scholarly journals Eco-efficient steel slag concretes: an alternative to achieve circular economy

2022 ◽  
Vol 15 (2) ◽  
Author(s):  
Laís Cristina Barbosa Costa ◽  
Marcela Aguiar Nogueira ◽  
Larissa Caroline Ferreira ◽  
Fernanda Pereira da Fonseca Elói ◽  
José Maria Franco de Carvalho ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Circular Economy ◽  
Lower Cost ◽  
Steel Slag ◽  
Cost Assessment ◽  
Sustainable Solutions ◽  
Concrete Production ◽  
Natural Aggregates ◽  
The Cost ◽  
Concrete Matrix

Abstract Annually billions of tonnes of aggregates are extracted to apply in civil construction generating environmental impacts and energy consumption. So, based on circular economy principles applying residues as aggregates is a good solution to reduce the mining activity and to generate a more efficient destination for the residues. Thus, this research aims to evaluate the technical, economic, and environmental performance of concretes produced entirely with steel slag aggregates. The concretes were characterized through physical properties, as specific gravity, water absorption, compressive and tensile strength. Durability tests (expansibility) were also conducted. The authors analyzed the cost assessment and environmental impact of steel slag concrete production as well. The incorporation of steel slag increases the compressive and tensile strength of concrete, analyzed in different ages. Additionally, the steel slag does not present expansibility when confined in the concrete matrix. The entire replacement of natural aggregates for steel slag allowed to reduce in 31% the cement consumption, a decrease of 140 kg/m3, for the same strength class. The environmental analysis showed that the incorporation of steel slag aggregates reduced the cement intensity of concrete and its impact. Regarding the cost assessment, the mixtures with steel slag presented a lower cost compared to the conventional one. These results indicate that steel slag aggregates could be used in a cleaner production of concrete, replacing natural aggregates with no injury. This research provides the feasibility of using steel slag aggregates in a cleaner and cheaper concrete production and contribute to the promotion of sustainable solutions for the construction sector through the circular economy principles.

scholarly journals Viability of Using High Amounts of Steel Slag Aggregates to Improve the Circularity and Performance of Asphalt Mixtures

2022 ◽  
Vol 12 (1) ◽  
pp. 490
Author(s):  
Caroline Moura ◽  
Lucas Nascimento ◽  
Carlos Loureiro ◽  
Mafalda Rodrigues ◽  
Joel Oliveira ◽  
...  
Keyword(s):  
Circular Economy ◽  
Mechanical Performance ◽  
Permanent Deformation ◽  
Steel Slag ◽  
Cost Effective ◽  
Asphalt Mixtures ◽  
Raw Material ◽  
Water Sensitivity ◽  
Natural Aggregates ◽  
And Performance

Steel slag is a byproduct generated as waste during the steelmaking process and can be considered a cost-effective and environmentally acceptable alternative to replace natural aggregates. Using steel slag aggregates (SSA) to produce asphalt mixtures promotes sustainability and circular economy principles by using an industrial byproduct as a raw material. Thus, this work mainly aims to design more sustainable asphalt mixtures with high amounts of SSA that fit the circular economy expectations. This work developed two asphalt mixtures with SSA for surface (AC 14 surf) and binder/base (AC 20 bin/base) courses. Initially, the excellent wearing and polishing resistance of SSA and their good affinity with bitumen demonstrated the potential of this byproduct to be used in asphalt mixtures. Then, when analyzing the influence of using two different SSA incorporation rates (50% and a percentage close to 100%) in both asphalt mixtures, it was concluded that the use of SSA should be limited to 75% to avoid excessive air void contents and durability problems. The importance of considering the different particle densities of SSA and natural aggregates was highlighted during the mix design by defining a relationship between an effective and equivalent binder content. Finally, the mechanical performance of AC 14 and AC 20 with 75% SSA incorporation was compared to identical conventional mixtures produced with natural granite aggregates. The results obtained showed that the asphalt mixtures with 75% SSA have some workability problems due to the rough and porous surface of SSA. However, they present an excellent water sensitivity and permanent deformation resistance, surpassing the performance of the conventional asphalt mixtures.

scholarly journals Sustainability Potential Evaluation of Concrete with Steel Slag Aggregates by the LCA Method

2020 ◽  
Vol 12 (23) ◽  
pp. 9873
Author(s):  
Vojtěch Václavík ◽  
Marcela Ondová ◽  
Tomáš Dvorský ◽  
Adriana Eštoková ◽  
Martina Fabiánová ◽  
...  
Keyword(s):  
Life Cycle ◽  
Construction Industry ◽  
Raw Materials ◽  
Steel Slag ◽  
Physical And Mechanical Properties ◽  
Partial Replacement ◽  
Utilization Rate ◽  
Natural Aggregate ◽  
Concrete Production ◽  
Natural Aggregates

