2031 research outputs found
Sort by
Estimation of Soil Loss using Remote Sensing Data in a Regional Tropical Humid Catchment Area
Get PDFSoil erosion has been and continue to be a major threat to environmental degradation especially in the developing countries. Accurate estimation of soil loss will provide reliable information in the management and mitigation solutions to soil erosion. In this study, the soil loss in an erosion prone Anambra State of South East region of Nigeria was estimated. Due to the complex nature of the catchment characteristics of Anambra State, soil loss cannot be estimated precisely by mere application of conventional soil erosion model. Hence a site-specific methodology was developed and applied. Revised Universal Soil Loss Equation (RUSLE) was integrated with the Geographic Information System (GIS) of the environment using remote sensing to build the model. 40-years rainfall data was collated from the Nigeria Meteorological Agency and analyzed. The various parameter of RUSLE which includes: Rainfall Erosivity (R), Soil Erodibility (K), Topography (LS), Land Use and Land Cover (C), and Erosion Control practices (P) were developed and imposed into ArcGIS 10.6 to estimate the amount of annual soil loss in the area. The result indicated that about 27.58km2 (0.59%) of the study area have very low erosion rate of 0 – 5 t ha1year-1 , while the rates of erosion in 1311.52km2 (28.01%), 538.59km2 (11.50%), 1649.08km2 (35.22%), 959.09km2 (20.48%), and 196.76km2 (4.20%) of the study area are 5–10, 10–15, 15–25, 25–50 and >50 t ha-1year-1respectively. This knowledge will help decision makers in managing the land degradation problems in Anambra State of Nigeria. Doi: 10.28991/CEJ-2024-010-07-014 Full Text: PD
Retrofitting Bolted Flange Plate (BFP) Connections Using Haunches and Extended End-Plates
Get PDFIn Indonesia, one of the most common forms of connection is the Bolted Flange Plate (BFP) moment connection. Nevertheless, their current setups do not satisfy the strict requirements outlined in AISC 358-22. Therefore, this study uses advanced sub-assemblage numerical modeling simulations using ANSYS software to propose a novel way to integrate a half WF extended end-plate connection and trapezoidal haunch in order to fortify BFP moment connections, which does not meet the requirement required by AISC 358-22. Methodologically, the research entails comprehensive modeling and analysis of the proposed retrofit scheme. Six distinct connection models were scrutinized: the BFP-UR representing the existing connection extracted from a structure in Surabaya; the BFP-R4E and BFP-R4ES models, embodying connection retrofits with a half WF extended end-plate; and the BFP-RTR and BFP-RSTR models, embodying connection retrofits with a trapezoidal haunch. Additionally, the BFP-RTRE model integrates both an extended end plate and a trapezoidal haunch in the retrofit scheme. The analytical findings unveil that the proposed strengthening paradigm manifests heightened and superior rotational moment characteristics relative to the pre-reinforcement configuration, albeit encountering stiffness degradation attributable to buckling effects on the main beam. Notably, the analysis indicates that degradation ensues when rotational displacement exceeds 4%, with only the BFP-RTR and BFP-RSTR models exhibiting degradation at a 3% rotation threshold. Crucially, the connections demonstrate the capability to withstand 80% of the beam's plastic moment under a 4% rotational displacement, thereby aligning with the stringent requisites delineated in AISC 341-22. Doi: 10.28991/CEJ-2024-010-08-03 Full Text: PD
Research into Uranium Characteristics and Content in a Pregnant Solution During Leaching with Oxygen Saturation
Get PDFThe aim of this study is to intensify the process of in situ leaching of uranium with saturation of the working solution with oxygen using a Venturi tube. One of the ways to increase the efficiency of underground leaching is to saturate the leaching solution with oxygen. However, this oxidizer has not found application due to the complexity and high cost of oxygen saturation in the solution. The results of the study showed that saturation of the leaching solution with oxygen using a Venturi tube leads to a decrease in the concentration of divalent iron and an increase in the concentration of trivalent iron. Thus, this leads to an increase in the average uranium content in the pregnant solution by 21.3% compared with the technology being used. The dependence of changes in the concentration of trivalent iron and the uranium content in the pregnant solution on the leaching time was obtained when the solution was saturated with oxygen. The application of the proposed technology of oxygen saturation in the solution will increase the uranium content in the pregnant solution and thereby shorten the time required to mine uranium reserves in the technological block. Doi: 10.28991/CEJ-2024-010-05-016 Full Text: PD
Use of Recycled Ceramic Powder as a Green Alternative in Mortar-Based Cementitious Composites
