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Modeling of alkali-silica reaction in concrete: a review

J.W. PAN, Y.T. FENG, J.T. WANG, Q.C. SUN, C.H. ZHANG, D.R.J. OWEN

《结构与土木工程前沿（英文）》 2012年 第6卷 第1期   页码 1-18 doi: 10.1007/s11709-012-0141-2

摘要： This paper presents a comprehensive review of modeling of alkali-silica reaction (ASR) in concrete. Such modeling is essential for investigating the chemical expansion mechanism and the subsequent influence on the mechanical aspects of the material. The concept of ASR and the mechanism of expansion are first outlined, and the state-of-the-art of modeling for ASR, the focus of the paper, is then presented in detail. The modeling includes theoretical approaches, meso- and macroscopic models for ASR analysis. The theoretical approaches dealt with the chemical reaction mechanism and were used for predicting pessimum size of aggregate. Mesoscopic models have attempted to explain the mechanism of mechanical deterioration of ASR-affected concrete at material scale. The macroscopic models, chemo-mechanical coupling models, have been generally developed by combining the chemical reaction kinetics with linear or nonlinear mechanical constitutive, and were applied to reproduce and predict the long-term behavior of structures suffering from ASR. Finally, a conclusion and discussion of the modeling are given.

关键词： alkali-silica reaction (ASR)     modeling     concrete     mesoscopic     macroscopic    

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碱硅酸反应与碱碳酸盐反应

唐明述

《中国工程科学》 2000年 第2卷 第1期   页码 34-40

摘要：

碱集料反应（AAR）可分为两类，即碱硅酸反应（ASR）与碱碳酸盐反应（ACR）。二者的共同点是与碱发生的化学反应可导致混凝土中集料的体积增大，从而可能使混凝土甚至整个建筑物或构筑物发生膨胀开裂。ASR类型岩石具有碱活性的前提条件是较低的二氧化硅结晶完整度。只有隐晶质、微晶质、玻璃质或发生过应变的二氧化硅才会具有较高的化学活性，导致混凝土破坏。

关键词： 碱     集料     硅酸     碳酸盐     混凝土开裂     机理    

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A general framework for modeling long-term behavior of earth and concrete dams

Bernhard A. SCHREFLER, Francesco PESAVENTO, Lorenzo SANAVIA, Giuseppe SCIUME, Stefano SECCHI, Luciano SIMONI

《结构与土木工程前沿（英文）》 2011年 第5卷 第1期   页码 41-52 doi: 10.1007/s11709-010-0070-x

摘要： Many problems are linked with the long-term behavior of both earthdams and concrete dams. They range from hydraulic fracturing to alkali-silica reaction (ASR) and to repair work in concrete dams, from seismic behavior to secondary consolidation in earthdams. A common framework for the simulation of such systems is shown, based on the mechanics of multiphase porous media. The general model is particularized to specific situations and several examples are shown.

关键词： earth dams     concrete dams     multiphase porous materials     coupled problems     hydraulic fracture     concrete hydration     alkali-silica reaction (ASR)     finite element method    

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混凝土中碱硅反应效应的多尺度均质化分析 Article

Roozbeh Rezakhani, Mohammed Alnaggar, Gianluca Cusatis

《工程（英文）》 2019年 第5卷 第6期   页码 1139-1154 doi: 10.1016/j.eng.2019.02.007

摘要：

碱硅反应（ASR）是混凝土结构（如桥梁和水坝）在长期的高湿度环境下发生的主要劣化机制之一。ASR是骨料中活性硅成分与水泥浆中碱金属离子之间发生的一种化学反应。这种化学反应会产生ASR凝胶，该凝胶吸水后膨胀，造成混凝土损坏和开裂，最终导致混凝土力学性能下降。本研究基于晶格离散粒子模型（LDPM），研究了混凝土的ASR损伤。作者已经成功地利用LDPM框架对ASR建模，并且通过实验数据对所得模型ASR-LDPM进行了校准和验证。本研究将ASR-LDPM用作中尺度模型，并采用最新开发的多尺度均质化框架来模拟ASR的宏观尺度效应。作者首先分析了由ASR-LDPM模拟的混凝土代表性体积元（RVE）在拉伸和压缩两种情况下的均质化行为，并研究了ASR对混凝土有效力学性能的影响。

关键词： 多尺度均质化     代表性体积元     碱硅反应     晶格离散粒子模型    

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Porous silica synthesis out of coal fly ash with no residue generation and complete silicon separation

《环境科学与工程前沿（英文）》 2023年 第17卷 第9期 doi: 10.1007/s11783-023-1712-2

摘要：

● Both amorphous and crystalline silicon are completely separated from coal fly ash.

