2031 research outputs found
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Properties and Microstructure of Treated Coal Bottom Ash as Cement Concrete Replacement
Get PDFSustainable construction is a rapidly growing area of research focused on using industrial waste to replace Portland cement in concrete. This approach not only reduces CO2emissions from cement production but also serves as an effective way to diminish the environmental impact of concrete production. This study aims to investigate the properties of Coal Bottom Ash (CBA) after undergoing two different treatments: flotation and burning. It also evaluates the impact of CBA as a cement replacement in concrete with different replacement percentages (5%, 10%, 15%, and 20%). Chemical analysis of CBA has revealed that it can be classified as a pozzolanic material due to its high content of silicates, aluminates, and iron oxides. The microstructure of CBA showed a porous, angular, and irregular surface with many voids. The findings of this study revealed that the optimum mix was 10% CBA, resulting in a 2% increase in compressive strength compared to the control mix after 56 days of curing. Additionally, the study evaluated the effects of sulfate and chloride on concrete. It was found that the mix with the burning treatment showed an overall increase in strength, while the flotation treatment did not reach the control mix's strength in any of the curing periods. Furthermore, the results demonstrated that CBA has significant potential as a cement replacement material, and the burning treatment showed improvement in concrete's overall properties compared to the raw material in terms of mechanical and chemical properties while reducing greenhouse gas emissions and enhancing the environment. Doi: 10.28991/CEJ-2024-010-04-08 Full Text: PD
Optimizing Alkali-Concentration on Fresh and Durability Properties of Defected Sanitary Ware Porcelain based Geopolymer Concrete
Get PDFIntroducing defective sanitaryware porcelain as a low-calcium binder for geopolymer mix concrete was regarded as green concrete. Four alkali concentrations (8M, 10M, 12M, and 14M) mixes involving four initial curing temperatures (60°C, 75°C, 90°C, and 105°C) were investigated for porosity, rapid chloride penetration, compressive and abrasive resistance. Tests on geopolymer paste for consistency and initial and final setting times were also assessed. For all the mixes, consistency and setting time decreased with increased alkali concentration levels. An increment in curing temperature increased the setting time rate. Microstructural studies such as X-ray fluorescence analysis (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were carried out, and the results were presented. The compressive and abrasive resistance of the specimen performance increased with an increase in the initial curing temperature and alkali concentration level. Majorly, the mechanical strength of porcelain-based geopolymer specimens increased by increasing the alkali concentration level. Applying 105°C for the initial curing temperature to the specimen, compressive strength, abrasive resistance, and resistibility to chloride ingress of the specimen enhanced. At the 28-days curing period, the ultimate compressive strength was 68.03 N/mm2, the lowest weight loss from abrasive motion was 0.09%, and the lowest passing charge was 1,440.91 coulombs were recorded respectively. As a result, porcelain-based geopolymers required a high initial curing temperature and a high alkali concentration level. It was found that 14M porcelain-based specimens heated at 105°C curing temperature for 24 hours led to an eco-friendly concrete mix with prominent positive results for engineering properties. Doi: 10.28991/CEJ-2024-010-04-05 Full Text: PD
Assessing Air Quality Using Multivariate Statistical Approaches
Get PDFThe purpose of the current study was to evaluate air quality in Dong Thap province, Vietnam. The air quality data was collected during 2019–2020, representing the time of pre- and mid-COVID-19. Twenty-seven air quality samples (in the areas of urban, residential-administrative, hospital-schools, and industry-craft village areas) were used for the evaluation. Air quality was evaluated using national technical regulations on air quality, including QCVN 26:2010/BTNMT and QCVN 05:2013/BTNMT. The difference of mean air quality between the areas was examined using a one-way ANOVA followed by the Duncan test at a significant level of 5%. The relationship between air quality parameters and microclimate factors was tested using Pearson correlation. Principal component analysis (PCA) was utilized to identify critical variables and potential sources of air variation. Cluster analysis (CA) was applied to group similar air quality sites, thus recommending air monitoring site selection. The results show that the air quality in the study area is not polluted. The concentrations of noise, TSP, SO2, and NO2in the mid-COVID-19 pandemic were significantly lower than those in the pre-COVID-19 pandemic due to the social distancing policy. There was a close correlation among air quality parameters, except for air humidity. PCA identified two to four potential sources of air variation, explaining 84.3%, 100%, 100% and 89.7% of the total air quality variance at urban, residential–administrative, hospital-schools, and industry-craft villages, respectively. CA divided the 27 sampling sites into eight groups by the differences, mainly in humidity, wind speed noise, TSP, and CO. Eight sampling sites could be potentially reduced from the current monitoring program for representativeness and cost-effectiveness purposes. All air parameters in the current study are significant for monitoring, and the potential sources of air quality variation are traffic activities, industrial production, craft village activities, and daily life using fuels in residential areas. The results of the current study provide useful information for air quality monitoring and management. Future monitoring programs should include toxic air pollutants in air quality monitoring programs. Doi: 10.28991/CEJ-2024-010-02-012 Full Text: PD
Mechanical and Microstructural Properties of Geopolymer Concrete Containing Fly Ash and Sugarcane Bagasse Ash
