Civil Engineering Journal
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2007 research outputs found
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Utilizing GIS and Machine Learning for Traffic Accident Prediction in Urban Environment
No full textTraffic accident prediction is crucial to preventive measures against accidents and effective traffic management. Identifying hotspots can facilitate the selection of the most critical survey points to note the contributing features. In this research, an effort has been made to identify hotspots and predict traffic accident occurrences in an urban area. Accident data was obtained from the Rescue 1122 Emergency Services of Faisalabad, and hotspots were identified using Moran's I in ArcGIS. Results showed that most hotspots were located around the General Transport Stand (GTS) area due to the maximum number of road users. The temporal investigations showed that the accident occurrence was significant from 1 to 2 p.m. The identified hotspots were further investigated by conducting a field survey. Essential features such as road geometric features, road furniture, and traffic data were used for developing Machine Learning Algorithms for accident prediction. Using Computer Vision, traffic data was extracted from recorded videos. Random forest, linear regression, and Decision tree algorithms were developed using Python in the Jupyter Notebook environment. The decision tree algorithm showed a maximum accuracy of 84.4%. The analysis of contributing factors revealed that road measurements had the maximum effect on accident occurrence. Doi: 10.28991/CEJ-2024-010-06-013 Full Text: PD
M-N Interaction Diagrams of RC Columns Strengthened with Steel C-Sections and Battens
No full textDue to design errors and changes in the use of buildings, reinforced concrete (RC) columns must often be strengthened to support additional live loads. The column must be designed to withstand both axial loads and bending moments, and an interaction diagram is necessary to demonstrate the column failure. The most common technique for strengthening RC columns uses a steel jacket consisting of four steel angles and battens. In this study, another strengthening technique was proposed that uses two steel C-sections with steel battens. A new approach for constructing an axial force-bending moment interaction diagram for RC columns strengthened with steel C-section jackets using an analytical model based on the plastic stress distribution method was introduced. A finite element (FE) model was created using Abaqus software, and the FE results were consistent with the experimental and analytical results. The analytical and FE results showed that this strengthening method was effective and increased the axial load and bending moment capacities of the strengthened columns. This increase was explained by the confining effect of the steel jacket and the ability of the steel C-sections to withstand a large part of the applied load. This approach offers an effective and economical solution for the reinforcement of RC columns and provides a reliable and safe option for structural engineers. Doi: 10.28991/CEJ-2024-010-06-016 Full Text: PD
Integration of Blockchain-Enabled Smart Contracts in Construction: SWOT Framework and Social Network Analysis
No full textThe construction sector, one of the most ancient industries globally, holds a crucial role in the progress and development of societies. However, it faces persistent productivity and efficiency challenges, rendering it a relative setback when compared to other sectors. In the ever-evolving landscape of the construction industry, characterized by complex projects, numerous stakeholders, and intricate contractual agreements, the integration of emerging technologies presents an unprecedented opportunity for transformation. Smart contracts (SCs), underpinned by blockchain (BC) technology, hold the potential to streamline and revolutionize traditional construction processes. Current literature shows a lack of comprehensive quantitative understanding of how Blockchain-enabled Smart Contracts (BSC) can affect the construction sector. To address this gap, the authors have (1) conducted a systematic keyword analysis of literature on SC in construction from Scopus and Web of Science (WoS) databases; (2) conducted a strengths–weaknesses–opportunities–threats (SWOT) analysis of BSC's adoption in the construction industry from 174 peer-reviewed papers; (3) identified a holistic list of 72 factors steering BSC adoption in construction, categorized into the 4 aspects of the SWOT framework; (4) performed social network analysis (SNA) to quantitively assess the literature in terms of the identified factors; and (5) conducted clustering analysis to categorize combination of factors frequently highlighted in research publications into common groups. This research offers a comprehensive and methodical evaluation of the potential advantages, applications, and challenges associated with integrating BSC in the construction industry. The findings of SNA and clustering reveal a notable lack of investigation into certain combinations of factors in existing academic research. This disparity and the ensuing knowledge gaps may affect SC's adoption in the construction sector. To this end, this study equips stakeholders with the insights necessary to make informed decisions in this rapidly evolving sector and contributes to a roadmap for future BSC construction-related research. Doi: 10.28991/CEJ-2024-010-05-020 Full Text: PD