关键词： Coal fly ash     Alkali fusion     Micro-/meso-porous Si     Zeolite MCM-48     Crystalline transformation    

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Operando modeling and measurements: Powerful tools for revealing the mechanism of alkali carbonate-based

《能源前沿（英文）》 2023年 第17卷 第3期   页码 380-389 doi: 10.1007/s11708-023-0872-x

摘要： Alkali carbonate-based sorbents (ACSs), including Na2CO3- and K2CO3-based sorbents, are promising for CO2 capture. However, the complex sorbent components and operation conditions lead to the versatile kinetics of CO2 sorption on these sorbents. This paper proposed that operando modeling and measurements are powerful tools to understand the mechanism of sorbents in real operating conditions, facilitating the sorbent development, reactor design, and operation parameter optimization. It reviewed the theoretical simulation achievements during the development of ACSs. It elucidated the findings obtained by utilizing density functional theory (DFT) calculations, ab initio molecular dynamics (AIMD) simulations, and classical molecular dynamics (CMD) simulations as well. The hygroscopicity of sorbent and the humidity of gas flow are crucial to shifting the carbonation reaction from the gas−solid mode to the gas−liquid mode, boosting the kinetics. Moreover, it briefly introduced a machine learning (ML) approach as a promising method to aid sorbent design. Furthermore, it demonstrated a conceptual compact operando measurement system in order to understand the behavior of ACSs in the real operation process. The proposed measurement system includes a micro fluidized-bed (MFB) reactor for kinetic analysis, a multi-camera sub-system for 3D particle movement tracking, and a combined Raman and IR sub-system for solid/gas components and temperature monitoring. It is believed that this system is useful to evaluate the real-time sorbent performance, validating the theoretical prediction and promoting the industrial scale-up of ACSs for CO2 capture.

关键词： CO2 capture     carbonation     theoretical modeling     operando techniques     reaction visualization    

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Saline-alkali soil reclamation and utilization in China: progress and prospects REVIEW

《农业科学与工程前沿（英文）》 2024年 第11卷 第2期   页码 216-228 doi: 10.15302/J-FASE-2024551

摘要：

Soil salinity is a global threat to the productivity of arable land. With the impact of population growth and development of social economy in China, the area of arable land has been shrinking in recent decades and is approaching a critical threshold of 120 Mha, the minimum area for maintaining the national food security. Saline-alkaline land, as important backup reserve, has been receiving increased attention as an opportunity to expand land resources. This review first summarizes the general principles and technologies of saline soil reclamation to support plant growth, including leaching salts or blocking the rise of salts, and soil fertility enhancement to improve the buffering capacity. Then the progress in this area in China is described including the customization of technologies and practices used in different saline-alkali regions. Following the soil management strategies, the concept of selecting crops for saline soil is proposed. This encompasses halophyte planting, salt-tolerant crop breeding and the application of saline-adapted functional microorganisms to improve the adaptation of crops. Finally, the current problems and challenges are evaluate, and future research directions and prospects proposed for managing this major soil constraint.

关键词： Food security     land reserve     reclamation     saline-alkali soil     utilization    

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Optimizing the compressive strength of concrete containing micro-silica, nano-silica, and polypropylene

Fatemeh ZAHIRI, Hamid ESKANDARI-NADDAF

《结构与土木工程前沿（英文）》 2019年 第13卷 第4期   页码 821-830 doi: 10.1007/s11709-019-0518-6

摘要： Many studies have evaluated the effects of additives such as nano-silica (NS), micro-silica (MS) and polymer fibers on optimizing the mechanical properties of concrete, such as compressive strength. Nowadays, with progress in cement industry provides, it has become possible to produce cement type I with strength classes of 32.5, 42.5, and 52.5 MPa. On the one hand, the microstructure of cement has changed, and modified by NS, MS, and polymers; therefore it is very important to determine the optimal percentage of each additives for those CSCs. In this study, 12 mix designs containing different percentages of MS, NS, and polymer fibers in three cement strength classes(CSCs) (32.5, 42.5, and 52.5 MPa) were designed and constructed based on the mixture method. Results indicated the sensitivity of each CSCs can be different on the NS or MS in compressive strength of concrete. Consequently, strength classes have a significant effect on the amount of MS and NS in mix design of concrete. While, polymer fibers don’t have significant effect in compressive strength considering CSCs.

