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Investigating Barriers to the Adoption of Energy Management Practices for Sustainable Construction Projects: SEM and ANN Approaches
No full textThis research addresses the critical challenges hindering the integration of Energy Management Practices (EMPs) within the construction industry, impeding its progress toward sustainability. Recognizing the pivotal role of EMPs in fostering sustainable practices, this study aims to fill a notable research gap by conducting a meticulous survey involving 100 industry professionals. Through the application of Partial Least Squares Structural Equation Modeling (PLS-SEM) and Artificial Neural Network (ANN) analyses, this study provides a comprehensive exploration of the intricate barriers and their interrelated dynamics within the construction sector. The findings reveal significant financial obstacles, including higher initial costs and limited financing options, underscoring the need for interventions to alleviate financial constraints. Additionally, policy and regulatory challenges, such as limited government incentives and shifting energy management rules, are identified, highlighting the necessity for stable and supportive regulatory environments to foster EMP adoptions. This research provides unique insights into the barriers hindering EMP adoption within the construction sector. The implications of this study extend beyond EMP adoption, offering a foundation for advancing sustainable practices in the construction industry. The insights gained can inform both academic research and practical decision-making, contributing to the ongoing discourse on sustainability in construction. Doi: 10.28991/CEJ-2024-010-04-015 Full Text: PD
Ultimate Strength of Internal Ring-Reinforced KT Joints Under Brace Axial Compression
No full textInternal ring stiffeners are frequently used to improve the ultimate strength of tubular joints in offshore structures. However, there is a noticeable absence of specific design guidance regarding the assessment of their ultimate strengths in prominent offshore codes and design guides. No equations are available to determine the ultimate strength of internal ring-reinforced KT joints. This work developed equations to determine the ultimate strength and the strength ratio of internal ring-reinforced KT joints based on numerical models and parametric studies comprising ring parameters and joint parameters. Specifically, a finite element model and a response surface approach with eight parameters (λ, δ, ψ, ζ, θ, Ï„, γ, and β) as inputs and two outputs (ultimate strength and the strength ratio) were evaluated since efficient response surface methodology has been proven to give precise and comprehensive predictions. KT-joint with parameters λ=0.9111, δ=0.2, ψ=0.7030, ζ=0.3, θ=45°, Ï„=0.90, γ=16.25, and β=0.6 has the maximum ultimate strength, and the KT-joint with parameters: λ=1, δ=0.2, ψ=0.8, ζ=0.5697, θ=45°, Ï„=0.61, γ=24, and β=0.41 has the maximum strength ratio. The KT-joints with the optimized parameters were validated through finite element analysis. The percentage difference was less than 1.7%, indicating the applicability and high accuracy of the response surface methodology. Doi: 10.28991/CEJ-2024-010-05-012 Full Text: PD
A Review of Biomineralization as Solution for Roads and Infrastructures Concrete Sustainability
No full textConcrete 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
Assessing Multifaceted Effects of Speed Humps and Bumps: Travel Time, Safety, and Environmental Considerations
No full textThis study focuses on investigating the significant impacts of speed breakers on various parameters, including travel time delays, vehicle speeds, fuel consumption, pavement maintenance costs, and vehicular exhaust emissions. Field data was collected and analyzed to assess the effects of different types of traffic calming measures on these parameters. The findings provide valuable insights into the implications of speed breakers on road safety, environmental pollution, and overall road infrastructure management. The results reveal that the implementation of speed humps, speed bumps, and triple bumps effectively slows down vehicles, as evidenced by considerable reductions in the 85th percentile speeds. The reduction percentages were 41.65% for speed humps, 73.52% for speed bumps, and 86.27% for triple bumps. This indicates the effectiveness of these traffic calming measures in improving road safety by reducing vehicle speeds. However, the presence of speed breakers also leads to increased travel time delays. On average, traversing stretches with speed humps, speed bumps, and triple bumps resulted in delays of 9.31, 16.42, and 29.51 seconds, respectively. While the individual delay times may appear relatively short, the cumulative effect of multiple speed obstacles along a road needs to be considered. Another significant impact observed is the increased fuel consumption associated with speed breakers. The study found that for every 100 km of travel, motorcycles and passenger cars consumed approximately 12.07 km and 27.37 km of additional fuel, respectively, when the density of speed breakers was 1.33/km. This translates to a fuel consumption increase of 13.73% for motorcycles and 37.74% for passenger cars. Furthermore, the presence of speed humps was found to contribute to pavement deterioration, as indicated by decreased Pavement Condition Index (PCI) values. The study also revealed that sections with speed humps incurred significantly higher maintenance costs compared to sections without speed humps. The increase in maintenance cost ranged from 100 to 264% across different road sections, with higher traffic volumes leading to greater cost escalation. Additionally, the study confirms that lower vehicle speeds, particularly between 0-15 km/hr, are associated with higher emissions of pollutants, including carbon monoxide (CO) and other pollutants. This highlights the environmental implications of speed breakers and their contribution to urban air pollution. Doi: 10.28991/CEJ-2024-010-07-07 Full Text: PD
