scholarly journals Impact of Carbon Particle Character on the Cement-Based Composite Electrical Resistivity

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7505
Author(s):  
Vít Černý ◽  
Grigory Yakovlev ◽  
Rostislav Drochytka ◽  
Šimon Baránek ◽  
Lenka Mészárosová ◽  
...  
Keyword(s):  
Construction Industry ◽  
Fine Particles ◽  
Raw Materials ◽  
Carbon Particle ◽  
Silica Sand ◽  
Composite Matrix ◽  
Electrically Conductive ◽  
Conductive Fillers ◽  
Conductive Properties ◽  
The Impact

Electroconductive cement-based composites are modern materials that are commonly used in many industries such as the construction industry, among others. For example, these materials can be used as sensors for monitoring changes in construction, grounding suspension, and resistance heating materials, etc. The aim of the research presented in this article is to monitor the impact of carbon particle character on cement-based electroconductive composites. Four types of graphite were analyzed. Natural and synthetic types of graphite, with different particle sizes and one with improved electrically conductive properties, were tested. For the analysis of the electrical conductivity of powder raw materials, a new methodology was developed based on the experience of working with these materials. Various types of graphite were tested in pure cement paste (80% cement, 20% graphite) as well as in a composite matrix, which consisted of cement (16.8%), a mixture of silica sand 0–4 mm (56.4%), graphite filler (20.0%) ground limestone (6.7%) and super plasticizers (0.1%). The resistivity and physical-mechanical properties of the composite material were determined. Furthermore, the resistivity of the test samples was measured with a gradual decrease in saturation. It may be concluded that graphite fillers featuring very fine particles and high specific surface are most suitable and most effective for creating electrically conductive silicate composites. The amount, shape and, in particular, the fineness of the graphite filler particles thus creates suitable conditions for the creation of an integrated internal electricity-conductive network. In the case of the use of a coarse type of graphite or purely non-conductive fillers, the presence of an electrolyte, for example, in the form of water, is necessary to achieve a low resistivity. Samples with fine types of graphite fillers achieved stable resistivity values when the sample humidity changed. The addition of graphite fillers caused a large decrease in the strength of the samples.

Properties of Self-Compacting Geopolymer Concrete

2014 ◽  
Vol 803 ◽  
pp. 99-109 ◽  
Author(s):  
Muhd Fadhil Nuruddin ◽  
Fareed Ahmed Memon
Keyword(s):  
Construction Industry ◽  
Fossil Fuels ◽  
Negative Impact ◽  
Raw Materials ◽  
Construction Material ◽  
Construction Materials ◽  
Cement Production ◽  
Cement Manufacture ◽  
The Moment ◽  
The Impact

Concrete has been used in the construction industry since long times. It is probably the most widely used construction material in the world, largely due to the abundance of the raw materials for cement manufacture, low relative cost and the versatility and adaptability of concrete in forming various structural shapes. Massive production of concrete and the associated substantial manufacture of cement have however been observed to have a very negative impact. One of the biggest issues of growing concern at the moment faced by concrete industries is the impact of cement production on the environment. The production of cement not only depletes significant amount of natural resources, but also liberates a considerable amount of carbon dioxide (CO2) and other greenhouse gases into the atmosphere as a result of decarbonation of limestone and the combustion of fossil fuels. In addition, cement is among the most energy intensive construction materials, after aluminium and steel [1].

scholarly journals Investigation of heat loss of nodal connections of structures of energy -efficient "green" buildings

2021 ◽  
pp. 69-81
Author(s):  
Mark Berdnykov ◽  
Svetlana Shekhorkina ◽  
Marina Bordun
Keyword(s):  
Construction Industry ◽  
Energy Efficient ◽  
Carbon Dioxide Emissions ◽  
Raw Materials ◽  
Cost Effective ◽  
The United States ◽  
The European Union ◽  
Construction Operation ◽  
Traditional Construction ◽  
The Impact