关键词： mixture method     compressive strength     nano-silica     micro-silica     polypropylene fibers    

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Layered alkali titanates (ATiO): possible uses for energy/environment issues

《能源前沿（英文）》 2021年 第15卷 第3期   页码 631-655 doi: 10.1007/s11708-021-0776-6

摘要： Uses of layered alkali titanates (A2TinO2n+1; Na2Ti3O7, K2Ti4O9, and Cs2Ti5O11) for energy and environmental issues are summarized. Layered alkali titanates of various structural types and compositions are regarded as a class of nanostructured materials based on titanium oxide frameworks. If compared with commonly known titanium dioxides (anatase and rutile), materials design based on layered alkali titanates is quite versatile due to the unique structure (nanosheet) and morphological characters (anisotropic particle shape). Recent development of various synthetic methods (solid-state reaction, flux method, and hydrothermal reaction) for controlling the particle shape and size of layered alkali titanates are discussed. The ion exchange ability of layered alkali titanate is used for the collection of metal ions from water as well as a way of their functionalization. These possible materials design made layered alkali titanates promising for energy (including catalysis, photocatalysts, and battery) and environmental (metal ion concentration from aqueous environments) applications.

关键词： layered alkali titanates     photocatalysis     hydrogen evdution     metal ions collection    

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The development of ultralightweight expanded perlite-based thermal insulation panel using alkali activator

Damla Nur ÇELİK; Gökhan DURMUŞ

《结构与土木工程前沿（英文）》 2022年 第16卷 第11期   页码 1486-1499 doi: 10.1007/s11709-022-0881-6

摘要： The International Energy Agency (IEA) states that global energy consumption will increase by 53% by 2030. Turkey has 70% of the world’s perlite reserves, and in order to reduce energy consumption a thermal insulation panel was developed in Turkey using different particle sizes of expanded perlite (EP). In this study, 0–1.18 mm (powder) and 0–3 mm (granular) EP particle sizes were selected, since they have the lowest thermal conductivity coefficients among all the particle sizes. In addition, an alkali activator solution was used as a binder in the mixtures. The alkaline activator solution was obtained by mixing sodium hydroxide solution (6, 8, 10, and 12 mol·L−1) and sodium silicate (Module 3) at the different ratios of Na2SiO3 to NaOH of 1, 1.5, 2, and 2.5. This study aimed to experimentally determine the optimum binder and distribution ratio of EP, with the lowest coefficient of thermal conductivity and the lowest density. The lowest thermal conductivity and the lowest density were determined as 0.04919 W·m−1·K−1 and 133.267 kg/m3, respectively, in the sample prepared with 83.33% powder-size EP, 6 mol·L−1 sodium hydroxide solution, and ratio of Na2SiO3 to NaOH of 1.5. The density, thermal conductivity, and compressive strength of the sample showed the same trends of behavior when the Na2SiO3 to NaOH ratio was increased. In addition, the highest compressive strength was measured in 12 mol·L−1 NaOH concentration regardless of particle size. In conclusion, the study predicts that the EP-based thermal insulation panel can be used as an insulation material in the construction industry according to the TS825 Thermal Insulation Standard.

关键词： expanded perlite     alkali activator     thermal insulation panel     thermal conductivity    

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Adhesion performance of alkali-activated material for 3-dimensional printing of tunnel linings at different

《结构与土木工程前沿（英文）》 2024年 第18卷 第1期   页码 66-79 doi: 10.1007/s11709-024-1067-1

摘要： Robotic-based technologies such as automated spraying or extrusion-based 3-dimensional (3D) concrete printing can be used to build tunnel linings, aiming at reducing labor and mitigating the associated safety issues, especially in the high-geothermal environment. Extrusion-based 3D concrete printing (3DCP) has additional advantages over automated sprayings, such as improved surface quality and no rebound. However, the effect of different temperatures on the adhesion performance of 3D-printed materials for tunnel linings has not been investigated. This study developed several alkali-activated slag mixtures with different activator modulus ratios to avoid the excessive use of Portland cement and enhance sustainability of 3D printable materials. The thermal responses of the mixtures at different temperatures of 20 and 40 °C were studied. The adhesion strength of the alkali-activated material was evaluated for both early and later ages. Furthermore, the structural evolution of the material exposed to different temperatures was measured. This was followed by microstructure characterization. Results indicate that elevated temperatures accelerate material reactions, resulting in improved early-age adhesion performance. Moreover, higher temperatures contribute to the development of a denser microstructure and enhanced mechanical strength in the hardened stage, particularly in mixtures with higher silicate content.

