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Journal of Southeast University(English Edition) 2018年第3期34卷 371-376页

作者： Mi Renjie Pan Ganghua Li Yang Lu Xiaojun z School of Materials Science and Engineering Southeast UniversityNanjing 211189China jiangsu Key Lab of Construction Materials Southeast UniversityNanjing 211189China Jiangsu Collaborative Innovation Center Southeast UniversityNanjing 211189China jiangsu Zhenjiang Research Institute of Building Science Group Co. LtdZhenjiang 212004China

In order to expand the engineering application of recycle aggregate mortars （RAM） with aggregates from demolished concretes, the models for the properties of RAM and the replacement rate of these recycled fine aggregates were proposed. First, different kinds of mathematical models for the basic properties （compressive strength, water retention rate, and consistency loss） of RAM with two kinds of admixtures, thickening powders （TP） and self-made powdery admixtures （SSCT） designed for RAM, and the replacement rates were established, while the average relative errors and relative standard errors of these models were calculated. Additionally, the models and their error analyses for the curves of drying shrinkage and curing time of RAM ＋ SSCT at different replacement rates were put forward. The results show that polynomial functions should be used to calculate the basic properties of RAM ＋ TP and RAM ＋ SSCT at different replacement rates. In addition, polynonfial functions are the most optimal models for the sharp shrinkage sections in the curves of drying shrinkage-curing time of RAM ＋ SSCT, while exponential functions should be used as the models for the slow shrinkage sections and steady shrinkage sections.

关键词： demolished concrete recycled fine aggregates admixtures recycled aggregate mortars mathematical model

Hydration Properties of Calcined Clay Pozzolan and Limestone Mineral admixtures in Binary and Ternary Cements

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Journal of Physical Science and Application 2014年第5期4卷 323-327页

作者： Eugene Atiemo Charles Kwame Kankam Francis Momade Kwabena Appiah Boakye CSIR-Building and Road Research Institute UST Box 40 Kumasi Ghana Kwame Nkrumah University of Science and Technology College of Engineering Kumasi Ghana

This paper investigates the properties of hydrated binary and ternary blended cements using limestone and calcined clay pozzolan as supplementary cementitious materials. The blended cements were hydrated and their phase compositions were evaluated by thermogravimetric and powder X-ray diffraction at 28 days. The morphology of the samples was also determined. The water demand, setting time, compressive and flexural strengths of mortar and concrete samples were determined up to 365 days. The study concluded that the portlandite [Ca（OH）2] content was considerably reduced whilst ettfingite formation were enhanced as a result of admixture reactions. The water demand and setting times of blended cements were lower than OPC with 5% admixture content but higher with increasing content. The mechanical test results also showed that Class 42.5N and 32.5R cements can be produced from the binary and ternary blends containing up to 10% and 20% admixtures, respectively.

关键词： limestone calcined clay pozzolan supplementary cementitious materials admixtures portlandite ettringite strength.

Effects of admixtures on the Anti-oxidation Property of MgO/Si_3N_4 Composite Refractory

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China's Refractories 2003年第1期12卷 12-16页

作者： WANGLinjun TIANShunzhi 等 InorganicNon－metallicMaterialsInstitute UniversityofScienceandTechnologyBeijingBeijing100083China JiaozuoBiggerRefractoriesCo.Ltd JiaozuoHenan454171China

The effect of the admixtures of Al and Si metals and B4 C and MgAlON compounds on the oxidation of MgO/ Si3N4 composite refractory has been studied, which is a promising carbon free refractory for steel-making application . The four kinds of admixtures can be used as anti-oxi-dants for Si3N4, but the mixture of Al and Si achieved the best result. The mixture can not only play the role as anti-oxidant, but also assist the sintering process and help form dense sintering layer, improving the property of the composite.