Performance Index Model of Small Dam in Semi-Arid Area
No full textThe aim of this research is to build a model of small dam performance index in semi-arid areas by considering 4 aspects that are physical, institution, service, and operation and maintenance aspects. Research locations are 85 small dams that spread to 8 islands and 5 SWS in 22 regencies in Nusa Tenggara Timur Province. The data consists of secondary data from BWS NT II and primary data from survey results and survey blank filling to 85 locations of small dams in the field. The methodology consists of Structural Equation Modeling Partial Least Squares (SEM-PLS) and Generalized Reduced Gradient (GRG). The analysis result shows that physical; institution; service; and operation and maintenance aspects are significantly influenced by the performance index of small dams. The structural analysis expresses that physical; institution; service; and operation and maintenance aspects are positively and significantly influenced by the performance index of small dams. The novelty in this research is the performance index of small dams that is successfully developed and tested by using field data and GRG. In addition, this model gives accurate value to the performance index of small dams in semi-arid areas in Nusa Tenggara Timur Province. However, the performance index model of small dams in semi-arid areas is formulated as follows: IK physical = 0.093 KT + 0.128 KTE + 0.159 KBS + 0.087 BPL + 0.155 JD + 0.145 KBLY + 0.233 KBP; IK institution = 0.58 DOP + 0.42 RA; IK service = 0.56 KBL + 0.09 AM + 0.12 VG + 0.09 WK + 0.14 PA; IKOM = 0.360 PKOP + 0.515 PPE + 0.125 KSOP. The general formulation for performance index of small dams is I IDK-Pentewati = 0.15 IK physical + 0.12 IK institution + 0.20 IK service + 0.53 IK OM. Doi: 10.28991/CEJ-2024-010-08-014 Full Text: PD
Artificial Intelligence Using FFNN Models for Computing Soil Complex Permittivity and Diesel Pollution Content
No full textSoil pollution caused by hydrocarbons, such as diesel, poses significant risks to both human health and the ecosystem. The evaluation of soil pollution and various soil engineering applications often relies on the analysis of complex permittivity, encompassing parameters such as dielectric constant and dielectric loss. Various computational models, including theoretical physics-based models, mixture theory models, statistical empirical models, and artificial neural network (ANN) models, have been explored for computing soil complex permittivity and predicting water and pollutant content. Theoretical models require detailed data that is often unavailable, and thus have limited applicability. Mixture models tend to underestimate soil characteristics due to inaccuracies in permittivity estimation of soil phases. While empirical models are widely used, their applicability is restricted to specific soil types, datasets, and locations. ANN models offer promising predictions, accommodating nonlinear phenomena and allowing for missing information and variables. In this study, capacitive electromagnetic electrode sensors were utilized to determine the complex permittivity of soil contaminated with varying levels of diesel at different moisture levels. Theoretical mixture, empirical, and Feed Forward Neural Network (FFNN) models were employed to compute the permittivity of polluted soil based on its phases and to predict the level of diesel pollution. A comparison of these modeling approaches revealed that the FFNN model exhibited the best performance. The ANN model demonstrated superior performance metrics, including a high correlation coefficient and lower mean square error. Specifically, the correlation coefficients for the FFNN model were 0.9942 for training samples, 0.9967 for validation samples, and 0.9977 for test samples. Additionally, the ANN model yielded the lowest mean square error compared to the other three models. Doi: 10.28991/CEJ-2024-010-09-018 Full Text: PD
Flexural Performance of Beams Strengthened with FRP Laminates and Alternative U-Wrap Anchors
No full textPremature debonding is identified as the main failure mode in reinforced concrete (RC) beams strengthened with externally bonded Fiber-Reinforced Polymer (FRP) laminates. This issue leads to the underutilization of FRP materials and needs to be addressed. Research has shown that end anchorage systems can effectively delay/mitigate delamination failures and enhance the performance of strengthened beams. FRP U-wraps are an effective means to prevent debonding failure; however, as open-form anchors, U-wraps cannot always guarantee complete resistance to debonding failures. This study proposes an alternative U-wrapping technique where the ends of the U-wraps are flared and inserted into the concrete substrate. The feasibility and effectiveness of this technique were studied by comparing it with conventional U-wraps. The experimental phase involved testing seven RC beams, each measuring 1.96í—0.15í—0.3 meters, under four-point bending. The results showed that the anchorage technique improved beam performance in terms of load-deflection behavior, failure modes, ductility, and FRP strain. Additionally, finite element simulations were conducted using Abaqus software to assess the effectiveness of the alternative U-wrap scheme. These models incorporated various nonlinear material constitutive laws, including cohesive zone modeling to replicate debonding failures at the CFRP-concrete interface. The numerical predictions were found to be in good agreement with the experimental test data. Doi: 10.28991/CEJ-2024-010-08-01 Full Text: PD
