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地聚合物 2

劣化机理 1

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流变学 1

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碱激发材料 1

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Development of mix design method based on statistical analysis of different factors for geopolymer concrete

Paramveer SINGH; Kanish KAPOOR

《结构与土木工程前沿（英文）》 2022年第16卷第10期页码 1315-1335 doi: 10.1007/s11709-022-0853-x

摘要： The present study proposes the mix design method of Fly Ash (FA) based geopolymer concrete using Response Surface Methodology (RSM). In this method, different factors, including binder content, alkali/binder ratio, NS/NH ratio (sodium silicate/sodium hydroxide), NH molarity, and water/solids ratio were considered for the mix design of geopolymer concrete. The 2D contour plots were used to setup the mix design method to achieve the target compressive strength. The proposed mix design method of geopolymer concrete is divided into three categories based on curing regime, specifically one ambient curing (25 °C) and two heat curing (60 and 90 °C). The proposed mix design method of geopolymer concrete was validated through experimentation of M30, M50, and M70 concrete mixes at all curing regimes. The observed experimental compressive strength results validate the mix design method by more than 90% of their target strength. Furthermore, the current study concluded that the required compressive strength can be achieved by varying any factor in the mix design. In addition, the factor analysis revealed that the NS/NH ratio significantly affects the compressive strength of geopolymer concrete.

关键词： geopolymer concrete mix design fly ash response surface methodology compressive strength stress−strain

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Assessment and prediction of the mechanical properties of ternary geopolymer concrete

Jinliang LIU; Wei ZHAO; Xincheng SU; Xuefeng XIE

《结构与土木工程前沿（英文）》 2022年第16卷第11期页码 1436-1452 doi: 10.1007/s11709-022-0889-y

摘要： This paper utilized granulated blast furnace slag (GBFS), fly ash (FA), and zeolite powder (ZP) as the binders of ternary geopolymer concrete (TGC) activated with sodium silicate solution. The effects of alkali content (AC) and alkaline activator modulus (AAM) on the compressive strength, flexural tensile strength and elastic modulus of TGC were tested and the SEM micrographs were investigated. The experimental results were then compared with the predictions based on models of mechanical properties, and the amended models of TGC were proposed taking account of the effects of AC and AAM. The results indicated that increasing AC and reducing AAM which were in the specific ranges (5% to 7% and 1.1 to 1.5, respectively) had positive effects on the mechanical properties of TGC. In addition, the flexural tensile strength of TGC was 27.7% higher than that of OPC at the same compressive strength, while the elastic modulus of TGC was 25.8% lower than that of OPC. Appropriate prediction models with the R² of 0.945 and 0.987 for predicting flexural tensile strength and elastic modulus using compressive strength, respectively, were proposed. Fitting models, considering the effects of AC and AAM, were also proposed to predict the mechanical properties of TGC.

关键词： Ternary Geopolymer Concrete (TGC) alkaline activator modulus alkali content mechanical properties assessment

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Influence of surface cracking, anchor head profile, and anchor head size on cast-in headed anchors in geopolymer

《结构与土木工程前沿（英文）》页码 1163-1187 doi: 10.1007/s11709-023-0987-5

摘要： In this study, the concrete cone capacity, concrete cone angle, and load–displacement response of cast-in headed anchors in geopolymer concrete are explored using numerical analyses. The concrete damaged plasticity (CDP) model in ABAQUS is used to simulate the behavior of concrete substrates. The tensile behavior of anchors in geopolymer concrete is compared with that in normal concrete as well as that predicted by the linear fracture mechanics (LFM) and concrete capacity design (CCD) models. The results show that the capacity of the anchors in geopolymer concrete is 30%–40% lower than that in normal concrete. The results also indicate that the CCD model overestimates the capacity of the anchors in geopolymer concrete, whereas the LFM model provides a much more conservative prediction. The extent of the difference between the predictions by the numerical analysis and those of the above prediction models depends on the effective embedment depth of the anchor and the anchor head size. The influence of concrete surface cracking on the capacity of the anchor is shown to depend on the location of the crack and the effective embedment depth. The influence of the anchor head profile on the tensile capacity of the anchors is found to be insignificant.