Get PDFPortland cement plays a vital role in construction and building projects. However, its manufacturing process releases detrimental pollutants and contributes to climate change. The environmental concerns linked to the manufacturing of conventional Portland cement, such as its high energy demands, raw material consumption, and significant CO2 emissions, have prompted the need to look for alternatives such as geopolymer or green concrete. In addition, indiscriminate disposal of waste might have a detrimental effect on the environment. This paper investigates the mechanical and microstructural properties of geopolymer concrete incorporating fly ash and sugarcane bagasse ash as primary constituents. Sugarcane bagasse ash (SCBA) was employed as a partial substitute for Fly Ash (FA), with varying proportions ranging from 5% to 20% with increments of 5%. Alkaline activators utilized were NaOH (14M) and Na2SiO3, with a ratio of 1.5. Various tests, including the slump test, compressive strength test, splitting tensile strength test, and flexural strength test, were performed. The microstructural characteristics were assessed by scanning electron microscopy (SEM), energy dispersive analysis (EDS), and X-ray diffraction analysis (XRD). The results revealed that adding sugarcane bagasse ash influenced the workability of geopolymer concrete while enhancing its mechanical properties. The research findings have shown that the mixture comprising 5% SCBA has the greatest compressive strength of 64 MPa. Doi: 10.28991/CEJ-2024-010-04-018 Full Text: PD
Utilizing Remote Sensing and GIS Techniques for Flood Hazard Mapping and Risk Assessment
Get PDFIn this paper, a comprehensive flood hazard map for the vicinity of King Talal Dam in Jordan, utilizing advanced remote sensing (RS) and GIS methodologies, is developed. Key geographical and environmental factors, encompassing terrain slope, elevation, aspect, proximity to water streams, drainage density, and land use/land cover, are integrated to highlight areas with increased flood risk. This study, by employing a novel theoretical approach, harnesses the synergistic capabilities of RS and GIS to collect and analyze geospatial data. The Analytic Hierarchy Process (AHP) is applied to assign weights to various flood-conditioning factors, quantifying their relative importance in flood risk assessment. Through the weighted sum overlay technique, the aforementioned factors are integrated to categorize flood risk levels from very low to very high. This study successfully maps flood hazards, identifying areas near main water channels, ravines, and lower-elevation areas prone to flooding. This research provides a robust framework for flood risk assessment, contributing valuable knowledge to the fields of environmental management and disaster mitigation. It underscores the importance of continuous monitoring and updating of flood hazard maps to accommodate changing land use, climate, and hydrological conditions. The innovative application offers crucial insights for urban planners and policymakers, emphasizing the need for proactive strategies in flood-prone areas and serving as a model for similar geographical regions. Doi: 10.28991/CEJ-2024-010-05-05 Full Text: PD
A Review of Biomineralization as Solution for Roads and Infrastructures Concrete Sustainability
Get PDFConcrete cracks in roads and infrastructure are ubiquitous due to environmental factors, fatigue, and material degradation. Applying bacteria with self-healing capabilities in concrete matrices is proposed as a solution. These bacteria, activated by water and oxygen ingress, produce calcium carbonate through biomineralization. They are improving structural integrity while reducing the adverse effects of chemical and water infiltration. The quantity of Bacillus bacteria to be added to the concrete mixture is an integral part of the standardization of the self-healing mechanism. 105 - 108 cells/mL of spores experienced improvement in mechanical properties and self-healing efficiency. Various Bacillus strains, such as Bacillus sphaericus, Bacillus subtilis, and Bacillus megaterium, are typically utilized in self-healing. The by-product of biomineralization, calcium carbonate, is an autonomous crack and pore sealer, which can be evaluated via SEM, XRD, and XDS. The study highlights the testing methodologies used to examine calcite deposition. Also, it reiterates the importance of urease activity evaluation before bacterial propagation to confirm the occurrence of the biomineralization process. Moreover, the article reiterates the bacteria's history, origin, and pathogenicity, bridging the gap concerning bacteria propagation safety and the need for industry-accepted standards and certification procedures. The transition from laboratory experiments to large-scale implementation is advocated to demonstrate bacterial concrete's sustainability and economic feasibility for broader industry adoption. Finally, bacteria concrete is a ground-breaking approach that unites construction and biology for long-term sustainable transportation materials and construction. Doi: 10.28991/CEJ-2024-010-08-020 Full Text: PD
Application of Soft Computing to Address Uncertainty in Construction Project Management: A Systematic Literature Review
Get PDFDecision-making in Construction Project Management (CPM) involves numerous ambiguous information and uncertainties due to the nature of construction project. The Soft Computing (SC) approach, which offers several data processing strategies under uncertainty, has been extensively researched in CPM studies for decision problem solving. Decisions that cannot be adequately handled by conventional computer systems are facilitated by the SC approach. The SC approach encompasses a variety of SC techniques that are constantly developing and becoming more widely used to address real construction challenges. This study aims to conduct Systematic Literature Reviews (SLR) on the development of mainstream SC techniques and their current application in construction projects. Using an inventive SLR technique, 83 CPM papers covering the years 2018 to 2023 were selected for this study and then classified into four primary application themes of SC in CPM. The research trend was then described using bibliometric analysis. Afterwards, a topic-based qualitative analysis was conducted to investigate the application of SC approaches in the construction field. Several potential challenges to current research were then elaborated. It also contributed to suggesting future directions for the advancement of SC techniques that would be advantageous for construction research and practice. Doi: 10.28991/CEJ-2024-010-06-020 Full Text: PD