Get PDFRecognizing material waste as a significant global concern has influenced both the environment and the construction industry. The utilization of ceramic waste as a recycled material in construction projects has gained attention as an effective and sustainable approach to address environmental issues. This study examines the use of waste ceramic tile powder (WCTP) as a supplementary material in cement mortars to decrease the amount of cement required. WCTP was used in place of cement at percentages of 5%, 10%, and 20%. Four different mix designs were created and tested for the study, yielding a total of 48 specimens. Numerous investigations were carried out, including flow table evaluations, measures of dry density, assessments of compressive and flexural strengths, X-ray diffraction, and SEM-EDX testing. The objective of these investigations was to evaluate the specimens' mechanical and physical characteristics as a whole. The findings showed that using ceramic powder in place of some cement might enhance the properties of the mortar. The compressive and flexural strengths of the mortar were notably impacted by replacing 10% of the cement content with ceramic powder. The inclusion of ceramic powder significantly enhanced the mortar's microstructure interface, according to SEM-EDX studies. In the end, the utilization of ceramic powder was found to have a substantial positive impact on the environment by reducing waste. Doi: 10.28991/CEJ-2024-010-10-03 Full Text: PD
Shear Performance of Deep Concrete Beams with Openings Using Waste Tyre Steel Fibres: FEM and ANN Analysis
Get PDFThe creation of transverse openings in beams triggers the shear performance. The dual impact of height and length on the overall shear performance and strain variations in reinforcements of deep concrete beams with and without fibres was assessed to investigate the effect of opening in the beam. This effect of opening was explored and modelled using finite element software Abaqus and predicted using an artificial neural network (ANN) model. The data set for ANN was 56 deep concrete beams, while for the finite element model (FEM), 12 deep concrete beams were used. The effect of input parameters in the ANN model was assessed through sensitivity analysis. Results show that with an increase in opening depth, the strain in top steel reinforcement shifted to tensile strain, resulting in premature beam failure. In addition, experimental and FEM shear resistance had a mean absolute error (MAE) of 4.1, 5.0, and 20.6% for deep beams without fibres, with fibres and fibre mesh, respectively. Compared to available analytical models, the ANN model reasonably predicts the shear resistance with an R2of 0.84 and a mean square error (MSE) of 0.01. The use of the ANN and FEM models is recommended as they save time, and the prediction does not involve degradation of the environment, hence demonstrating sustainable construction practices. Doi: 10.28991/CEJ-2024-010-08-02 Full Text: PD
Frictional Axial Resistance of Clamped Split Pocket Mechanism Steel Structural Joint: An Experimental Study
Get PDFThe Clamped Split Pocket Mechanism (CSPM) prefabricated joint system was developed for a single-story steel instant house, designed to be compact and rapidly constructed without modifying the end of the beam and column element member. The CSPM bolted joint system was proposed as an optimal solution for post-disaster housing, especially after earthquakes. Despite its potential, the frictional tensile resistance behavior of the CSPM bolted joint system has not been previously studied, necessitating experimental investigation. This study examined the frictional tensile resistance behavior of the CSPM joint system by monitoring the effective friction coefficient under axial tension force. The experiments considered both the strong and weak axes of the joint and utilized two configuration types of specimens (L and T) with varying bolt pretensions of 2.5, 5, 7.5, and 10 kN. Results indicated that the effective friction coefficient of the CSPM bolted joint system ranged from 0.19 to 0.26, correlated to bolt pretension. Increased bolt pretension resulted in larger surface deformation of the split pocket, triggering a not uniform frictional tensile resistance across the steel surfaces of the split pocket joint. From this study, the achieved effective friction coefficients could guide the design of minimum pretension forces for clamps in prefabricated steel instant houses. Doi: 10.28991/CEJ-2024-010-09-07 Full Text: PD
Risk-Based Method-Technology Integration on Spun Pile Production for Product and Service Quality
Get PDFThe research aims to identify the risk factors and the medium-high risks to use as the basis for the innovative method of spun pile manufacturing technology. The research uses the Delphi method to analyze and review the validity of content construction, pilot and respondent surveys, focus group discussions, and expert validation. The findings show utilizing and optimizing the technology on production machinery is influential for results on both product and service quality. The dominance category in the medium-risk technology indicates the need for improvement in the operator's competence. The result also indicates the largest medium risk is during the initial integration, Cutting and Heading at 84%, and the final step, Stressing and Spinning, at 59%. The research improvement to map the production process is related to the medium and high risks to know where and how the industry can improve. This risk-based technology and integration method is a proposed method using an approach to innovation management by reducing the risk values. Innovation by improving the standard operational procedure (SOP) was based on the relation of each activity during the integration within the risk category of medium-medium, medium-high, and high-high. We recommend improving SOP and utilizing information technology on precision for both subprocesses. Doi: 10.28991/CEJ-2024-010-11-015 Full Text: PD
BIM Adoption in MENA's Construction Industry: A Contractor's Perspective