The construction industry is the main consumer of natural resources, characterized by significant consumption of non-renewable resources and the impact on environmental pollution. Up to 50% of carbon dioxide emissions are accounted for by the construction industry. In addition, the main feature of the traditional construction industry is the overuse of energy, which affects the process of global warming and climate change. Energy is consumed in the extraction of raw materials, production and transportation of materials, in the process of construction, operation, repair and liquidation of buildings. Awareness of global environmental problems has led to a rethinking of the process of design, construction, operation and disposal of buildings in the European Union, the United States, Canada and others and the emergence of the concept of sustainable development and "green" construction. In this aspect, the main criteria for designing buildings are to minimize the impact on the environment, as well as reduce energy costs, reduce waste and harmful emissions. The solution of the above problems, taking into account national specifics, can be achieved by developing typical resource- and energy-efficient, cost-effective design solutions for load-bearing and enclosing elements and their joints using environmentally friendly materials of local origin (wood and materials based on it, clay materials, straw, reeds, etc.

scholarly journals A framework for life cycle assessment of concrete bridge decks

2021 ◽  
Author(s):  
Fouad Taki
Keyword(s):  
Life Cycle ◽  
Construction Industry ◽  
Bridge Deck ◽  
Raw Materials ◽  
Bridge Decks ◽  
Concrete Bridge ◽  
Lca Methodology ◽  
Concrete Bridge Decks ◽  
Concrete Bridge Deck ◽  
The Impact

he construction industry is the largest contributor to environmental loading, and while development will require more infrastructure to achieve its goals, this will require more construction and hence more pollution. In order to achieve a sustainable development, the construction industry has to reduce its environmental loading and consumption of energy and raw materials. The methodology of Life Cycle Assessment (LCA) can help in quantifying the cradle to grave impact of construction on the environment. This study was performed to develop a model that uses LCA methodology to estimate the environmental impact of concrete bridge decks in North America. The model traces the emissions during the life cycle of a concrete bridge deck, and then calculates the impact of these emissions on the environment. This study was performed to develop a model that uses LCA methodology to estimate the environmental impact of concrete bridge decks in North America. The model traces the emissions during the life cycle of a concrete bridge deck, and then calculates the impact of these emissions on the environment. The model also calculates the energy and raw materials that are consumed during the life cycle of a concrete bridge deck. This model can be used by designers to evaluate alternative bridge deck designs to select the environmentally sound one.

scholarly journals Recycled Mineral Raw Materials from Quarry Waste Using Hydrocyclones

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2047 ◽  
Author(s):  
Menéndez-Aguado L.D. ◽  
Marina Sánchez M. ◽  
Rodríguez M.A. ◽  
Coello Velázquez A.L. ◽  
Menéndez-Aguado J.M.
Keyword(s):  
Construction Industry ◽  
Circular Economy ◽  
Fine Particle ◽  
Fine Particles ◽  
Raw Materials ◽  
Direct Application ◽  
Raw Material ◽  
Mineral Raw Materials ◽  
Composition Of Minerals ◽  
Validation Tests

Mining activities in general, and quarrying processes in particular, generate huge amounts of tailings with a considerable presence of fine particles and with a variable composition of minerals, which could limit the direct application of those wastes. Under the paradigm of a circular economy, more effort has to be made to find adequate applications for those secondary raw materials. In this study, a process was proposed and tests were performed to valorise fine particle product as a raw material for the building and construction industry. Samples were taken from wastes in several aggregate production plants, being characterized and processed to remove the clayey components to obtain the cleanest quartz fraction. Then, different characterization and validation tests were carried out to analyse the application of these products as raw materials in the building and construction industry (cement and ceramics). Results showed that with no complex technologies, the tailings can be considered as a mineral raw material in different applications.

scholarly journals ASSESSMENT OF LOCAL CHROMITE SAND AS ‘GREEN’ REFRACTORY RAW MATERIALS FOR SAND CASTING APPLICATIONS IN A POST-PANDEMIC WORLD

2021 ◽  
Vol 32 (2) ◽  
pp. 65-74
Author(s):  
Jonathan Kabasele ◽  
Didier Nyembwe
Keyword(s):  
Fine Particles ◽  
Raw Materials ◽  
Health And Safety ◽  
Environmental Safety ◽  
Silica Sand ◽  
World Health ◽  
Metal Casting ◽  
Safety Measures ◽  
Foundry Industry ◽  
Moulding Material

