检索结果-内蒙古大学图书馆

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

来源：评论

学校读者我要写书评

暂无评论

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

Remote Sensing Applied to the Extraction of Road Geometric Features Based on Optimum Path Forest Classifiers, Northeastern Brazil

引用

Journal of Geographic Information System 2020年第1期12卷 15-44页

作者： Márcia Macedo Maria Maia Emilia Kohlman Rabbani Oswaldo Lima Neto Post-Graduate Program in Civil Engineering UFPE Pernambuco Brazil Post-Graduate Program in Civil Engineering UPE Pernambuco Brazil

One of the principal difficulties related to road safety management in Brazil is the lack of data on road projects, especially those on rural roads, which makes it difficult to use road safety studies and models from other countries as a reference. Updating road networks through the use of hyperspectral remote sensing images can be a good alternative. However, accurately recognizing and extracting hyperspectral images from roads has been recognized as a challenging task in the processing of hyperspectral data. In order to solve the aforementioned challenges, Hyperion hyperspectral images were combined with the Optimum Forest Path (OPF) algorithm for supervised classification of rural roads and the effectiveness of the OPF and SVM classifiers when applied to these areas was compared. Both classifiers produced reasonable results, however, the OPF algorithm outperformed SVM. The higher classification accuracy obtained by the OPF was mainly attributed to the ability to better distinguish between regions of exposed soil and unpaved roads.

关键词： Roads Multispectral Images Hyperspectral Images Optimum Path Forest Algorithm

来源：评论

学校读者我要写书评

暂无评论

INVESTIGATION OF FLEXURAL BEHAVIOUR OF STAINLESS STEEL CHANNEL SECTIONS

引用

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)

来源：评论

学校读者我要写书评

暂无评论

Effect of Method and Duration of Curing on the Compressive Strength of the Lime-Fly Ash Geopolymer Concrete 1

Effect of Method and Duration of Curing on the Compressive S...

引用

1st Progress in Science and Technology Research Symposium, PSTRS 2019

作者： Adam, Andi Arham Akifa, Sri Nur Siregar, Atur P.N. Mustofa Department of Civil Engineering Tadulako University Indonesia Post-Graduate Program Tadulako University Indonesia Department of Mechanical Engineering Tadulako University Indonesia

The use of lime to produce ambient cured Geopolymer concrete is one of a practical solution to avoid heat curing in the production of geopolymer concrete. The addition of lime in the geopolymer system will add another hardened mechanism, i.e. hydration in addition to condensation-polymerisation. This research aims to determine the influence of air and water curing on the strength of geopolymer concrete which uses class F fly ash and lime as raw materials. The geopolymer concrete was produced by varying the activator (sodium silicate and sodium hydroxide) with the variation of the activator to binder ratio of 0.45, 0.50, 0.55, and 0.60. Five per cent of the fly ash was replaced by slaked lime and the water added to the mix to maintain the ratio of water to solid (activator + binder) to 0.32. The test specimens were 100 mm dia x 200 mm height cylinder. Water-immersion curing was performed for 7, 14, and 21 days and the compressive strength test was done at 28 days. The results show that there is a difference in the curing process between the geopolymer concrete and the normal concrete. In the geopolymer concrete, there is a decrease in compressive strength if soaked for seven days and recovered with the increase in the age of immersion. Whereas for normal concrete, the compressive strength continues to increase with increasing age of immersion. © Published under licence by IOP Publishing Ltd.

关键词： Compressive strength

来源：评论

学校读者我要写书评

暂无评论

Relative importance of pathologies in the severity of facade degradation

引用

Journal of Building Pathology and Rehabilitation 2020年第1期5卷 1-10页

作者： Bauer, Elton Piazzarollo, Carla Bozzi de Souza, Jéssica Siqueira dos Santos, Danilo Gonçalves Post-Graduate Program in Structures and Civil Construction Civil and Environmental Engineering Department University of Brasília Campus Universitário Darcy Ribeiro Asa Norte Brasília DF Brazil

The facade is the main protective barrier against the atmospheric agents acting in a building. Many times, as a result of these agents, the facade manifests pathologies that lead to the loss of performance of the external wall claddings. This article aims to establish and score the importance of the pathologies involved in the cement mortars rendering. The probable causes and the influence on the performance decrease over time are analyzed. The methodology is based on the survey and mapping of the pathologies observed in field survey, correlating these pathologies with probable causes and implications for the system performance. Among the active pathologies, cracks had both a higher intensity of occurrence and a greater gravity compared to the others. Some pathologies, such as detachment and efflorescence, although of great importance in the degradation, are little observed in the studied buildings. As a result, is presented a scale of importance of pathologies, which has great application for the development of facade degradation models. © 2020, Springer Nature Switzerland AG.