关键词： alkali-activated material     3DCP     tunnel lining     high-geothermal environment     adhesion    

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Dispersion of “guava-like” silica/polyacrylate nanocomposite particles in polyacrylate matrix

QI Dongming, YANG Lei, WU Minghua, SHAO Jianzhong, BAO Yongzhong

《化学科学与工程前沿（英文）》 2008年 第2卷 第2期   页码 127-134 doi: 10.1007/s11705-008-0033-0

摘要： A series of “guava-like” silica/polyacrylate nanocomposite particles with close silica content and different grafting degrees were prepared via mini-emulsion polymerization using 3-(trimethoxysilyl)propyl methacrylate (TSPM) modified silica/acrylate dispersion. The silica/polyacrylate composite particles were melt-mixed with unfilled polyacrylate (PA) resin to prepare corresponding silica/polyacrylate molded composites and the dispersion mechanism of these silica particles from the “guava-like” composite particles into polyacrylate matrix was studied. It was calculated that about 110 silica particles were accumulated in the bulk of every silica/polyacrylate composite latex particle. Both the solubility tests of silica/polyacrylate composite latex particles in tetrahydrofuran (THF) and the section transmission electron microscope (TEM) micrographs of silica/polyacrylate molded composites indicated that the grafting degree of silica particles played a crucial role in the dispersion of silica/polyacrylate composite particles into the polyacrylate matrix. When the grafting degree of polyacrylate onto silica was in a moderate range (ca. 20%–70%), almost all of silica particles in these “guava-like” composite particles were dispersed into the polyacrylate matrix in a primary-particle-level. However, at a lower grafting degree, massive silica aggregations were found in molded composites because of the lack of steric protection. At a greater grafting degree (i.e., 200%), a cross-linked network was formed in the silica/polyacrylate composite particles, which prevented the dispersion of composite particles in THF and polyacrylate matrix as primary particles.

关键词： silica/polyacrylate composite     cross-linked network     –70     guava-like     TEM    

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Utilization of alkali-activated copper slag as binder in concrete

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 773-780 doi: 10.1007/s11709-021-0722-z

摘要： This study was focused on developing concrete using alkali-activated copper slag (AACS) as a binder. The properties of alkali-activated copper slag concrete (AACSC) were compared with portland cement concrete (PCC). Different AACSC mixes were prepared with varying Na2O dosage (6% and 8% of the binder by weight) and curing methods. Hydration products in AACSC were retrieved using Fourier-transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) techniques. The test results indicate that the workability of AACSC was lesser than that of PCC. The AACSC mix with 6% Na2O dosage has exhibited similar mechanical properties as that of PCC. The mechanical properties of AACSC were higher than PCC when 8% of Na2O dosage was used. Heat curing was effective to upgrade the strength properties of AACSC at an early age of curing, but at a later age mechanical properties of ambient cured and heat-cured AACSC were comparable. The hydration products of AACSC were not identified in XRD patterns, whereas, in FTIR spectra of AACSC some alkali-activated reaction products were reflected. The AACSC mixes were found to be more sustainable than PCC. It has been concluded that AACSC can be produced similarly to that of PCC and ambient curing is sufficient.

关键词： binder     concrete     mechanical properties     mineralogy     workability    

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Enhanced activation of persulfate using mesoporous silica spheres augmented Cu–Al bimetallic oxide particles

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1581-1592 doi: 10.1007/s11705-023-2327-7