关键词： admixtures Magnesia Silicon nitride Composite refractory Oxidation resistance

Exploring the potential of olivine-containing copper-nickel slag for carbon dioxide mineralization in cementitious materials

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 562-573页

作者： Qianqian Wang Zequn Yao Lijie Guo Xiaodong Shen College of Materials Science and Engineering Nanjing Tech UniversityNanjing 211816China State Key Laboratory of Materials-Oriented Chemical Engineering Nanjing 211816China BGRIMM Technology Group Beijing 100160China

Water-quenched copper-nickel metallurgical slag enriched with olivine minerals exhibits promising potential for the production of CO_(2)-mineralized cementitious *** this work,copper-nickel slag-based cementitious material(CNCM)was synthesized by using different chemical activation methods to enhance its hydration reactivity and CO_(2) mineralization *** water curing ages and carbonation conditions were explored related to their carbonation and mechanical properties ***,thermogravimetry differential scanning calorimetry and X-ray diffraction methods were applied to evaluate the CO_(2) adsorption amount and carbonation products of *** development of carbonated CNCM blocks was examined by backscattered electron imaging(BSE)with energy-dispersive X-ray *** showed that among the studied samples,the CNCM sample that was subjected to water curing for 3 d exhibited the highest CO_(2) sequestration amount of 8.51wt%at 80℃and 72 h while presenting the compressive strength of 39.07 *** result indicated that 1 t of this CNCM can sequester 85.1 kg of CO_(2) and exhibit high compressive *** the addition of citric acid did not improve strength development,it was beneficial to increase the CO_(2) diffusion and adsorption amount under the same carbonation conditions from BSE *** work provides guidance for synthesizing CO_(2)-mineralized cementitious materials using large amounts of metallurgical slags containing olivine minerals.

关键词： copper-nickel slag fayalite CO_(2)sequestration cementitious material admixtures carbonation conditions

Effects of microfine aggregate in manufactured sand on bleeding and plastic shrinkage cracking of concrete

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Frontiers of Structural and Civil Engineering 2022年第11期16卷 1453-1473页

作者： Branavan ARULMOLY Chaminda KONTHESINGHA Anura NANAYAKKARA Department of Civil Engineering University of Sri JayewardenepuraMount Lavinia 10370Sri Lanka Department of Civil Engineering University of MoratuwaMoratuwa 10400Sri Lanka

Construction industries have started to utilize manufactured sand(MS)as an effective alternative for river sand in ***-grade parent rocks are crushed to obtain MS,which also produces a considerable amount of microfine aggregate(MFA).The higher percentage of MFA could lead to both positive and negative effects on the performance of cement-based *** research was done to examine the influence of varying MFA levels,specifically 0%,3%,6%,9%,and 12%(by weight)as the partial replacements of MS on bleeding and plastic shrinkage cracking of *** addition to the varying MFA levels,some concrete mixes also included fly ash(FA)and superplasticizer to investigate the effect of free-water content in the *** bleeding test data were taken as on-site measurements,while the cracks from the plastic shrinkage cracking test were evaluated using an image processing *** results concluded that the MFA replacements and the effective water-to-cement ratio have a significant effect on the selected concrete *** the increasing replacement levels,cumulative bleeding and crack initiation life gradually decreased,while a progressive increase was observed for crack width,crack length,and crack area.

关键词： manufactured sand fresh concrete microfines admixtures shrinkage cracking

Immobilization of Co(Ⅱ) Ions in Cement Pastes and Their Effects on the Hydration Characteristics

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Journal of Materials Science & Technology 2011年第1期27卷 74-80页

作者： Eisa Hekal Essam Kishar Wafaa Hegazi Maha Mohamed Chemistry Department Faculty of ScienceAin Shams University Chemistry Department Women s College for ArtsScience and EducationAin Shams University

The immobilization of Co（Ⅱ） in various cement matrices was investigated by using the solidification/stabilization（S/S） *** different cement pastes used in this study were ordinary Portland cement in absence and presence of water reducing-and water repelling-admixtures as well as blended cement with *** ratios of Co（Ⅱ） were used（0.5% and 1.0% by weight of the solid binder）.The hydration characteristics of the used cement pastes were tested via the determination of the combined water content,phase composition and compressive strength at different time intervals up to 180 *** degree of immobilization of the added heavy metal ions was evaluated by determining the leached ion concentration after time intervals extended up to 180 *** leachability experiments were carried out by using two modes：the static and the semi-dynamic leaching *** was noticed that the concentration of the leached Co2＋ ions in the static mode of leachability was lower than the solubility of its hydroxide in all the investigated cement pastes.

