CEMENT Pub Date : 2024-01-17 DOI: 10.1016/j.cement.2024.100091

Vineet Shah

{"title":"Performance evaluation of carbonated cement paste derived from hydrated Portland cement based binders as supplementary cementitious material","authors":"Vineet Shah","doi":"10.1016/j.cement.2024.100091","DOIUrl":"https://doi.org/10.1016/j.cement.2024.100091","url":null,"abstract":"<div><p>The production of concrete has gone up from 2.3 billion m<sup>3</sup> in 2002 to 14 billion m<sup>3</sup> in 2020. At the same time, the amount of construction and demolition waste generated annually has reached levels of 3 billion tons, with concrete rubble making up a major portion of it. This study investigates the performance of carbonated fines derived from hydrated cement paste of different binders. Four cement paste blends, containing Portland cement (PC) and blends of Portland cement with fly ash (FA30), perlite (PL30) and metakaolin (MK30) at a 30 % cement replacement level, were cured for 90 days prior to subjecting them to a carbonation reaction. The R<sup>3</sup> test gauged pozzolanic reactivity, while calorimetry, XRD, and TGA studied hydration characteristics. Compressive strength of mortar samples prepared using the same binder composition as paste was also measured at different ages. Carbonated fines exhibited notable pozzolanic activity compared to waste hydrated cement paste. The reactivity of carbonated fines derived from different binders were similar, however slightly higher reactivity was measured for fines comprising of reactive SCM in the precursor material (hydrated paste). Mixes with carbonated fines demonstrated enhanced kinetics, exhibiting over 25 % higher compressive strength at 3 and 7 days compared to the fly ash control mix. Similar compressive strength characteristics were observed in mortar mixes with different carbonated fines, indicating a limited impact of the various binder types from which the fines originated.</p></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"15 ","pages":"Article 100091"},"PeriodicalIF":0.0,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S266654922400001X/pdfft?md5=11bac3d514ac9d5c852eb24f0b260128&pid=1-s2.0-S266654922400001X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139494204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Moisture in concrete and its influence on the durability 混凝土中的水分及其对耐久性的影响

CEMENT Pub Date : 2023-12-01 DOI: 10.1016/j.cement.2023.100087

Ueli M. Angst , Mette Geiker

引用次数: 0

Multiscale performance and environmental impact assessment of slag and Portland blended cement for optimum carbonation curing 针对最佳碳化固化的矿渣和硅酸盐混合水泥的多尺度性能和环境影响评估

CEMENT Pub Date : 2023-12-01 DOI: 10.1016/j.cement.2023.100088

Rakibul I. Khan , Muhammad Intesarul Haque , Adhora Tahsin , Warda Ashraf

{"title":"Multiscale performance and environmental impact assessment of slag and Portland blended cement for optimum carbonation curing","authors":"Rakibul I. Khan , Muhammad Intesarul Haque , Adhora Tahsin , Warda Ashraf","doi":"10.1016/j.cement.2023.100088","DOIUrl":"10.1016/j.cement.2023.100088","url":null,"abstract":"<div><p>This article presents an investigation into the potential use of ground granulated blast-furnace slag (addressed as Slag cement or ‘SC’) as a replacement to Ordinary Portland Cement (OPC) in hybrid (carbonation and hydration) cured cement-based materials. To investigate the effects of carbonation on mechanical performances and microstructures, 0 %–100 % OPC was replaced with slag cement (SC). Thermogravimetric analysis (TGA) and Fourier transformed infrared (FTIR) spectra were utilized to investigate the carbonation reaction extent, rate, and microstructural phase formations. Slag cement was found to improve the efficiency and rate of carbonation. This study revealed that a minimum of 72 h of carbonation in a CO<sub>2</sub>-containing environment yields better mechanical performance compared to the traditional curing method. Specifically, the incorporation of 72 h of carbonation curing was observed to increase the strength of concrete up to 30 % after 28 days of total curing duration (carbonation and hydration). The chloride permeability of the carbonation cured samples was observed to reduce by 80 % due to the addition of SC. Finally, it was observed that, the carbonated concrete sample with slag has nearly 60 % lower global warming potential compared to the carbonated and non-carbonated concrete sample with 100 % OPC binder.</p></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"14 ","pages":"Article 100088"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666549223000348/pdfft?md5=43acf1ddecbf514a170eb40b35f27fce&pid=1-s2.0-S2666549223000348-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138627635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Assessing regional variability in chemical composition and pozzolanic reactivity of corn stover ash in the United States 评估美国玉米秸秆灰化学成分和火山灰反应性的区域变异性

CEMENT Pub Date : 2023-09-08 DOI: 10.1016/j.cement.2023.100086

Mahmoud Shakouri , Jiong Hu , Cody Stolle

引用次数: 0

Early age reaction of slag in composite cement: Impact of sulphates and calcite 矿渣在复合水泥中的早期反应：硫酸盐和方解石的影响

