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Application of Iron Mine Waste Rock as an Innovative Cement Replacement Material in Mortar 1st

Application of Iron Mine Waste Rock as an Innovative Cement ...

1st International Conference on Net-Zero Built Environment: Innovations in Materials, Structures, and Management Practices, NTZR 2024

作者： Cezar, Bruna Figueiredo da Silva Magalhães, Margareth Pimenta, André Rocha Post-Graduate Program in Civil Engineering State University of Rio de Janeiro Rio de Janeiro Brazil Instrumentation and Computational Simulation Laboratory Federal Institute of Rio de Janeiro Rio de Janeiro Brazil

ISBN: (纸本)9783031696251

In recent decades, the world has experienced a surge in extreme environmental events, exacerbated by the ongoing impacts of climate change. Substantial research underscores the role of anthropogenic CO2 emissions as the primary driver behind climate change and global warming. Cement production, constituting roughly 7% of global anthropogenic CO2 emissions, stands as a significant contributor to this issue. Consequently, there has been a growing focus on mitigation strategies within the cement industry, particularly emphasizing the utilization of mineral admixtures. An innovative yet underexplored material for partial cement replacement is iron mining waste rock, a by-product of open-pit mining operations used to extract iron ore deposits. Unlike underground mining, open-pit methods generate larger volumes of waste rock, typically stored in substantial geotechnical structures like piles, pits, or dams. This study conducted physical–chemical, mineralogical, and morphological characterizations on iron mine waste rock. Subsequently, four mortar mixtures were formulated, integrating iron mine waste as a partial substitute for cement (up to 30% by mass), and compared against a reference mortar. The performance assessment encompassed evaluations of fresh mortar properties, compressive strength, and elastic modulus. Findings revealed that the waste rock demonstrates limited pozzolanic activity, primarily functioning as a filler, and its inclusion in mortar enhances the workability of the mixes. However, a marginal reduction in compressive strength (up to 15%) was observed in mortar mixtures where 30% of the cement was replaced by waste rock. © The Author(s) 2025.

关键词： Open pit mining

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STRUCTURAL ASSESSMENT OF COMPOSITE HIGHWAY BRIDGES CONSIDERING VEHICLE-BRIDGE DYNAMIC INTERACTION

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ce/papers 2024年第1-2期7卷 165-174页

作者： da Silva, Ana Célia Soares Alencar, Guilherme Santana da Silva, José Guilherme Santos Civil Engineering Post-graduate Program [PGECIV/UERJ Brazil Brazil Brazil

Over time, as the bridge deck pavement deterioration process increases, the calculated vertical translational displacements and stresses are higher. In this context, the chances of mechanical failure occurrence increase and may cause limitation in the service life of steel and composite (steel-concrete) bridges. Thus, the current work presents a methodology for fatigue analysis developed by the authors through the years. The methodology is devoted specifically for the assessment of composite bridges employing the hot-spot local S-N approach and a coupled vehicle-pavement-bridge system considering progressive pavement deterioration with stochastically generated roughness profiles. © 2024 Ernst & Sohn GmbH.

关键词： Deterioration

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INVESTIGATION OF FLEXURAL BEHAVIOUR OF STAINLESS STEEL CHANNEL SECTIONS

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ce/papers 2024年第1-2期7卷 240-249页

作者： de Lima, Cláucio Gonçalves Rodrigues, Monique Cordeiro Pereira, e Fernanda Lins Gonçalves PGECIV – Civil Engineering Post-Graduate Program UERJ – State University of Rio de Janeiro Brazil Structural Engineering Department UERJ – State University of Rio de Janeiro Brazil

In this paper, the design of austenitic stainless steel channel sections subjected to minor axis bending, specifically with tension in the web ("u" orientation) is analyzed. The values of moment resistance are predicted using Eurocode 3 criteria and the Continuous Strength Method (CSM), which are then compared with numerical models to assess effectiveness. The modeling is performed through ANSYS and calibrated with literature tests. It was found that Eurocode presents a considerable disparity in results, as well as an overly cautious response (on average, half the numerical load). The CSM reflects the performance more accurately but still with a certain level of conservatism (on average, around 35% lower). © 2024 Ernst & Sohn GmbH.

关键词： Codes (standards)

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Antioxidant system alterations and oxidative stress caused by polyfluoroalkyl substances (PFAS) in exposed biota: a review

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Science of the Total Environment 2025年 977卷 179395页

作者： Soares, Lorena Oliveira Souza de Araujo, Gabriel Farias Gomes, Thais Braga Júnior, Sidney Fernandes Sales Cuprys, Agnieszka Katarzyna Soares, Raquel Moraes Saggioro, Enrico Mendes Laboratory of Environmental Health Assessment and Promotion Oswaldo Cruz Institute Oswaldo Cruz Foundation Av. Brasil 4365 RJ Rio de Janeiro21045-900 Brazil Post-Graduate Program in Public Health and Environment Sergio Arouca National School of Public Health Oswaldo Cruz Foundation Av. Leopoldo Bulhões 1480 RJ Rio de Janeiro21041-210 Brazil Faculty of Science and Technology Norwegian University of Life Sciences P.O. Box 5003 Ås1432 Norway Post-Graduate Program in Environmental Technology and Water Resources Department of Civil and Environmental Engineering – FT University of Brasília Darcy Ribeiro Campus Via L3 Norte DF Brasília70910-900 Brazil

