This study aimed to investigate the effectiveness of an innovative way to reinforce the concrete beams using cross-rod steel bracing under pure torsion. The experimental program consists of casting and testing eighteen concrete beams made of three types of concrete in the form of three groups, with the same dimensions for all beams (200×200×2000) mm. The parameters of the study included concrete types (normal strength, high strength, and steel fiber), as well as the number of internally cross rods (4, 8, 12, 16, 20). The experimental results showed that the number of internally cross-rod reinforcements and concrete type had an effect on ultimate torque, crack width, toughness, and stiffness. The torsional capacity of all concrete beams increased with the increase in internally cross-rod reinforcement. The ultimate torque of normal-strength concrete beams, high-strength concrete beams, and steel fiber concrete beams reinforced with twenty internally cross rods increased (88.34%, 53.20%, and 40.60%), respectively, compared to beams without cross rods in each type of concrete beam. Increasing the internally cross rod in all concrete beams effectively inhibited the development of crack width and improved torsional stiffness, especially in fibrous concrete beams that contained steel fiber. The torsional toughness of all concrete beams increased with the increase of internally cross-rod reinforcement, and it was higher in steel fiber concrete beams. The steel fiber concrete beams reinforced with internally cross-rod steel bracing have better torsional properties compared to ordinary concrete beams and high-strength concrete beams. Doi: 10.28991/CEJ-2024-010-04-06 Full Text: PDF

Steel dampers, specifically steel slit dampers (SSDs), are crucial for enhancing the seismic resilience of buildings by absorbing energy and mitigating damage. SSDs are celebrated for their ability to produce stable hysteretic behavior, owing to the inelastic deformation of their strips, alongside benefits such as lightness, ease of manufacture, and straightforward post-earthquake replacement. This research extensively examines SSD applications, design principles, and innovations in their modeling, optimization, and production processes. The literature highlights SSDs' consistent performance in resisting both compression and tension, their adaptability in strength, ductility, and energy dissipation through modifications in strip configurations and the superiority of non-prismatic and hourglass-shaped designs over traditional options. Numerical analyses have been conducted to assess the effectiveness of non-prismatic slit dampers in comparison to their prismatic counterparts within braced frames. Three distinct braced frame configurations have been analyzed: one with a diagonal brace without a damper, another featuring a uniform prismatic slit damper, and a third incorporating a non-prismatic slit damper with an hourglass shape. The analysis primarily compared these systems' hysteresis behavior, ductility, and energy dissipation capacities. Results indicate a significant enhancement in performance when utilizing non-prismatic slit dampers. Notably, these dampers exhibited a remarkable 69% increase in cumulative energy dissipation compared to prismatic ones. Furthermore, the study reveals that a steel slit damper-braced frame, when equipped with optimally designed slit geometries, can tolerate inter-story drifts in excess of 2% while simultaneously achieving a greater than 12% increase in energy dissipation efficiency. Doi: 10.28991/CEJ-2024-010-04-019 Full Text: PDF

This 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: PDF

Addressing the environmental threat of Polyethylene Terephthalate (PET) waste is critical for sustainable development. Despite PET's prevalence in everyday products, its improper disposal endangers environmental health. This study targets a pivotal gap in current research. PET waste's potential as a sustainable building material will be thoroughly evaluated, focusing on whether recycling PET waste is feasible. In the construction industry, it can be a substitute for natural sand and an additive in cement. This study contributes to a dual-purpose solution: mitigating environmental pollution and innovating in construction material science. The systematic literature review (SLR) delves into existing studies, focusing on PET's impact on concrete properties when substituting natural sand at ratios of 5% to 20% and as a cement additive at 0.5% to 2% by weight. The findings revealed that up to a 10% PET replacement enhances compressive strength, highlighting a sustainable pathway for construction practices. However, replacements above 10% show a reduction in strength, indicating an optimal substitution threshold. Moreover, incorporating PET additives at 1% by cement weight optimizes flexural strength, underscoring the material's viability in enhancing structural integrity. This study sheds light on PET waste's application in reducing environmental impact and proposes a viable, eco-friendly alternative for construction materials. The recommendation for further research underscores the necessity to refine PET's application in construction, aiming to bridge the knowledge gap and encourage sustainable future innovations. Doi: 10.28991/CEJ-2024-010-04-020 Full Text: PDF

The addition of natural fibers in the elaboration of concrete pastes has increased as an innovative alternative for the development of more ecological and environmentally friendly constructions. The objective of this research is to incorporate natural fiber residues from palm leaves and mango stone impregnated with used engine oil (UEO) in the cement matrix to improve the mechanical and electrochemical properties of reinforced concrete. Samples with fiber percentages of 0.2% and 0.4% with respect to the weight of the sand with a length of 10 mm were fabricated. Their properties, such as workability, air content, porosity, and compressive and flexural strength, were analyzed. To understand the corrosion rate of the steel bars, electrochemical techniques of corrosion potential, electrochemical noise, linear polarization resistance, and electrochemical impedance spectroscopy were applied to cubic samples exposed in a 3% sodium chloride saline environment for 365 days. The experimental results showed a positive effect on the corrosion phenomenon with the UEO and mango fiber treatment, decreasing the corrosion rate due to the formation of a protective film at the steel/concrete interface. Doi: 10.28991/CEJ-2024-010-04-02 Full Text: PDF

