate anions. New structural-chemical formulae are presented for single- and double-chain tobermorite-based phases and equations are provided that can be used to calculate a number of useful quantities from (29)Si NMR data. It is shown that there are no interlayer calcium ions when the silicate chains are of infinite length and that one is added for each tetrahedral `bridging' site that is vacant. Preparations that have Ca/Si greater than about 1.4 include an intermixed Ca-rich phase. It is not possible to generate a structural model for a dimer that is crystal-chemically consistent with known calcium silicate hydrates if the starting structure is an orthotobermorite, i.e. of the type that has been used in all previous studies. Crystal-chemically plausible models are developed that are based instead on clinotobermorite. A number of models that represent different mean chain lengths are developed using crystal-chemical and geometrical reasoning. The models account for experimental observations, including variations in Ca/Si, H2O/Si, (alumino)silicate anion structure and layer spacing.
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Affiliation(s)
- Ian G. Richardson
- School of Civil Engineering, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, England
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32
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Allahverdi A, Ahmadnezhad S. Mechanical activation of silicomanganese slag and its influence on the properties of Portland slag cement. POWDER TECHNOL 2014. [DOI: 10.1016/j.powtec.2013.10.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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33
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Correa D, Almirall A, García-Carrodeguas R, dos Santos LA, De Aza AH, Parra J, Delgado JÁ. β-Dicalcium silicate-based cement: synthesis, characterization and in vitro bioactivity and biocompatibility studies. J Biomed Mater Res A 2013; 102:3693-703. [PMID: 24277585 DOI: 10.1002/jbm.a.35041] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 10/28/2013] [Accepted: 11/18/2013] [Indexed: 12/27/2022]
Abstract
β-dicalcium silicate (β-Ca₂ SiO₄, β-C₂ S) is one of the main constituents in Portland cement clinker and many refractory materials, itself is a hydraulic cement that reacts with water or aqueous solution at room/body temperature to form a hydrated phase (C-S-H), which provides mechanical strength to the end product. In the present investigation, β-C₂ S was synthesized by sol-gel process and it was used as powder to cement preparation, named CSiC. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid solutions and human osteoblast cell cultures for various time periods, respectively. The results showed that the sol-gel process is an available synthesis method in order to obtain a pure powder of β-C₂ S at relatively low temperatures without chemical stabilizers. A bone-like apatite layer covered the material surface after soaking in SBF and its compressive strength (CSiC cement) was comparable with that of the human trabecular bone. The extracts of this cement were not cytotoxic and the cell growth and relative cell viability were comparable to negative control.
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Affiliation(s)
- Daniel Correa
- Departamento de Cerámicas y Composites, Centro de Biomateriales, Universidad de La Habana, 10400, La Habana, Cuba
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34
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Allahverdi A, Mahinroosta M. Mechanical activation of chemically activated high phosphorous slag content cement. POWDER TECHNOL 2013. [DOI: 10.1016/j.powtec.2013.04.037] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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35
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Myers RJ, Bernal SA, San Nicolas R, Provis JL. Generalized structural description of calcium-sodium aluminosilicate hydrate gels: the cross-linked substituted tobermorite model. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:5294-5306. [PMID: 23534827 DOI: 10.1021/la4000473] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Structural models for the primary strength and durability-giving reaction product in modern cements, a calcium (alumino)silicate hydrate gel, have previously been based solely on non-cross-linked tobermorite structures. However, recent experimental studies of laboratory-synthesized and alkali-activated slag (AAS) binders have indicated that the calcium-sodium aluminosilicate hydrate [C-(N)-A-S-H] gel formed in these systems can be significantly cross-linked. Here, we propose a model that describes the C-(N)-A-S-H gel as a mixture of cross-linked and non-cross-linked tobermorite-based structures (the cross-linked substituted tobermorite model, CSTM), which can more appropriately describe the spectroscopic and density information available for this material. Analysis of the phase assemblage and Al coordination environments of AAS binders shows that it is not possible to fully account for the chemistry of AAS by use of the assumption that all of the tetrahedral Al is present in a tobermorite-type C-(N)-A-S-H gel, due to the structural constraints of the gel. Application of the CSTM can for the first time reconcile this information, indicating the presence of an additional activation product that contains highly connected four-coordinated silicate and aluminate species. The CSTM therefore provides a more advanced description of the chemistry and structure of calcium-sodium aluminosilicate gel structures than that previously established in the literature.
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Affiliation(s)
- Rupert J Myers
- Department of Materials Science and Engineering, Sir Robert Hadfield Building, Mappin St., University of Sheffield, Sheffield S1 3JD, UK
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36
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Renaudin G, Russias J, Leroux F, Frizon F, Cau-dit-Coumes C. Structural characterization of C–S–H and C–A–S–H samples—Part I: Long-range order investigated by Rietveld analyses. J SOLID STATE CHEM 2009. [DOI: 10.1016/j.jssc.2009.09.026] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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