关键词： cast-in anchor concrete cone capacity geopolymer concrete head size surface crack anchor profile

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Printability and hardening performance of three-dimensionally-printed geopolymer based on lunar regolith

《结构与土木工程前沿（英文）》 doi: 10.1007/s11709-023-0003-0

摘要： Using an in situ lunar regolith as a construction material in combination with 3D printing not only reduces the weight of materials carried from the Earth but also improves the automation of lunar infrastructure construction. This study aims to improve the printability of a geopolymer based on a BH-1 lunar regolith simulant, including the extrudability, open time, and buildability, by controlling the temperature and adding admixtures. Rheological parameters were used to represent printability with different water-to-binder ratios, printing temperatures, and contents of additives. The mechanical properties of the hardening geopolymer with different filling paths and loading directions were tested. The results show that heating the printed filaments with a water-to-binder ratio of 0.32 at 80 °C can adjust the printability without adding any additive, which can reduce the construction cost of lunar infrastructure. The printability of the BH-1 geopolymer can also be improved by adding 0.3% Attagel-50 and 0.5% polypropylene fiber by mass at a temperature of 20 °C to cope with the changeable environmental conditions on the Moon. After curing under a simulated lunar environment, the 72-h flexural and compressive strengths of the geopolymer specimens reach 4.1 and 48.1 MPa, respectively, which are promising considering that the acceleration of gravity on the Moon is 1/6 of that on the Earth.

关键词： geopolymer lunar regolith simulant 3D printing rheology printability

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Resistance to acid degradation, sorptivity, and setting time of geopolymer mortars

Osama A MOHAMED; Rania AL-KHATTAB; Waddah AL-HAWAT

《结构与土木工程前沿（英文）》 2022年第16卷第6期页码 781-791 doi: 10.1007/s11709-022-0862-9

摘要： Experimental evaluations were conducted to determine the water sorptivity, setting time, and resistance to a highly acidic environment, of mortar with alkali-activated ground granulated blast furnace slag (GBS) binder and also of combinations of fly ash and GBS binders. Binders were activated using mixtures of NaOH and Na₂SiO₃ solutions. The molarity of NaOH in the mixtures ranged from 10 mol·L⁻¹ to 16 mol·L⁻¹, and the Na₂SiO₃/NaOH ratio was varied from 1.5 to 2.5. Mortar samples were produced using three binder combinations: 1) GBS as the only binder; 2) blended binder with a slag-to-fly ash ratio of 3:1; and 3) mixed binder with 1:1 ratio of slag to fly ash. Mortar samples were mixed and cured at (22 ± 2) °C till the day of the test. The impact of activator solution alkalinity, activator ratio Na₂SiO₃/NaOH, GBS content on the rate of water absorption were evaluated. After 7, 28, and 90 d of immersion in a 10% sulfuric acid solution, the resistance of a geopolymer matrix to degradation was assessed by measuring the change in sample weight. The influence of solution alkalinity and relative fly ash content on setting times was investigated. Alkali-activated mortar with a slag-to-fly ash ratio of 3:1 had the least sorptivity compared to the two other binder combinations, at each curing age, and for mortars made with each of the NaOH alkaline activator concentrations. Mortar sorptivity decreased with age and sodium hydroxide concentrations, suggesting the production of geopolymerization products. No reduction in weight of sample occurred after immersion in the strong acid H₂SO₄ solution for three months, regardless of binder combination. This was due to the synthesis of hydration and geopolymerization products in the presence of curing water, which outweighed the degradation of the geopolymer matrix caused by sulfuric acid.

关键词： alkali-activated materials fly ash sorptivity durability of concrete sodium hydroxide sodium silicates reduction in CO₂ emissions sulfuric acid

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Immobilization of Cu

Lei ZHENG,Wei WANG,Wei QIAO,Yunchun SHI,Xiao LIU

《环境科学与工程前沿（英文）》 2015年第9卷第4期页码 642-648 doi: 10.1007/s11783-014-0707-4

摘要： The present research explored the application of geopolymerization for the immobilization and solidification of heavy metal added into metakaolinte. The compressive strength of geopolymers was controlled by the dosage of heavy metal cations, and geopolymers have a toleration limit for heavy metals. The influence of alkaline activator dosage and type on the heavy metal ion immobilization efficiency of metakaolinte-based geopolymer was investigated. A geopolymer with the highest heavy metal immobilization efficiency was identified to occur at an intermediate Na SiO dosage and the metal immobilization efficiency showed an orderly increase with the increasing Na dosage. Geopolymers with and without heavy metals were analyzed by the X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. No crystalline phase containing heavy metals was detected in geopolymers with heavy metal, suggesting that the crystalline phase containing heavy metals is not produced or most of the phases incorporating heavy metals are amorphous. FTIR spectroscopy showed that, with increasing heavy metal addition, an increase in peak intensity was observed, which was accompanied by a decrease in the peak.