In a post-pandemic world, health and environmental safety will become a more important issue than it was before the COVID-19 pandemic. Several fields of engineering, including the foundry industry, have already adopted health and safety measures in the workplace. The risk of pulmonary disease caused by the inhalation of fine particles of silica sand, the main moulding material used in the foundry industry, is rampant in that industry. In terms of environmental protection, the new regulatory restrictions on the disposal of used sand create the need for moulding aggregates to be more recyclable than silica. Chromite sand is an alternative refractory sand for metal casting applications, and is abundant in South Africa. The present study investigated whether this aggregate has better overall reusability than silica. The focus of this study is on the use of chromite sand in foundries as a contribution to improving health in the workplace and to reducing the environmental impact of foundry sand.

scholarly journals A framework for life cycle assessment of concrete bridge decks

2021 ◽  
Author(s):  
Fouad Taki
Keyword(s):  
Life Cycle ◽  
Construction Industry ◽  
Bridge Deck ◽  
Raw Materials ◽  
Bridge Decks ◽  
Concrete Bridge ◽  
Lca Methodology ◽  
Concrete Bridge Decks ◽  
Concrete Bridge Deck ◽  
The Impact

he construction industry is the largest contributor to environmental loading, and while development will require more infrastructure to achieve its goals, this will require more construction and hence more pollution. In order to achieve a sustainable development, the construction industry has to reduce its environmental loading and consumption of energy and raw materials. The methodology of Life Cycle Assessment (LCA) can help in quantifying the cradle to grave impact of construction on the environment. This study was performed to develop a model that uses LCA methodology to estimate the environmental impact of concrete bridge decks in North America. The model traces the emissions during the life cycle of a concrete bridge deck, and then calculates the impact of these emissions on the environment. This study was performed to develop a model that uses LCA methodology to estimate the environmental impact of concrete bridge decks in North America. The model traces the emissions during the life cycle of a concrete bridge deck, and then calculates the impact of these emissions on the environment. The model also calculates the energy and raw materials that are consumed during the life cycle of a concrete bridge deck. This model can be used by designers to evaluate alternative bridge deck designs to select the environmentally sound one.

scholarly journals Phosphogypsum Recycling: A Review of Environmental Issues, Current Trends, and Prospects

2021 ◽  
Vol 11 (4) ◽  
pp. 1575
Author(s):  
Yelizaveta Chernysh ◽  
Olena Yakhnenko ◽  
Viktoriia Chubur ◽  
Hynek Roubík
Keyword(s):  
Construction Industry ◽  
Raw Materials ◽  
Environmental Issues ◽  
Current Trends ◽  
Waste Dumps ◽  
Pollution Problem ◽  
Mobile Forms ◽  
Biochemical Approach ◽  
The Impact ◽  
And Storage

The problem of recycling and storage of phosphogypsum is topical for many countries around the world, as it is associated with environmental problems of pollution of water bodies, land, and atmosphere. Therefore, this paper analyzes the directions of phosphogypsum recycling and possible alternatives to its use. The main disadvantages of the existing methods of phosphogypsum processing were identified and trends in this waste management were also considered. Through the VOSviewer programme, a visualization of cluster interconnections was carried out in research publications of various fields of phosphogypsum utilization. Five clusters were formed: a red cluster—phosphogypsum recycling in the construction industry; green cluster—radiation pollution problem of phosphogypsum and phosphate fertilizers; yellow cluster—monitoring migration of phosphogypsum components in the ecosystem, with the mobile forms of heavy metals and their inflow into aquifers from phosphogypsum dumps; blue cluster—use of phosphogypsum in agriculture as an ameliorant and a component of fertilizer; and a purple cluster—the impact of phosphogypsum on microorganisms, particularly in bioremediation processes. Under the proposed integrated biochemical approach, the use of various bioprocesses of phosphogypsum recovery from waste dumps and implementation of new biotechnological solutions for processing phosphorus raw materials are presented.