关键词： Hydration characteristic of cement admixtures Immobilization Heavy metals

Effect of Straw Mixing Amount on Mechanical Properties of Admixture-adding Hollow Block

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Journal of Wuhan University of Technology(Materials Science) 2013年第3期28卷 508-513页

作者：刘军 ZHOU Honghong OUYANG Peng School of Materials Science and Engineering Shenyang Ligong University School of Materials Science and Engineering Shenyang Jianzhu University School of Management Shenyang Urban Construction College

The bonding mechanism between straw and concrete was analyzed through testing the compressive strength and flexural strength of hollow block, with different straw amount and different dosage and types of admixtures. The test results show that the mechanical properties of hollow blocks reduced after adding straws, and the more straws was added, the more hollow block density decreased. But adding A12（SO4）3 and CaC12 could improve the dense degree between rice straw and concrete. And when the proportion of straw mixing amount was 10%, the flexural strength of the early strength agent （2% A12（SO4）3, CaC12） added hollow block reached as maximal as 3.1 MPa, while the compressive strength was 9.1 MPa, consisting with the strength grade of common concrete hollow block MU7.5.

关键词： straws admixtures mixing amount hollow block

A Blended Cement Containing Blast Furnace Slag and Phosphorous Slag

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Journal of Wuhan University of Technology(Materials Science) 2002年第2期17卷 62-65页

作者：李东旭 College of Materials Nanjing University of Technology Nanjing China

Blended cement containing blast furnace slag (BFS) and phosphorous slag( PS) is a new kind of cement. The total content of blended materials could increase if two additives were used. Using the same admixtures , the properties of the blended cement with 70% additives could reach the standard of 525-grade slag cement according to GB. The strength of cement with 80% additives could reach the standard of 425-grade slag cement. The tests of strength, pore structure, hydration products, inhibiting alkali-aggregate reaction, resistance to sulfate corrosion of BFS-PSC were performed.

关键词： blended cement blast furnace slag phosphorous slag admixtures alkali-aggregate reaction sulfate corrosion

Studies on Characteristics, Applications and Strength Improvement of Marine Clay: A Review

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Journal of Geoscience and Environment Protection 2019年第1期7卷 93-106页

作者： R. Saisubramanian V. Murugaiyan T. Sundararajan Department of Civil Engineering Pondicherry Engineering College Puducherry India

Strength assessment and improvement of strength parameters are essential to design the foundation in clay and marine clay. Several studies have been made in this aspect. Marine clay is also a potential material for use as liner material to contain landfill leach ate. The applications include use of marine clay for transforming waste into light weight aggregates and thus create better environment. The physical parameters such as Atterberg limits, California Bearing Ratio (CBR) value, dry density, specific gravity, free swell, chemical properties such as pH value, cation exchange capacity, organic matter content, calcium carbonate, and mineralogical composition using X-ray diffraction analysis are studied. The consolidation characteristics, determination of strength improvement strategies using admixtures at different proportions are frequently adopted. Commonly used admixtures are lime, limes mixed with cement, coir, shredded plastics. The consolidation studies are very vital and play an important role.

关键词： Marine clay Consolidation Characteristics admixtures Aggregates Land Fill

A Survey of High Performance Concrete Developments in Civil Engineering Field

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Open Journal of Civil Engineering 2013年第2期3卷 69-79页

作者： Vatsal Patel Niraj Shah C. S. Patel Institute of Engineering & Technology Charotar University of Science and Technology Changa India G. H. Patel College of Engineering &Technology Gujarat Technological University Ahmedabad India

High Performance concrete (HPC) has received increased attention in the development of infrastructure Viz., Buildings, Industrial Structures, Hydraulic Structures, Bridges and Highways etc. leading to utilization of large quantity of concrete. This paper presents a comprehensive coverage of High Performance concrete developments in civil engineering field. It highlights the High Performance concrete features and requirements over conventional concrete. Furthermore, recent trends with regard to High Performance Concrete development in this area are explored. This paper also includes effect of Mineral and Chemical admixtures used to improve performance of concrete.

关键词： Chemical admixtures Conventional Concrete High Performance Concrete Mineral admixtures