Construction projects frequently encounter challenges such as stagnant productivity, excessive waste, cost overruns, and delays, contributing to sustainability issues. In response to these issues, Lean Construction (LC) has emerged as a methodology aimed at eradicating inefficiencies and wasteful practices. However, the construction industry has been slow to embrace LC, primarily due to a lack of comprehensive evaluations regarding its real-world effectiveness. This study seeks to thoroughly assess the effectiveness of LC when implemented in construction projects in Pakistan. The research involved conducting a survey among experts in the construction industry, utilizing a comprehensive questionnaire to evaluate the extent of LC adoption and its impact on construction project performance. The collected data underwent rigorous statistical analysis to ascertain the influence of LC practices on project outcomes. To validate the survey results, the study selected five case study projects for in-depth analysis. These case studies assessed how well the projects adhered to LC principles and examined the resulting effects on project delays, cost overruns, quality issues, rework, and health-related concerns. The findings consistently confirmed that a higher level of adherence to LC principles led to significant reductions in project delays, cost overruns, quality issues, and health-related problems. This analysis strongly supports the notion that a more extensive adoption of LC practices results in substantial improvements in project performance. By presenting these compelling results, this study offers valuable insights to the construction industry, providing a clearer path for the effective integration of LC practices. Doi: 10.28991/CEJ-2024-010-04-09 Full Text: PDF

In an extensive exploration of microplastics within soil environments, our study aims to investigate the presence, spread, and ecological impact of microplastics in soil, focusing on Makassar City, Indonesia. Using a Sinher binocular digital microscope, we visually examined soil samples in Petri dishes, measuring microplastic sizes with Image-J software. Fourier-transform infrared (FTIR) spectroscopy was also employed for additional identification and analysis of polymer compositions. Our research uncovered a widespread presence of microplastics across diverse soil types and land uses, including residential, fishpond, agricultural, landfill, coastal, and bareland areas. The concentration of these microplastics was found to be between 16.6 to 21.9 particles/gram, showing consistency across most land uses, with some variations in coastal areas. We noted a significant variety in microplastic forms, predominantly fragments and films, across the different land uses. A wide range of colors was observed, including blue, green, red, and transparent. Polyethylene (PE) and polypropylene (PP) were identified as the predominant polymers. Our study highlights the non-uniform distribution of microplastics in soil, suggesting potential significant impacts on soil organisms and the wider ecosystem. These findings underscore the critical need for more comprehensive research on the ecological implications of microplastics in soil environments. Doi: 10.28991/CEJ-2024-010-04-017 Full Text: PDF

This study classified surface water quality in Can Tho city using the Eutrophication index, Harmony Degree Equation (HDE), and Technique of Order Preference by Similarity to Ideal Solution (TOPSIS). Water quality data were collected in two seasons at 38 locations with 18 parameters, including temperature, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), nitrite (N-NO2-), nitrate (N-NO3-), ammonium (N-NH4+), orthophosphate (P-PO43-), Fe, F-, Pb, As, Hg, coliform, chlorine-, and phosphorus-based pesticides. Water quality parameters are compared with national technical regulations on surface water quality (QCVN 08-MT:2015/BTNMT). The HDE method based on entropy weight has been applied to evaluate the comprehensive harmony degree of water quality for various purposes. In addition, the TOPSIS was also used to rank water quality at each location and determine the priority level that required mitigation and treatment solutions. Surface water quality in the study area had low dissolved oxygen content and was contaminated with TSS and coliform in both seasons. Water quality in the rainy season tends to decrease compared to the dry season. Based on HDE results, water quality in the study area in the dry season was assessed as suitable for domestic activities (needs treatment), irrigation, and navigation (HDII = 0.922), while the rainy season was suitable for irrigation and navigation (HDIII= 1.00). Moreover, surface water in the study area was in a state of potential eutrophication (EI > 0), in which eutrophication was higher during the dry season. The SW25 and SW28 were the most seriously eutrophic in the dry and rainy seasons, respectively. TOPSIS analysis indicated that SW22 and SW28 need treatment measures in both seasons; furthermore, SW2-SW4 (dry season) and SW23 (rainy season) also need appropriate management and impact mitigation solutions. SW4 was affected by the most significant seasonal impacts, which have high priority in the dry season and are lowest in the rainy season. Therefore, future studies are needed to identify specific sources of variation at these locations to reduce impacts. The study results provide helpful information for the decision-making process and water quality management. Doi: 10.28991/CEJ-2024-010-04-012 Full Text: PDF