Contamination of aquatic and terrestrial organisms by Perfluoroalkyl substances (PFAS), emerging contaminants, is widespread, as these compounds are present in water, soil, air, and food, owing to their environmental persistence. PFAS exposure induces biochemical process alterations associated with the disruption of the antioxidant defense system in several species. This review aims to discuss how PFAS-induced antioxidant system alterations lead to changes in biochemical processes in different organisms exposed to these pollutants. This disruption, then leads to an imbalance in antioxidant defense systems, contributing to the formation of reactive oxidative species (ROS), which, in turn, can be exacerbate oxidative stress, induce cellular damage, enhance lipid peroxidation, destabilize lysosomal membranes, and cause genotoxic effects, ultimately compromising DNA integrity. In acute tests, PFAS have led to mortality, growth inhibition, diminished behavioral and locomotor abilities, and reproductive impairment. PFAS-induced effects differ with varying species or types of substances, and further bioaccumulation through food chains exacerbates environmental contamination, carrying considerable risks. These findings demonstrate the complex and enduring impact of PFAS on environmental health, emphasizing the importance of this review in corroborating studies on sub-lethal toxicity in exposed organisms and how these effects reflect on the environment. © 2025 Elsevier B.V.

关键词： Biotic

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Finite element analysis of walking vibration problems for tubular steel-concrete composite footbridges

Finite element analysis of walking vibration problems for tu...

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11th International Conference on Computational Structures Technology, CST 2012

作者： Debona, G.L. Santos Da Silva, J.G. Sieira, A.C.C.F. Da S. Vellasco, P.C.G. De Lima, L.R.O. Civil Engineering Post-Graduate Programme PGECIV Brazil Structural Engineering Department UERJ State University Rio de Janeiro Brazil

ISBN: (纸本)9781905088546

The main objective of this investigation is to present the finite element modelling of the dynamic behaviour of tubular composite (steel-concrete) footbridges subjected to human walking vibrations. The investigated structural system was based on a tubular composite (steel-concrete) footbridge, spanning 82.5 m. The structural model consists of tubular steel sections and a concrete slab. This investigation is carried out based on correlations between the experimental results related to the footbridge dynamic response and those obtained with finite element modelling. The finite element model enabled a complete dynamic evaluation of the tubular footbridge in terms of human comfort and its associated vibration serviceability limit states. The peak accelerations found in the present analysis indicated that the investigated tubular footbridge presented problems related with human comfort. Hence it was detected that this type of structure can reach high vibration levels that can compromise the footbridge user's comfort. © civil-Comp Press, 2012.

关键词： Structural dynamics

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Vibration analysis of tubular footbridges induced by human walking

Vibration analysis of tubular footbridges induced by human w...

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14th International Symposium on Tubular Structures, ISTS 2012

作者： Debona, G.L. Da Silva, J.G.S. Sieira, A.C.C.F. Da S. Vellasco, P.C.G. De Lima, L.R.O. Civil Engineering Post-Graduate Programme PGECIV State University of Rio de Janeiro UERJ Rio de Janeiro Brazil

ISBN: (纸本)9780415621373

The main objective of this investigation is to present the finite element modelling of the dynamic behaviour of tubular composite (steel-concrete) footbridges submitted to human walking vibrations. The investigated structural system was based on a tubular composite (steel-concrete) footbridge, spanning 82.5 m. The structural model consists of tubular steel sections and a concrete slab. This investigation is carried out based on correlations between the experimental results related to the footbridge dynamic response and those obtained with finite element modelling. The finite element model enabled a complete dynamic evaluation of the tubular footbridge in terms of human comfort and its associated vibration serviceability limit states. The peak accelerations found in the present analysis indicated that the investigated tubular footbridge presented problems related with human comfort. Hence it was detected that this type of structure can reach high vibration levels that can compromise the footbridge user's comfort. © 2012 Taylor & Francis Group, London.