THE IMPACT OF COVID-19 ON PROJECT DELIVERY: A PERSPECTIVE FROM THE CONSTRUCTION SECTOR IN THE UNITED ARAB EMIRATES

2020 ◽  
Vol 8 (5) ◽  
pp. 169-177
Author(s):  
Ahmad Ghandour
Keyword(s):  
Construction Industry ◽  
United Arab Emirates ◽  
Construction Projects ◽  
Raw Materials ◽  
Simple Random Sampling ◽  
Study Data ◽  
Project Delivery ◽  
Test Analysis ◽  
Paired Samples ◽  
The Impact

Purpose of study: The study aimed at establishing the implications of the COVID-19 pandemic on project delivery in the UAE with a significant focus on the construction industry. The study also sought to determine some of the negative implications of COVID-19 for the construction industry. Methodology: The within-subjects research design was employed in the study. Purposive and simple random sampling was used in the selection of the respondents. A total of 116 project managers in the construction industry were sampled for the study. Data was collecting using self-administered online questionnaires. The SPSS software was applied to analyze the collected data using the paired samples t-test analysis method to compare the means of the projected number of days taken to complete a project before and during the COVID-19 period. Main Findings: The study findings revealed that there is a statistically significant effect of the COVID-19 pandemic on the number of days taken to complete projects in the construction industry in the UAE. The findings of the study revealed that the pandemic resulted in a lack of access to raw materials and labor, thereby leading to a delay in the completion of projects. Application of the study: The revelation of the implications would inform the policy and decision-makers in the country to devise effective ways of addressing the challenges for the stability of the sector. The researcher recommends the same study to be replicated in other areas to identify the effects the pandemic has had on other industries. Another study should also be conducted on the effective strategies that should be adopted to address the effects caused by the COVID-19 pandemic on the construction industry in the UAE. Novelty/originality of the study: This is contemporary studies that deal with a current issue. The study concluded that the construction industry became a victim of COVID-19 to the extent that it has brought its projects to a halt and significantly eroded the market of its beneficiaries. Unlike other industries, construction projects cannot accommodate distance working but facing challenges making on-time delivery impossible and therefore construction industry is at risk.

scholarly journals Influence of Nanoparticles on Thermal and Electrical Conductivity of Composites

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 742 ◽  
Author(s):  
Divan Coetzee ◽  
Mohanapriya Venkataraman ◽  
Jiri Militky ◽  
Michal Petru
Keyword(s):  
Electrical Conductivity ◽  
Dimensional Stability ◽  
Environmental Concern ◽  
Phase Changes ◽  
Filler Material ◽  
Composite Matrix ◽  
Electrically Conductive ◽  
Toxicological Effects ◽  
Conductive Properties ◽  
Properties Of Composites

This review analyzes thermal and electrically conductive properties of composites and how they can be influenced by the addition of special nanoparticles. Composite functional characteristics—such as thermal and electrical conductivity, phase changes, dimensional stability, magnetization, and modulus increase—are tuned by selecting suitable nanoparticle filler material. The conductivity of composites can be related to the formation of conductive pathways as nanofiller materials form connections in the bulk of a composite matrix. With increasing use of nanomaterial containing composites and relatively little understanding of the toxicological effects thereof, adequate disposal and recyclability have become an increasing environmental concern.

The Impact of Terrorism on Construction Industry in Iraq

2015 ◽  
Vol 3 (2) ◽  
pp. 69-84
Author(s):  
Wadhah Amer Hatem ◽  
Samiaah M. Hassen Al-Tmeemy
Keyword(s):  
Construction Industry ◽  
Construction Projects ◽  
Historical Data ◽  
Terrorist Attacks ◽  
Construction Sector ◽  
Statistical Procedures ◽  
Qualitative Approaches ◽  
Suicide Attacks ◽  
The Face ◽  
The Impact

     Suicide attacks, bombings, explosions became the part of daily life in Iraq. Consequently, the threat of terrorism put the Iraqi construction sector in the face of unique and unusual challenges that not seen on other countries. These challenges can have extensive impact on construction projects. This paper seeks to examine the impact of the terrorist attacks on construction industry and determine the extent to which the impact of terrorism on construction projects in terms of cost, schedule, and quality. This study adapted quantitative and qualitative approaches to collect data using questionnaire survey and interviews, as well as historical data. The study focused on projects that have been the target of terrorist strikes in Diyala governorate. A variety of statistical procedures were employed in data analysis. The results revealed the extent to which terrorist attacks impact construction projects in terms of cost, time, and quality. The results of this study will enhance the awareness of all construction parties to the impact of the terrorist attacks against construction projects. Eventually, this can develop a risk management assessment and assist contractors to properly protect projects and buildings to minimize injuries and fatalities in the event of terrorism.

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