Sustainability in the construction industry refers to all resource-efficient and environmentally responsible processes throughout the life cycle of a structure. Green buildings may incorporate reused, recycled, or recovered materials in their construction. Concrete is as an important building material. Due to the implementation of by-products and waste from various industries into its structure, concrete represents a significant sustainable material. Steel slag has great potential for its reuse in concrete production. Despite its volume changes over time, steel slag can be applied in concrete as a cement replacement (normally) or as a substitute for natural aggregates (rarely). This paper focused on an investigation of concrete with steel slag as a substitute of natural gravel aggregate. Testing physical and mechanical properties of nontraditional concrete with steel slag as a substitute for natural aggregates of 4/8 mm and 8/16 mm fractions confirmed the possibility of using slag as a partial replacement of natural aggregate. Several samples of concrete with steel slag achieved even better mechanical parameters (e.g., compressive strength, frost resistance) than samples with natural aggregate. Moreover, a life cycle assessment (LCA) was performed within the system boundaries cradle-to-gate. The LCA results showed that replacements of natural aggregates significantly affected the utilization rate of nonrenewable raw materials and reduced the overall negative impacts of concrete on the environment up to 7%. The sustainability indicators (SUI), which considered the LCA data together with the technical parameters of concrete, were set to evaluate sustainability of the analyzed concretes. Based on the SUI results, replacing only one fraction of natural gravel aggregate in concrete was a more sustainable solution than replacing both fractions at once. These results confirmed the benefits of using waste to produce sustainable materials in construction industry.

scholarly journals REPLACEMENT OF NATURAL AGGREGATES USED IN ROAD STRUCTURES WITH STEEL SLAG

2021 ◽  
Vol XXVIII (2) ◽  
pp. 120-124
Author(s):  
Ion Chiricuta ◽  
Keyword(s):  
Natural Environment ◽  
Industrial Waste ◽  
Steel Slag ◽  
Road Construction ◽  
Base Layer ◽  
Flow Index ◽  
Natural Aggregates ◽  
The Cost ◽  
Marshall Stability ◽  
Modern Technologies

This work facilitates the application of modern technologies for road construction, by using steel slag instead of natural stone aggregates. This procedure will result in a significant decrease in the cost of works (slag, being an industrial waste, is much cheaper than natural aggregate). In the same time, the use of slag aggregates can result in protection of the environment, by eliminating slag storage spaces and by preserving the natural environment (extraction of natural aggregates may disturb groundwater and intensify erosion etc). Marshall stability, flow index and bulk density were determined for both kinds of aggregates, in order to find if the steel slag can safely replace the natural aggregates. By comparing the experimental results obtained for the two kinds of aggregates, it was confirmed the possibility of successfully using of steel slag as a substitute for natural aggregates in the base layer of a road structure.

scholarly journals Engineering Performance of Concrete Incorporated with Recycled High-Density Polyethylene (HDPE)—A Systematic Review

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1885
Author(s):  
Sonali Abeysinghe ◽  
Chamila Gunasekara ◽  
Chaminda Bandara ◽  
Kate Nguyen ◽  
Ranjith Dissanayake ◽  
...  
Keyword(s):  
Tensile Strength ◽  
High Density Polyethylene ◽  
Construction Material ◽  
High Density ◽  
Splitting Tensile Strength ◽  
Fiber Reinforced Concrete ◽  
Fine Aggregate ◽  
Aggregate Concrete ◽  
Sustainable Solutions ◽  
Concrete Matrix

Incorporating recycled plastic waste in concrete manufacturing is one of the most ecologically and economically sustainable solutions for the rapid trends of annual plastic disposal and natural resource depletion worldwide. This paper comprehensively reviews the literature on engineering performance of recycled high-density polyethylene (HDPE) incorporated in concrete in the forms of aggregates or fiber or cementitious material. Optimum 28-days’ compressive and flexural strength of HDPE fine aggregate concrete is observed at HDPE-10 and splitting tensile strength at HDPE-5 whereas for HDPE coarse aggregate concrete, within the range of 10% to 15% of HDPE incorporation and at HDPE-15, respectively. Similarly, 28-days’ flexural and splitting tensile strength of HDPE fiber reinforced concrete is increased to an optimum of 4.9 MPa at HDPE-3 and 4.4 MPa at HDPE-3.5, respectively, and higher than the standard/plain concrete matrix (HDPE-0) in all HDPE inclusion levels. Hydrophobicity, smooth surface texture and non-reactivity of HDPE has resulted in weaker bonds between concrete matrix and HDPE and thereby reducing both mechanical and durability performances of HDPE concrete with the increase of HDPE. Overall, this is the first ever review to present and analyze the current state of the mechanical and durability performance of recycled HDPE as a sustainable construction material, hence, advancing the research into better performance and successful applications of HDPE concrete.