The Influence of Customer Relationships on Supply Chain Risk Mitigation in International Logistics
Get PDFAdequate transportation and administration of products and resources across borders are crucial in the logistics industry, particularly in locations such as the China-Pakistan Economic Corridor (CPEC). However, other hazards are associated with this, including global disputes, geopolitical tensions, trade battles, natural catastrophes, terrorist threats, and security breaches, all of which can disrupt the supply chain. These hazards highlight the need for robust supply chain risk management (SCRM) strategies to ensure the seamless distribution of products and services in the face of adversity. To address these challenges, this study examines the impact of customer relationships (CR) on supply chain risk management in the CPEC logistics sector. A survey conducted across various transportation and logistics firms' sites obtained data from 500 staff members. After removing 50 partial replies, 450 total responses were considered. The information also includes reactions for operational supply chain risk management (OSCRM), organization performance (OP), strategic supply chain risk management (SSCRM), and customer relationship (CR). To evaluate the respondents of the survey questionnaire using the Likert scale. Partial least squares structural equation modeling (PLS-SEM) is utilized to validate the hypothesis, which is used for statistical analysis, validation of structural models, and measurement models. The measurement model established the measure's validity and reliability, while other approaches demonstrated discriminant validity. The structural model is employed to identify the significant relationships between CR and SCRM in the logistics sector. The findings emphasize CR's importance in managing the supply chain's inherent constraints, contributing to CPEC's sustainability. Overall, this research attempts to enhance understanding of the complex relationship between CR and SCRM in the dynamic world of global logistics. Doi: 10.28991/CEJ-2024-010-06-010 Full Text: PD
Experimental Study on Seismic Performance of Kancingan Timber Frame Infill Walls Building
Get PDFThis study was carried out to examine the seismic performance of Kancingan house walls and the behavior of their timber frames, brick infill, and anchor nails during cyclic loading tests. Kancingan House, a timber frame building with brick infill walls, is a cost-effective and efficient method of wall construction commonly used in houses in Merauke, Indonesia. The experimental method was used to determine the seismic performance of the walls built using buswood with a module width of 100 cm and a height of 130 cm through cyclic load testing. The result showed a maximum lateral load of 26.43 kN with a displacement of 19.08 mm under compression loading and 28.78 kN under tensile loading with 15.6 mm displacement. The initial stiffness was measured at 5.03 kN and 9.59 kN/mm for compressive and tensile loading, respectively. Furthermore, ultimate load and displacement of 21.14 kN and 23.02 kN were obtained at a displacement of 30.68 mm under compressive loading and 25.23 mm under tensile loading. The ductility values of 10.76 and 9.78 were obtained under compressive and tensile loading. In conclusion, the study found that each wall element supports the seismic performance of the structure. As opposed to the timber frame, the infill walls have not suffered much damage except a hair crack because of the presence of anchor nails that keep the infill wall from collapsing when it loses its bond with the timber frames. Doi: 10.28991/CEJ-2024-010-08-06 Full Text: PD
Managing Green and Sustainable Technologies: Climate-Informed Corrosion Prediction for Steel Structures
Get PDFThe unpredictability of atmospheric circumstances is one of the major elements that contribute to the capability to anticipate the corrosion growth in metal structures over time accurately. Climate shifts can potentially modify the long-term attributes of these factors throughout the operational life of metal structures, both those currently in existence and those newly developed. The impact of climate irregularity on the probabilistic nature of atmospheric variables, which significantly impact corrosion situations, can add intricacy to corrosion predictions in these constructions. This project presents an incorporated framework to quantify the impact of climate alteration on the corrosion rates of steel structures in Jordan. It considers the changes in environmental conditions, specifically temperature, relative humidity, and wind speed, and their impacts on atmospheric corrosion. Global Climate Models are employed to assess the long-term effects of climate transformation on these environmental circumstances. An analytical model for anticipating corrosion rate is integrated with climate transformation models to predict modifications in the corrosion rates of steel parts relative to historical situations. This project also examines the impact of climate transformation on the fluctuations of these climatic parameters and offers a contrast between historical data and projected conditions across the country. The findings indicate a significant increase in corrosion rates across Jordan, which calls for localized green building codes and standards to ensure that future infrastructure is sustainable and capable of withstanding the new climatic norms. This approach addresses the immediate challenges posed by climate change and contributes to the broader goals of sustainable urban development and managing green technology adoption in Jordan. Doi: 10.28991/CEJ-2024-010-08-016 Full Text: PD