CEMENT Pub Date : 2023-09-07 DOI: 10.1016/j.cement.2023.100085

Sam Adu-Amankwah , Leon Black , Liu Xianfeng , Pengkun Hou , Maciej Zajac

{"title":"Early age reaction of slag in composite cement: Impact of sulphates and calcite","authors":"Sam Adu-Amankwah , Leon Black , Liu Xianfeng , Pengkun Hou , Maciej Zajac","doi":"10.1016/j.cement.2023.100085","DOIUrl":"https://doi.org/10.1016/j.cement.2023.100085","url":null,"abstract":"<div><p>Ground granulated blast furnace slag (GGBS) is an important supplementary cementitious material (SCM) for producing low carbon and durable concrete. There are however questions around the early age reactivity of GGBS and the factors that influence this. To elucidate the fundamental mechanisms controlling the early age reactivity and particularly the influence of anionic species, simplified systems comprising GGBS and calcium hydroxide were examined in the presence of limestone, anhydrite, or both at 4:1 SCM-to-activator ratio. Limestone and GGBS were considered as SCMs, but calcium hydroxide and anhydrite were considered as activators. Multiple techniques, including isothermal calorimetry, thermogravimetry, X-ray diffraction, electron microscopy, mass balance calculation and mercury intrusion porosimetry were used to study hydration and microstructure. The results show that GGBS hydration commences immediately in the alkaline media provided by calcium hydroxide. Sulphates and limestone influence hydration through reactions with aluminates to form ettringite and carboaluminates, but prevalence of macro-capillary pores in sulphate containing binders sustains diffusion-controlled hydration. Consequently, optimization of the alumina to sulphate and carbonate ratios is essential for exploiting the pore solution and space filling effects in composite cements.</p></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"14 ","pages":"Article 100085"},"PeriodicalIF":0.0,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50194575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of alkali-silica reaction on mortars with alternative binder systems: Alkali activated Slags and Celitement 具有替代粘合剂体系的砂浆上的碱-二氧化硅反应的研究：碱活性矿渣和硅藻土

CEMENT Pub Date : 2023-09-01 DOI: 10.1016/j.cement.2023.100078

Julia T. Sonntag , Ravi A. Patel , David Alós Shepherd , Frank Dehn

引用次数: 0

Cold Water Extraction for determination of the free alkali metal content in blended cement pastes 冷水萃取法测定混合水泥浆中游离碱金属含量

CEMENT Pub Date : 2023-09-01 DOI: 10.1016/j.cement.2023.100079

Maxime Ranger , Marianne Tange Hasholt

引用次数: 0

Thermal activation of inert basaltic materials to create supplementary cementitious materials 惰性玄武岩材料的热活化以产生辅助胶凝材料

CEMENT Pub Date : 2023-09-01 DOI: 10.1016/j.cement.2023.100082

Ying Wang, Prannoy Suraneni

引用次数: 1

Sustainability of concretes with binary and ternary blended cements considering performance parameters 考虑性能参数的二元和三元混合水泥混凝土的可持续性

CEMENT Pub Date : 2023-09-01 DOI: 10.1016/j.cement.2023.100077

Gisela Cordoba , Manuel Barquero , Viviana Bonavetti , Edgardo F. Irassar

引用次数: 1

Effects of graphene nanoplatelets inclusion on microstructure and mechanical properties of alkali activated binders 石墨烯纳米片包裹体对碱活性粘结剂微观结构和力学性能的影响

CEMENT Pub Date : 2023-09-01 DOI: 10.1016/j.cement.2023.100080

Jarvis Devon, Emily Hacking, Kyra Wilson, Monica F. Craciun, Raffaele Vinai

{"title":"Effects of graphene nanoplatelets inclusion on microstructure and mechanical properties of alkali activated binders","authors":"Jarvis Devon, Emily Hacking, Kyra Wilson, Monica F. Craciun, Raffaele Vinai","doi":"10.1016/j.cement.2023.100080","DOIUrl":"https://doi.org/10.1016/j.cement.2023.100080","url":null,"abstract":"<div><p>This paper presents a study investigating for the first time the effects of the inclusion of graphene nanoplatelets (GNPs) on the mechanical and microstructural properties of alkali activated binders produced with fly ash and slag and using superplasticizer for the GNPs dispersion in the mixing water. Compressive strength and water absorption of mortar cubes, flexural strength of mortar beams, X-ray computer tomography scanning and mercury intrusion porosimetry, Fourier transform infrared spectroscopy, scanning electron microscopy with Energy Dispersive X-Ray Spectroscopy, and X-ray diffraction, were carried out on samples cured either at room temperature or at 40 °C. Results showed that the inclusion of GNPs at a dosage of 0.05% provided a considerable increase in compressive strength at both curing conditions. Microstructural observations suggested that the presence of GNPs improved the formation of hydrated gel, and the research demonstrated through porosity measurements the shift from the capillary to the gel pore region due to the inclusion of GNPs. This study represents a step forward in understanding the effects of GNPs inclusion on alkali activated binder microstructure.</p></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"13 ","pages":"Article 100080"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50191468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

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