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Construction Project Delay Risk Assessment Based on 4M1E Framework and Afghanistan Situation
No full textIn the realm of construction project management, delays present a significant impediment, particularly within complex socio-political contexts such as Afghanistan. This study endeavors to elucidate the multifaceted nature of construction project delays in Afghanistan, employing the 4M1E (Man, Machine, Material, Method, and Environment) framework to conduct a comprehensive risk assessment. The research methodology entailed the development of a structured questionnaire grounded in an extensive review of pertinent literature, targeting 30 recognized causes of project delays. This instrument was administered to a representative sample of 144 professionals across the Afghan construction industry spectrum, including clients, consultants, and contractors. Analytical rigor was applied through the deployment of frequency, severity, and importance indices to evaluate the collected data. This analysis culminated in the distillation of ten paramount delay risk factors, encapsulating elements such as governmental policy stability modifications in project scope and design alongside delays in material testing and approval processes. A comparative dimension was incorporated to benchmark these findings against global standards, thereby enhancing the robustness of the study's conclusions. Moreover, the research delineates the congruence and discordance among different respondent cohorts, bolstering the integrity of the identified delay factors through a validation of internal consistency and reliability. The strategic application of the 4M1E framework, contextualized within the Afghan construction landscape, furnishes pivotal insights for stakeholders, equipping them with a nuanced understanding necessary for the proactive mitigation of delay risks. The implications of this study are far-reaching, promising to augment project completion efficiency, budget adherence, and overall project success, with particular resonance for environments paralleling the intricacies of Afghanistan. Doi: 10.28991/CEJ-2024-010-01-06 Full Text: PD
Applying Harmony Degree Equation and TOPSIS Combined with Entropy Weights in Surface Water Classification
No full textThis 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: PD
Analysis and Prediction of Rainfall with Oceanic Nino Index and Climate Variables Using Correlation Coefficient and Deep Learning
No full textThis article presents the relationship between the Oceanic Nino Index (ONI) and monthly rainfall on the southern and eastern coast of Thailand, specifically in Narathiwat, Pattani, and Yala provinces, where influences have been commonly observed. This research aims to study the relationship between the Oceanic Nino Index (ONI) and monthly rainfall to develop a model for predicting monthly rainfall. Despite previous related research, there has been no in-depth study on the relationship between the Oceanic Nino Index (ONI) and monthly rainfall in areas adjacent to the sea. The correlation coefficient was used to determine the relationship, revealing that the ONI value is significantly correlated with the amount of rainfall in the current month and the following month. This correlation paved the way for developing a model to predict monthly rainfall. Multiple linear regression, recurrent neural networks, and long short-term memory models were employed for this purpose. The study found that utilizing a recurrent neural network yielded the best prediction efficiency, with Mean Absolute Error (MAE) values of 112.76 mm for Narathiwat province, 81.06 mm for Pattani province, and 97.67 mm for Yala province. Doi: 10.28991/CEJ-2024-010-05-01 Full Text: PD
GGBFS and Red-Mud based Alkali-Activated Concrete Beams: Flexural, Shear and Pull-Out Test Behavior
No full textGeopolymers and antacid-enacted fasteners have accumulated critical interest as promising development and fixing materials because of their exceptional properties. Also, they bring about less contamination contrasted with regular concrete cements. Geopolymers address a clever class of suggested restricting materials blended through the basic enactment of bountiful aluminosilicate materials. The usage of geopolymer materials from side effects offers a critical decrease in carbon impression and yields positive natural effects. Geopolymer is progressively recognized as a plausible substitute for OPC concrete. In this review, sodium-based antacid activators, especially sodium metasilicate (Na2SiO3), were used for different blend extents. The boundaries researched included NaOH arrangements with a grouping of 8 M, alongside a Na2SiO3/NaOH proportion of 1. This paper evaluates the fundamental characteristics of geopolymer cement beams, employing red mud and GGBFS in powdered form as complete replacements for traditional concrete. Six bar specimens are tested under a two-point static loading condition, all cured at room temperature under ambient conditions. Of the six beams, three were exposed to flexural conduct testing with a molarity of 8 M, while the excess three beams were tried for shear conduct. The outcomes of testing geopolymer beams subjected to shear and bending loads indicated that the beams incorporating aluminum slag performed better than those incorporating blast furnace slag. Both types also demonstrated promising results compared to beams incorporating OPC, highlighting their potential environmental benefits compared to cement use. Doi: 10.28991/CEJ-2024-010-05-09 Full Text: PD
Corrosion Resistance of Reinforcing Steel in Concrete Using Natural Fibers Treated with Used Engine Oil
No full textThe 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: PD
Assessing the Impact of Adverse Weather on Performance and Safety of Connected and Autonomous Vehicles