关键词： Cement mortar Degradation External wall claddings Facades Pathologies

来源：评论

学校读者我要写书评

暂无评论

GIS-Based Methodology for Crash Prediction on Single-Lane Rural Highways

引用

Journal of Geographic Information System 2021年第2期13卷 98-121页

作者： Márcia Macedo Emilia Kohlman Rabbani Maria Maia Marlos Macedo Bianca Ferreira Post-Graduate Program in Civil Engineering UPE Recife Brazil Post-Graduate Program in Systems Engineering UPE Recife Brazil Graduate Program in Architecture and Urban Planning UNICAP Recife Brazil

Due to the need to update the current guidelines for highway design to focus on safety, this study sought to build an accident prediction model using a Geographic Information System (GIS) for single-lane rural highways, with a minimum of statistically significant variables, adequate to the Brazilian reality, and improve accident prediction for places with similar characteristics. A database was created to associate the accident records with the geometric parameters of the highway and to fill in the gaps left by the absence of geometric highway plans through geometric reconstitution or semi-automatic extraction of highways using satellite images. The Generalized Estimating Equation (GEE) method was applied to estimate the coefficients of the model, assuming negative distribution of the binomial error for the count of observed accidents. The accident frequency and annual average daily traffic (AADT) were analyzed, along with the spatial and geometric characteristics of 215 km of federal single-lane rural highways between 2007 and 2016. The GEE procedure was applied to two models having three variations of distinct homogeneous segmentation, two based on segments and one based on the kernel density estimator. To assess the effect of constant traffic, two more variations of the models using AADT as an offset variable were considered. The predominant correlation structure in the models was the exchangeable. The principal contributing factors for the occurrence of collisions were the radius of the horizontal curve, the grade, segment length, and the AADT. The study produced clear indicators for the design parameters of roadways that influence the safety performance of rural highways.

关键词： Roads GEE Single-Lane Rural Highways GIS Crash Prediction

来源：评论

学校读者我要写书评

暂无评论

The Effect of EPS Addition to Soil Stabilized with Fly Ash as Lightweight Fill Materials for Embankment Construction 1

The Effect of EPS Addition to Soil Stabilized with Fly Ash a...

引用

2018 1st Workshop on engineering, Education, Applied Sciences, and Technology, WEAST 2018

作者： Syahril Somantri, Andri Krisnandi Febriansya, Aditia Civil Engineering Department Politeknik Negeri Bandung Bandung Indonesia Post-Graduate Stud. of Infrastructure Engineering Study Program Applied Master Program Politeknik Negeri Bandung Bandung Indonesia

Design and construction of road embankment presents several challenges, including the possibility of bearing capacity failure, large total settlement, differential settlement, and slope instability, which may result from the weight of the embankment construction itself, and/or weak foundation. A number of techniques have been developed and can be used to overcome these problems, one of them is by modifying the weight of the embankment itself with the use of lightweight materials, such as soil-EPS mixture. The use of soil-EPS mixture as lightweight material provides several advantages, among which can achieve the same volume or elevation requirement with a significantly lighter weight compared to ordinary materials, improving slope stability, embankment over high compressibility soil, and to reduce soil pressure to soil retaining structures, abutment or bridge pillar. Fly ash also added to act as binder to increase shear strength of mixture. The result of the compaction test shows that the addition of a small amount of EPS to the mixture can significantly reduce the maximum dry density of the mixture. Triaxial UU and UCS test results show a reduction in mixture strength as EPS contents increase, but due to the presence of fly ash increases the strength of mixture as the number of day increases, so that the use of lightweight materials has the potential to be one of soil improvement solutions. © Published under licence by IOP Publishing Ltd.

关键词： Mixtures

来源：评论

学校读者我要写书评

暂无评论

Application of the Updated PSHA on the Stability Analysis of the Meninting Diversion-Spillway Tunnel in Lombok Island—Indonesia 5th

Application of the Updated PSHA on the Stability Analysis of...

引用

5th International Conference on Rehabilitation and Maintenance in civil engineering, ICRMCE 2021

作者： Agustawijaya, Didi S. Marlaningtyas, Ria R. Murtiadi, Suryawan Wahyudi, Mudji Muhajirah Hartana Agustawijaya, Ausa R. Post-Graduate Study Program Department of Civil Engineering University of Mataram Mataram Indonesia Geo-Engineering Research Group Department of Civil Engineering University of Mataram Mataram Indonesia Department of Geomatics Engineering ITS Surabaya Indonesia

ISBN: (纸本)9789811693472

The Meninting diversion-spillway tunnel is a part of the Meninting dam project located in West Lombok District. The construction commenced in 2017;then, a series of severe Lombok earthquakes halted the construction of the tunnel for a while in 2018, where some landslides occurred around the site. This possibly caused rock masses around the tunnel to be sheared off during the earthquake events. Updated probability seismic hazard analysis shows increased seismic parameters, including peak ground, short spectrum and long spectrum accelerations, which then resulted in increased stresses around the tunnel. Thus, the stability of the tunnel decreased in terms of its factors of safety. Although, the overall factor of safety was about 2.5, the tunnel was still stable in current conditions;the tunnel certainly requires more stability improvements to face possible similar severe earthquakes in future. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Earthquakes

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：