Experimental Study of the Principal Characteristics of Sustainable Micropile Grout Containing Alternative Sands
No full textThe paper discloses a laboratory investigation on employing manufactured sand cement as grout in micropiling works. In practice, to prepare micropile grouts, Portland cement is commonly used. The grout usually consists of natural sand to obtain the strength parameters and value international standards require for micropile construction. It is common knowledge that using concrete and natural sand leaves its environmental footprint. Although there have been numerous attempts to use more environmentally friendly materials, utilizing manufactured sands, particularly for micropile grouting, is a scientific challenge that researchers are still trying to address. The present study investigates the performance of micropile grout mixtures containing manufactured (M) sands, including limestone (L-M) and granite (G-M) rock as replacements for natural sand. For this purpose, laboratory tests, including unconfined compression strength (UCS) and workability tests, were conducted on samples with varying compositions and ratios of L-M and G-M materials. The complementary microstructure and chemical composition analyses were performed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analysis. The laboratory results indicate that the UCS at 28 days of hardening for all M-sand cement mixtures exceeds the minimum standards required values, falling in a range of 40-50.2 MPa. It's noteworthy that the strength of cement grout containing L-M sand was found to be higher than that of G-M sand. The SEM results show the G-M sand grain is rougher than L-M, and the L-M sand grain size is finer than the G-M samples, which causes a decrease in porosity at the interfacial transition zone. Grout workability tests demonstrated that higher water-cement ratios (W/C) led to increased fluidity across all mixtures, with G-M sand resulting in lower flowability than L-M samples. Overall, the results suggest that the proposed mixtures could serve as sustainable alternatives for micropiling, reducing cement content and utilizing alternative, reused materials in grouting mixtures more effectively and sustainably. Doi: 10.28991/CEJ-2024-010-10-019 Full Text: PD
Modeling of the Full-Scale Secondary Sedimentation Basin Using the GPS-X Model
No full textThe secondary sedimentation basin is being modeled in this study for the first time using the GPS-X model instead of the computational fluid dynamics (CFD) model. This study was conducted in the extended-aeration Al-Hur treatment plant that struggles with unstable sedimentation in its sedimentation tank. After collecting and entering the data into the GPS-X model, the model was calibrated and validated, and the results were statistically examined based on R and RMSE. To determine the efficiency of the sedimentation tank, the following scenarios were investigated: 1) testing the efficiency in removing pollutants; 2) conducting state point analysis (SPA); and 3) measuring the concentration of sludge in the layers of the sedimentation basin. Six factors were considered during the sensitivity analysis, namely sludge volume index (SIV), surface area, underflow rate (RAS), pumped flow (WAS), maximum settling velocity, and liquid temperature. The calibration and validation results were within the specified limits, and the secondary sedimentation basin demonstrated high efficiency in removing pollutants, with the analysis point (SPA) obtaining the highest MLSS concentration of 3000 mg/L. The sludge concentrations in the lower layers were 7000 mg/L, while those in the upper layer were 18 mg/L. These results suggest that a lower (100 ml/g) sludge volume index corresponds to a better sedimentation basin efficiency. Increasing the surface area of sedimentation basins can positively affect their efficiency, while increasing waste-activated sludge, maximum settling velocity, and liquid temperature may reduce pollutants and improve the sedimentation process. The GPS-X model is demonstrated as an excellent tool for understanding and predicting the work behavior of sedimentation basins, making this model particularly valuable for the management of sewage treatment plants. Doi: 10.28991/CEJ-2024-010-09-017 Full Text: PD
Enhancement of Expansive Soil Properties by Water Treatment Sludge Ash in Landfill Liners
No full textThis study aims to enhance the suitability of expansive clayey soils for use as landfill liners by incorporating water treatment sludge ash (WTSA). Expansive soils, prone to swelling and desiccation cracking, compromise landfill liner integrity, increasing the risk of groundwater contamination. Local soils often do not meet the requirements for hydraulic conductivity and stability, prompting the use of additives like bentonite. However, bentonite-treated soils still face challenges in tropical regions due to moisture loss and cracking. This research investigates the effects of adding WTSA to bentonite-treated soils to mitigate swelling and shrinkage issues. Several geotechnical tests were conducted, including hydraulic conductivity, free swell percentage, swelling pressure, volumetric shrinkage, and desiccation cracking. Results show that WTSA significantly reduces hydraulic conductivity, free swell percentage, and swelling pressure, meeting the standard requirements for liners (hydraulic conductivity of at least 1í—10-9m/s and volumetric shrinkage of at least 4%). Moreover, WTSA addition reduces desiccation cracking to acceptable levels, demonstrating its potential as an effective reinforcement material. This study introduces an innovative approach to using WTSA, a waste product, as a sustainable alternative to conventional liner materials, reducing environmental impact and enhancing landfill liner performance. Doi: 10.28991/CEJ-2024-010-11-04 Full Text: PD