关键词： geopolymer heavy metal immobilization solidification

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基于BH-1模拟月壤的低碱高强地聚合物的制备与表征 Article

周思齐, 鲁乘鸿, 朱兴一, 李峰

《工程（英文）》 2021年第7卷第11期页码 1631-1645 doi: 10.1016/j.eng.2020.10.016

摘要：

建设月球基地以支持月面科研任务和资源利用一直是各国研究人员的目标。使用月球材料进行原位资源利用制备建筑材料对于节省昂贵的太空运费具有重要意义。本文研制了一种新型模拟月壤，名为北航（BH）-1。通过X射线荧光光谱（XRF）、X射线衍射（XRD）、扫描电子显微镜（SEM）和反射光谱结果证实，BH-1 的化学矿物组成和微观结构与真实月壤非常相似。本研究还在模拟月球环境条件下合成了一种基于BH-1 模拟月壤的地聚合物，并研究了补充铝源对地聚合物强度的影响。测定了碱激发BH-1 浆体的流变性能。采用XRF、XRD、傅里叶红外光谱、SEM能谱分析和27Al 魔角旋转核磁共振分析对地聚合物进行表征。试验结果表明，BH-1 浆体的流变曲线符合Herschel-Bulkley 模型，表现为剪切变稀流体。添加铝源的BH-1 地聚合物与对照组相比，28 天抗压强度可提高100.8%。同时，产生单位强度所需的添加剂的质量降低，显著减少了从地球运输至月球用于地聚合物制备的材料质量，有望节约太空运输成本。微观实验分析表明，通过添加额外的铝源来改善BH-1 地聚合物的力学性能机理为：促进了硅氧基中铝原子基团对硅原子基团的取代作用，生成更致密的无定形凝胶结构。

关键词：深空探测月球基地地聚合物模拟月壤流变学

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Effects of seeding nucleation agent on geopolymerization process of fly-ash geopolymer

Lapyote PRASITTISOPIN, Issara SEREEWATTHANAWUT

《结构与土木工程前沿（英文）》 2018年第12卷第1期页码 16-25 doi: 10.1007/s11709-016-0373-7

摘要： Geopolymer, an inorganic aluminosilicate material activated by alkaline medium solution, can perform as an inorganic adhesive. The geopolymer technology has a viability to substitute traditional concrete made of portland cement (PC) because replacing PC with fly ash leads to reduced carbon dioxide emissions from cement productions and reduced materials cost. Although fly ash geopolymer stimulates sustainability, it is slow geopolymerization reaction poses a challenge for construction technology in term of practicality. The development of increasing geopolymerization reaction rate of the geopolymer is needed. ?The purpose of this study is to evaluate seeding nucleation agents (NA) of fly ash geopolymer that can accelerate polymerization reactions such that the geopolymer can be widely used in the construction industry. Results from the present study indicate that the use of NA (i.e., Ca(OH) ) can be potentially used to increase geopolymerization reaction rate and improve performance characteristics of the fly ash geopolymer product.

关键词： fly ash geopolymer nucleation agent portland cement replacement

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碱激发材料与普通硅酸盐水泥和混凝土的耐久性能比较 Review

王爱国, 郑毅, 张祖华, 刘开伟, 李燕, 石亮, 孙道胜

《工程（英文）》 2020年第6卷第6期页码 695-706 doi: 10.1016/j.eng.2019.08.019

摘要：

中国是世界上普通硅酸盐水泥（OPC）生产量和使用量最大的国家，基础设施建设的快速发展对混凝土材料提出了可持续发展的要求。碱激发材料（AAM）是一种新型节能环保建筑材料，具有广泛的应用前景。本文对比总结了AAM和OPC经硫酸盐侵蚀、酸侵蚀、碳化和氯离子渗透后的耐久性能，阐述了因硅铝质原材料不同和碱激发产物不同，导致AAM耐久性能表现出巨大差异的关系，并根据硅铝质原材料的钙（Ca）含量的高低，对比分析了无钙、低钙、高钙三种体系的AAM的性能劣化机理。尽管目前不同的研究对AAM的耐久性能和长期稳定性存在一定争议，并引起了相当的关注，但总体而言，AAM较OPC表现出了更好的耐久性能。

关键词：碱激发材料地聚合物耐久性能普通硅酸盐水泥劣化机理