Cost assessment of the bus fleet technical maintenance

2019 ◽  
Vol 39 (2) ◽  
pp. 90-95
Author(s):  
V. V. Turgeneva ◽  
V. D. Sekerin
Keyword(s):  
Cost Evaluation ◽  
Cost Assessment ◽  
Effective Management ◽  
Structure Investigation ◽  
Service Cost ◽  
Technical Maintenance ◽  
Maintenance Service ◽  
The Cost ◽  
Operating Company ◽  
Bus Transport

To assess the effectiveness of bus fleet technical maintenance, service cost evaluation should be organized. This cost analysis is essential for effective management at automobile operating company. The article describes the bus transport position in Moscow transport economy. The importance of technical maintenance in a bus transport system is defined. Special attention is given to the cost structure investigation.

scholarly journals Degradation Prediction Model for Friction of Road Pavements with Natural Aggregates and Steel Slags

2019 ◽  
Vol 10 (1) ◽  
pp. 32 ◽  
Author(s):  
Bruno Crisman ◽  
Giulio Ossich ◽  
Paolo Bevilacqua ◽  
Roberto Roberti
Keyword(s):  
Residual Life ◽  
Steel Slag ◽  
Steel Production ◽  
Threshold Level ◽  
Skid Resistance ◽  
Concrete Pavements ◽  
Cumulative Number ◽  
The Road ◽  
On The Road ◽  
Natural Aggregates

Steel production wastes (steel slags) are used more often in asphalt concrete pavements as a valuable replacement for natural aggregates, which are becoming increasingly rare. In this paper authors investigate the polishing characteristics of aggregates, and in particular of steel slags, used in bituminous road surfacing, are a major factor in determining the resistance to skidding. The main purpose of the study is the identification of a suitable degradation model, based on friction indicators, in the laboratory, as well as the comparison of in-situ pavement skid resistance with the cumulative number of passing vehicles over the years. The model predicts the expected resistance to skidding of the road surface based on the knowledge of the polished stone value (PSV) of the aggregates and the expected traffic on the road. In this study, several types of aggregates were compared: steel slag, limestone, limestone and slag mixture, diabase, Criggion stone and basalt. Using a standard PSV test, it was found that the aggregates did not reach the lower value of skid resistance (equilibrium value). The analysis of the British Portable Number (BPN) data versus polishing time allowed to empirically derive a regression model for each investigated aggregate. Hence, it appears possible to define both an investigatory level and threshold level to predict the actual residual life of the pavement from the examination of skid resistance.

scholarly journals Enhancement of Mechanical Properties and Porosity of Concrete Using Steel Slag Coarse Aggregate

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2865
Author(s):  
Md Jihad Miah ◽  
Md. Munir Hossain Patoary ◽  
Suvash Chandra Paul ◽  
Adewumi John Babafemi ◽  
Biranchi Panda
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Microstructural Analysis ◽  
Steel Slag ◽  
Physical And Mechanical Properties ◽  
Length Change ◽  
Sustainable Building ◽  
Burnt Clay ◽  
Lower Porosity ◽  
Furnace Steel

This paper investigates the possibility of utilizing steel slags produced in the steelmaking industry as an alternative to burnt clay brick aggregate (BA) in concrete. Within this context, physical, mechanical (i.e., compressive and splitting tensile strength), length change, and durability (porosity) tests were conducted on concrete made with nine different percentage replacements (0%, 10%, 20%, 30%, 40%, 50%, 60%, 80%, and 100% by volume of BA) of BA by induction of furnace steel slag aggregate (SSA). In addition, the chemical composition of aggregate through X-ray fluorescence (XRF) analysis and microstructural analysis through scanning electron microscopy (SEM) of aggregates and concrete were performed. The experimental results show that the physical and mechanical properties of concrete made with SSA were significantly higher than that of concrete made with BA. The compressive and tensile strength increased by 73% when SSA fully replaced BA. The expansion of concrete made with SSA was a bit higher than the concrete made with BA. Furthermore, a significant lower porosity was observed for concrete made with SSA than BA, which decreased by 40% for 100% SSA concrete than 100% BA concrete. The relation between compressive and tensile strength with the porosity of concrete mixes are in agreement with the relationships presented in the literature. This study demonstrates that SSA can be used as a full replacement of BA, which is economical, conserves the natural aggregate, and is sustainable building material since burning brick produces a lot of CO2.