No full textConnected and Autonomous Vehicles (CAVs) might significantly enhance the transportation system by improving safety, accessibility, efficiency, and sustainability. However, a major challenge lies in ensuring CAVs can operate properly under diverse weather conditions, which have already proven to impair human driving capabilities. This pioneering study aims to bridge a crucial research gap by comprehensively assessing the performance of CAVs on traffic operations and safety across varying weather scenarios. Using microscopic traffic simulation in VISSIM and the Surrogate Safety Assessment Model (SSAM), this study evaluates key metrics, including average speed, delay, number of stops, travel time, and number of conflicts for different CAV market penetration rates. The analysis spans 21 scenarios under clear, light rain, heavy rain, and foggy conditions within a selected urban corridor in the United Arab Emirates. The results showed that the average speed rose by 55% in clear weather, while the average delay, the number of stops, travel time, and the number of accidents decreased by 50%, 50%, 95%, and 68%, respectively. In light rain, the average speed improved by 43%, while the average delay, number of stops, travel time, and the number of accidents reduced by 43%, 56%, 96%, and 74%, respectively. The average speed increased by 82% under heavy rain, while the average delay, the number of stops, the travel time, and the number of accidents all fell by 62%, 68%, 96%, and 74%, respectively. In fog, the average speed rose by 32%, while the average delay, average stop number, travel time, and the number of accidents decreased by 33%, 47%, 90%, and 83%, respectively. Overall, this paper highlights the need for resilient CAV systems adaptable to diverse environmental conditions. It helps advance the understanding of how CAVs can be optimized for safety and efficiency in urban settings, contributing to sustainable transportation solutions. It provides insights into the challenges and innovative approaches for CAV deployment in adverse weather, laying a foundation for future research and the broader implementation of these technologies in urban mobility. Doi: 10.28991/CEJ-2024-010-09-019 Full Text: PD
Investigation of the Mechanical Behavior of Full-Scale Experimental Bugis-Makassar Timber House Structures
No full textThe Sulawesi region is located at the confluence of a smaller Philippine plate and three major global plates, namely the Indo-Australian, Pacific, and Eurasian. This strategic location makes Sulawesi and the surrounding earthquake-prone region in Indonesia. Recognizing the seismic vulnerability of this region, various measures, such as the use of houses on stilts, have been explored to enhance earthquake resistance. These structures are designed to avoid direct exposure to seismic energy, according to several reports on Indonesian earthquakes. In the last two years, an in-depth investigation has been carried out to analyze the behavior and resistance of Bugis Traditional Houses to earthquakes. Although simulation and computational studies are still in progress, the results show that Bugis-Makassar House on stilts maintains an elastic state with a high level of performance. Therefore, this study aimed to investigate the mechanical behavior of Bugis-Makassar stilt house structures using full-scale tests. During the investigation, experimental testing was conducted using house specimens measuring 1.5í—2.3 m in the laboratory. A cyclic lateral loading analysis was performed using ISO 16670-2003 as a guide. The results showed that cyclic lateral loads caused house structures to sway, while the timber experienced minimal damage. Both the hysteresis energy, EH to EI, and the energy conversion ratio, GPE to ESE (ER), were found to be approximately balanced. This equilibrium suggested that seismic energy can be cyclically stored and released to reduce damage to structural elements. Doi: 10.28991/CEJ-2024-010-06-04 Full Text: PD
Strength and Acid Resistance of Mortar with Different Binders from Palm Oil Fuel Ash, Slag, and Calcium Carbide Residue
No full textThis study deals with the use of ground palm oil fuel ash (GPOFA) in combination with ground granulated blast furnace slag (GGBFS) and ground calcium carbide residue (GCR) to produce the binary and ternary binders-based alkali activated mortar. The appropriate content of materials in each binder type was determined as a function of compressive strength. The results revealed that both GPOFA:GGBFS and GPOFA:GCR binders had an optimum blending ratio of 70:30 wt%, while the GPOFA:GGBFS:GCR binder was 55:30:15 wt%. An alkaline catalyst of NaOH was admixed to the best mixture in each binder type to stimulate the mortar's compressive strength. The sulfuric acid (H2SO4) resistance of the mortar in terms of weight change was also examined. The addition of 1M NaOH in both binary and ternary binders could enhance the compressive strength and H2SO4 resistance of the mortar. The highest compressive strength and lowest weight change due to soaking in H2SO4 solution were found in the ternary binder mortar with a 1 M NaOH. The mortar with GCR immersed in H2SO4 solution resulted in an increased weight, which was different from that of the mortar without GCR. The microstructural analysis of the alkali-activated pastes indicated more reaction products than in the case of the pastes without alkali activator. However, a higher concentration of 2 M NaOH resulted in a poor microstructure, which had a negative effect on the compressive strength and H2SO4resistance. Doi: 10.28991/CEJ-2024-010-07-08 Full Text: PD
Research into Uranium Characteristics and Content in a Pregnant Solution During Leaching with Oxygen Saturation
No full textThe 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
Managing Green and Sustainable Technologies: Climate-Informed Corrosion Prediction for Steel Structures
No full textThe 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