Get PDFThis study delves into the multifaceted landscape of Building Information Modeling (BIM) adoption and implementation across the Middle East and North Africa (MENA) region's construction industry. Employing an online survey methodology, the research scrutinizes the varied profiles of contractors. Through regression analysis, the study investigates the impact of institutional pressures on the contractors' BIM adoption, implementation, encountered barriers and challenges, expected benefits and outcomes, and related expertise and training. The analysis then extends to evaluate the interrelationships among such BIM variables. The key findings reveal significant influences of institutional pressures on BIM adoption and benefits as well as their expected benefits and outcomes but less impact on overcoming BIM barriers and challenges and enhancing expertise and training. The research highlights the limited role of BIM expertise and training in the adoption, implementation, and realization of its benefits and outcomes within the MENA construction sector. Furthermore, the study concludes that barriers, challenges, benefits, and outcomes don't have a significant effect on BIM's adoption and implementation. The study also evaluates the primary benefits and outcomes of BIM alongside the main barriers and challenges encountered. Crucially, the research identifies and dissects the salient barriers to BIM deployment, such as awareness and expertise deficiency, financial and human resource constraints, training shortages, and resistance to change. This study not only provides a detailed snapshot of the BIM landscape but also lays the groundwork for addressing the persistent challenges and harnessing the full potential of BIM in revolutionizing construction methodologies in the MENA region. Doi: 10.28991/CEJ-2024-010-08-015 Full Text: PD
Polyethylene Terephthalate Modified Asphalt Concrete with Blended Recycled Aggregates: Analysis and Assessment
Get PDFThe research study attempts to ascertain the mechanical performance of asphalt concrete, using reclaimed asphalt concrete pavement (RAP) and recycled concrete aggregate (RCA) blends with polyethylene terephthalate (PET) as a modifier. The influence factors were evaluated, including RAP/RCA ratios and PET contents on static and cyclic performances. The static performance was assessed through the indirect tensile strength (ITS) tests, while the cyclic performance was assessed through the indirect tensile resilient modulus (ITMR), indirect tensile fatigue life (ITFL), and wheel tracking tests. Compared to asphalt concrete using natural aggregate (NA), the ITMR of RAP-RCA-PET asphalt concretes was higher when PET contents were between 0.2% and 0.6% for RAP/RCA = 80/20. The ITFL of RAP-RCA-PET asphalt concretes was found to be higher than that of NA asphalt concrete when PET contents ranged from 0.2% to 0.6% for RAP/RCA < 90/10. The ITFL was also higher when PET content was between 0.4% and 0.6% for RAP/RCA = 100/0. RAP-RCA-PET asphalt concretes exhibited lower rut depth than NA asphalt concrete with RAP/RCA = 90/10 and 60/40 at PET contents of 0.4% to 1.0% and with RAP/RCA = 80/20 at PET contents of 0.2% to 1.0%. The RAP/RCA = 80/20 and PET content = 0.6% were found to be the best ingredient in term of both fatigue cracking and rutting resistances. As per the systematic analysis, the fatigue distress models of RAP-RCA-PET asphalt concretes for various PET contents were developed in term of ITFL and tensile strain (𔜀𔑡) relationship and useful for mechanistic design. The results of this research will contribute to promoting RAP-RCA-PET asphalt concrete as a greener material in pavement construction. Doi: 10.28991/CEJ-2024-010-11-08 Full Text: PD
Effect of Climate Change on Wetland Areas in West Iraq Using Satellite Data and GIS Techniques
Get PDFIraq is considered to amongst those countries in the Middle Eastern region that are most exposed to the effects of climate change, which will have notable effects on wet areas and lakes. Natural or industrial water resources must be paid particular attention due to their importance in preserving environmental and biological systems, in addition to their economic and social importance. As a result of the effects of climatic change, water resources in Iraq have seen a multitude of changes. The aim of this study is to determine changes in the wetland area around AL-Razzaza Lake, Karbala province, Iraq, during the years 2000, 2005, 2010, 2015, and 2023. Landsat 5 satellite data from 2000, 2005, and 2010, and Landsat 8 and 9 data for 2015 and 2023, respectively, were used in this analysis, which was conducted using NDWI as a free, open-source program (ArcMap 10.8) to detect these changes; NDWI is a natural water anisotropy index used to detect the surface area of bodies of water in satellite images. The results revealed a clear decrease throughout the study period, as the wetland area of the lake in 2000 was 1189.7 km2, which represents a decrease of 34.3% compared to the total area of the lake (1810 km2); it decreased by 52.7% in 2005 (855.5 km2) and continued to decrease for 2010, 2015, and 2023, by 79.2%, 80%, and 85%, (376.5 km2, 362.9 km2, and 270.4 km2, respectively). The wetland area of Al-Razzaza Lake decreased between 2000 and 2023 by 919.3 km2, that is, an average of 40 km2per year. It was found that the lake wetland area sharply declined over the study period due to a lack of water surface resources via the Euphrates River, as well as climatic changes and poor water resource management. It is anticipated that the lake will lose more than half its current wetland area by 2040 if the current decline continues. These results are considered important in terms of preparing a strategic plan to preserve water bodies and wet areas in Iraq, including Al-Razzaza Lake. Remote sensing and GIS technologies have played a major and essential role in detecting such changes. Doi: 10.28991/CEJ-2024-010-09-013 Full Text: PD