scholarly journals Expandable Houses: An Explorative Life Cycle Cost Analysis

2021 ◽  
Vol 13 (12) ◽  
pp. 6974
Author(s):  
Charlotte Cambier ◽  
Waldo Galle ◽  
Niels De De Temmerman
Keyword(s):  
Life Cycle ◽  
Circular Economy ◽  
Life Cycle Cost ◽  
Lower Cost ◽  
Social Economic ◽  
Life Cycle Costs ◽  
Life Cycle Cost Analysis ◽  
Specific Design ◽  
Dynamic Perspective ◽  
Housing Needs

In addition to the environmental burden of its construction and demolition activities, the Flemish housing market faces a structural affordability challenge. As one possible answer, this research explores the potential of so-called expandable houses, being built increasingly often. Through specific design choices that enable the disassembly and future reuse of individual components and so align with the idea of a circular economy, expandable houses promise to provide ever-changing homes with a smaller impact on the environment and at a lower cost for clients. In this paper, an expandable house suitable for various housing needs is conceived through a scenario-based research-by-design approach and compared to a reference house for Flanders. Subsequently, for both houses the life cycle costs are calculated and compared. The results of this exploration support the proposition that designing expandable houses can be a catalyst for sustainable, circular housing development and that households could benefit from its social, economic and ecological qualities. It requires, however, a dynamic perspective on evaluating their life-cycle impact.

scholarly journals Comparison of Cement-Based and Polymer-Based Concrete Pipes for Analysis of Cost Assessment

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Orhan Bozkurt ◽  
Mehmet İslamoğlu
Keyword(s):  
Cost Effectiveness ◽  
Construction Industry ◽  
Cost Efficiency ◽  
Mechanical Efficiency ◽  
Polymer Concrete ◽  
Cost Assessment ◽  
New Techniques ◽  
Concrete Pipes ◽  
The Cost ◽  
Innovative Techniques

As the variety of materials utilized in construction industry has expanded, new techniques have been used in order to optimize the quality and efficiency of output. Therefore, recent innovations taking place in the construction industry led researchers to increase the mechanical efficiency of the output more than the cost effectiveness of it. However, especially professionals experiencing in the industry look into the cost effectiveness of the work. In other words, they also want researchers to justify the innovative techniques economically. The aim of this study is to provide a comparative analysis of the cost efficiency of polymer concrete used to manufacture durable and long-lasting reinforced concrete structures.

MODELING AND NUMERICAL SIMULATION OF AN ALGORITHM FOR THE INERTIAL SENSORS ERRORS REDUCTION AND FOR THE INCREASE OF THE STRAP-DOWN NAVIGATOR REDUNDANCY DEGREE IN A LOW COST ARCHITECTURE

2010 ◽  
Vol 34 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Lucian T. Grigorie ◽  
Ruxandra M. Botez
Keyword(s):  
Navigation System ◽  
Inertial Navigation System ◽  
Lower Cost ◽  
Inertial Sensors ◽  
Low Cost ◽  
Inertial Navigation ◽  
Noise Power ◽  
Integration Algorithm ◽  
The Cost ◽  
Miniaturized Sensors

In this paper, an algorithm for the inertial sensors errors reduction in a strap-down inertial navigation system, using several miniaturized inertial sensors for each axis of the vehicle frame, is conceived. The algorithm is based on the idea of the maximum ratio-combined telecommunications method. We consider that it would be much more advantageous to set a high number of miniaturized sensors on each input axis of the strap-down inertial system instead of a single one, more accurate but expensive and with larger dimensions. Moreover, a redundant system, which would isolate any of the sensors in case of its malfunctioning, is obtained. In order to test the algorithm, Simulink code is used for algorithm and for the acceleration inertial sensors modeling. The Simulink resulted sensors models include their real errors, based on the data sheets parameters, and were conceived based on the IEEE analytical standardized accelerometers model. An integration algorithm is obtained, in which the signal noise power delivered to the navigation processor, is reduced, proportionally with the number of the integrated sensors. At the same time, the bias of the resulted signal is reduced, and provides a high redundancy degree for the strap-down inertial navigation system at a lower cost than at the cost of more accurate and expensive sensors.

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