关键词： Concrete slabs

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Influence of chord stresses on the strength of RHS joints 9

Influence of chord stresses on the strength of RHS joints

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9th International Conference on Advances in Steel Structures, ICASS 2018

作者： Mendes, Flávio F. de Lima, Luciano R.O. da Vellasco, Pedro C. G. S. Rodrigues, Monique C. Neves, Luis F.C. PGECIV - Civil Engineering Post-Graduate Program UERJ - State University of Rio de Janeiro Brazil Structural Engineering Department UERJ - State University of Rio de Janeiro Brazil INESCC Civil Engineering Department University of Coimbra Portugal

ISBN: (纸本)9889914093

Extensive work has been performed to address the technological and design issues of tubular joints in the last decades. Several international design codes and recommendations explicitly cover the design of tubular joints such as Eurocode 3, ISO14346 and NBR16239. Experimental results on the influence of the chord stresses over the brace load capacity have been published in the literature. These results showed that compressive chord stresses considerably reduce the joint resistance. However, very few studies indicated the same reduction in load carrying capacity for joints under the action of chord tensile forces. To investigate this influence, an experimental program comprising thirteen tests was carried out, i.e. tests without chord axial forces;tests with compressive chord forces;and other ones with tensile chord forces. The obtained results were compared to the design provisions. This assessment indicated that the results obtained for chords without axial forces and with compressive forces, in experiments were safe when compared to the values predicted by all the investigated standards. On the other hand, the results associated with cases with chord tension forces proved to be conservative. Copyright © 2018 by The Hong Kong Institute of Steel Construction.

关键词： Software testing

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Structural behaviour of T RHS joints subjected to chord axial force 15

Structural behaviour of T RHS joints subjected to chord axia...

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Proceedings of the 15th International Symposium on Tubular Structures, ISTS 2015

作者： Nizer, A. De Lima, L. Da S. Vellasco, P. De Andrade, S. Da S. Goulart, E. Da Silva, A.T. Da C. Neves, L.F. PGECIV – Civil Engineering Post-Graduate Program UERJ – State University of Rio de Janeiro Brazil Structural Engineering Department UERJ – State University of Rio de Janeiro Brazil INESCC Civil Engineering Department University of Coimbra Portugal

ISBN: (纸本)9781138028371

This paper presents an experimental and numerical analysis of the chord normal stresses influence on the "T" tubular joints behaviour. The experimental program consisted of six tests: two without chord axial forces;two with compressive chord forces;and the remaining two with tensile chord forces. These results were compared to numerical results obtained with the aid of the ANSYS 12.0 software, and to the design provisions present in the: Eurocode 3;NBR 16239:2013 Brazilian standard and ISO 14346. This assessment indicated that the results obtained for chords without axial forces and with compressive forces, in both experiments and numerical analyses, were safe when compared to the values predicted by all the investigated standards, where the best fit was obtained by ISO 14346. On the other hand, the results associated to cases with chord tension forces proved to be conservative. © 2015 Taylor & Francis Group, London.

关键词： Software testing

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Structural assessment of composite seam-welded rectangular hollow columns

Structural assessment of composite seam-welded rectangular h...

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作者： Castanheira, Deborah Souza De Lima, Luciano Rodrigues Ornelas Da Silva Vellasco, Pedro Colmar Gončalves Da Nóbrega Tavares, Maria Elizabeth PGECIV Civil Engineering Post Graduate Program UERJ State University of Rio de Janeiro Rio de Janeiro Brazil Structural Engineering Department UERJ State University of Rio de Janeiro Rio de Janeiro Brazil

Structural elements made of seam-welded hollow sections are considerably less expensive than their seamless equivalents. This is a strong incentive for their use, but the current steel design standards still contain recommendations for seam-welded hollow sections based on test results performed with sections produced using outdated steel grades and fabrication processes. These design procedures are even more conservative when applied to composite tubular seam-welded elements. This paper presents an experimental campaign performed to investigate the structural behaviour of steel- and concrete-filled composite columns made with seam-welded rectangular hollow profiles. The experiments involved columns with only steel sections, concrete-filled and concrete-filled plus additional reinforcing bars. The main aim of the tests was to identify the contribution of each component in the overall structural response. The results enable an evaluation of the design recommendations present in Eurocode 4 aiming to determine less conservative buckling curves to be used for the investigated composite columns made of seam-welded rectangular hollow sections.

关键词： Reinforced concrete

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Non-linear dynamic analysis of steel-concrete composite floors subjected to human rhythmic activities

Non-linear dynamic analysis of steel-concrete composite floo...

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11th International Conference on Computational Structures Technology, CST 2012

作者： Lopes, E.D.C. Gonçalves, S.G. Gaspar, C.M.R. Santos Da Silva, J.G. De Andrade, S.A.L. Civil Engineering Department Pontifical University Catholic of Rio de Janeiro PUC-Rio Brazil Civil Engineering Post-graduate Programme PGECIV Brazil Structural Engineering Department UERJ State University of Rio de Janeiro Brazil

ISBN: (纸本)9781905088546

The main objective of this paper is to investigate the influence of steel-concrete interaction degree (from total to various levels of partial interaction) over the nonlinear dynamic behaviour of composite floors when subjected to human rhythmic activities. The investigated structural model was based on a steel-concrete composite floor spanning 40m by 40m, with a total area of 1600m2. The structural system consisted of a typical composite floor of a commercial building. The peak accelerations found in the present analysis indicated that the investigated floor presented problems related with human comfort. Hence it was detected that this type of structure can reach high vibration levels that can compromise the user's comfort. © civil-Comp Press, 2012.

关键词： Floors

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