摘要： Herein, Cu–Al bimetallic oxide was synthesized and mixed with mesoporous silica spheres via a simple hydrothermal method. The prepared sample was then analyzed and employed to activate potassium peroxydisulfate for bisphenol A removal. Based on the results of X-ray diffraction, scanning electron microscopy, and energy dispersion spectroscopy, Cu–Al bimetallic oxide was determined as CuO-Al2O3, and mesoporous silica spheres were found around the these particles. At 30 min, a bisphenol A degradation level of 90% was achieved, and it remained at over 60% after five consecutive cycles, indicating the catalyst’s superior capacity and stability. In terms of removal performance, the radical pathway (including SO4•‒, OH •, and O2•‒) and singlet oxygen (1O2) played minor roles, while electron migration between bisphenol A, potassium peroxydisulfate, and the catalyst played a dominant role. The introduction of Al2O3 promoted the formation of surface oxygen vacancies, which improved ligand complex formation between potassium peroxydisulfate and the catalyst, thereby facilitating electron migration. Furthermore, mesoporous silica spheres augment not only enhanced bisphenol A adsorption but also alleviated Cu leaching. Overall, this work is expected to provide significant support for the rational development of catalysts with high catalytic activity for persulfate activation via surface electron migration.

关键词： Cu–Al bimetallic oxides     mesoporous silica spheres     peroxydisulfate     bisphenol A    

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Effects of polyethylenimine on the dispersibility of hollow silica nanoparticles

WEN Lixiong, WANG Qing, ZHENG Tianyuan, CHEN Jianfeng

《化学科学与工程前沿（英文）》 2007年 第1卷 第3期   页码 277-282 doi: 10.1007/s11705-007-0050-4

摘要： In this study, two different methods were applied to disperse hollow silica nanoparticles (HSNP); one employed polyethylenimine (PEI) as the dispersant during the synthesis processes for preparing HSNP, while the other added PEI into suspensions of the prepared HSNP and used milling treatment to achieve the desired dispersion. It was found that adding PEI during the synthesis process of HSNP had no noticeable improvement in the dispersion, while adding PEI into suspensions of the prepared HSNP and utilizing milling treatment resulted in remarkable dispersion improvement. Therefore, the latter was chosen as the method in dispersing HSNP suspensions. The adsorption of PEI on the surface of HSNP and the stability of the aqueous suspensions was investigated. The results indicated that the adsorption of PEI on the surface of HSNP would increase the repulsive energy among particles, hence reducing the agglomeration of HSNP and improving the stability of the aqueous suspensions. The change of HSNP’s ζ potential after adding PEI and the relationship between the adsorbed amount of PEI and pH were also investigated.

关键词： dispersion improvement     different     prepared HSNP     relationship     agglomeration    

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标题 作者 时间 类型 操作

Modeling of alkali-silica reaction in concrete: a review

J.W. PAN, Y.T. FENG, J.T. WANG, Q.C. SUN, C.H. ZHANG, D.R.J. OWEN

期刊论文

碱硅酸反应与碱碳酸盐反应

唐明述

期刊论文

A general framework for modeling long-term behavior of earth and concrete dams

Bernhard A. SCHREFLER, Francesco PESAVENTO, Lorenzo SANAVIA, Giuseppe SCIUME, Stefano SECCHI, Luciano SIMONI

期刊论文

混凝土中碱硅反应效应的多尺度均质化分析

Roozbeh Rezakhani, Mohammed Alnaggar, Gianluca Cusatis

期刊论文

Porous silica synthesis out of coal fly ash with no residue generation and complete silicon separation

期刊论文

Operando modeling and measurements: Powerful tools for revealing the mechanism of alkali carbonate-based

期刊论文

Saline-alkali soil reclamation and utilization in China: progress and prospects

期刊论文

Optimizing the compressive strength of concrete containing micro-silica, nano-silica, and polypropylene

Fatemeh ZAHIRI, Hamid ESKANDARI-NADDAF

期刊论文

Layered alkali titanates (ATiO): possible uses for energy/environment issues

期刊论文

The development of ultralightweight expanded perlite-based thermal insulation panel using alkali activator

Damla Nur ÇELİK; Gökhan DURMUŞ

期刊论文

Adhesion performance of alkali-activated material for 3-dimensional printing of tunnel linings at different

期刊论文

Dispersion of “guava-like” silica/polyacrylate nanocomposite particles in polyacrylate matrix

QI Dongming, YANG Lei, WU Minghua, SHAO Jianzhong, BAO Yongzhong

期刊论文

Utilization of alkali-activated copper slag as binder in concrete

期刊论文

Enhanced activation of persulfate using mesoporous silica spheres augmented Cu–Al bimetallic oxide particles

期刊论文

Effects of polyethylenimine on the dispersibility of hollow silica nanoparticles

WEN Lixiong, WANG Qing, ZHENG Tianyuan, CHEN Jianfeng

期刊论文