Load Capacity and Bending Strength of Double-Acting Friction Stir Welded AA6061 Hollow Panels
No full textAluminum alloy hollow panels are essential components in both civil and mechanical structures, such as building floors or large vehicle platforms. They enhance rigidity while staying lightweight and conserving material volume. In its application, this panel must be joined using welding methods. One common issue encountered in aluminum welding is the formation of porosity defects. Solid-state welding methods like Friction Stir Welding (FSW) can be a solution to address this problem. The FSW joining process on hollow panels cannot be completed in one welding operation due to their thickness. The FSW process must be performed on both surfaces, which requires a relatively long time. Therefore, FSW needs to be developed into a Double-acting FSW that utilizes two tools simultaneously. These two tools introduce two sources of heat input, pressing force, and friction-stirring, resulting in a novel response that needs further research. This study delves into the impact of welding speed variations in Double-Acting FSW on the load capacity and bending strength of AA 6061 hollow panel joints. Welding speeds of 20, 30, and 40 mm/min were tested alongside rotational speed (1500 rpm), tilt angle (2°), and shoulder diameter (24 mm). It was discovered that reducing welding speed enhances both load capacity and bending strength. Notably, specimens welded at 20 mm/min exhibited a load capacity of 15.61 kN and bending strength of 52 MPa, highlighting the potential of slower speeds for superior weld performance. Doi: 10.28991/CEJ-2024-010-08-018 Full Text: PD
Experimental and Numerical Research on the Behavior of Steel Columns with Circular Hollow Cross Sections
No full textA circular, hollow tubular steel column is introduced for experimental and analytical analysis in this study. A series of axial compression tests for the variation of static schemes are reported in this study. All theoretical, numerical, and experimental analyses are based on the European Standards for the steel structure, respectively EN 1993-1-1. The experimental models of steel columns are conducted on actual steel columns with a length of 3000 mm and a circular hollow section of 114.3/2.8 mm. To assess the behavior and stress values of the columns, various schematically supported systems are modeled, starting from the axial-centered columns to the symmetrical eccentric load and asymmetrical loaded columns. 3D modeling of the steel columns using the finite element program SEISMOSOFT is also developed for such elements. The accuracy of the model is compared with the experimental results using numerical analysis by the finite element method. Finally, the numerical comparison of the results provides a recommendation for the engineers regarding the design and construction of such columns. Doi: 10.28991/CEJ-2024-010-05-014 Full Text: PD
Optimizing Landfill Site Selection Using Fuzzy-AHP and GIS for Sustainable Urban Planning
No full textCareful landfill selection with minimal environmental impact is vital for urban planners. This study aims to identify suitable sites for controlled landfills using Fuzzy-AHP integrated with Remote Sensing and GIS, considering a 20-year projection of population and solid waste generation. Initially, twelve sub-criteria were identified, grouped into environmental, socio-economic, and physical categories, and then weighted using paired comparison matrices involving nine experts. The sub-criteria were rasterized and classified into four suitability levels. The weighted overlay of sub-criteria maps generated a territorial suitability model. Within the Alto Utcubamba Commonwealth (Amazonas, Peru), 0.069%, 41.70%, 66.934%, 0.20%, and 12.4% of the territory are suitable, moderately suitable, less suitable, unsuitable, and restricted, respectively, for landfill establishment. Subsequently, 16 highly suitable sites were selected based on the required area (S4 polygons ≥ 0.505 ha) in line with the projected solid waste generation over 20 years. Of the 16 selected areas, only 15 met the shape index. The model showed high accuracy (AUC = 0.784) during validation. Furthermore, this study provides a comprehensive framework for making decisions about waste management in developing countries, enhancing understanding of key factors in selecting landfill sites. It also offers a deeper insight into global and local factors that determine the suitability of landfill sites. Doi: 10.28991/CEJ-2024-010-06-01 Full Text: PD
Performance of NSM GFRP Retrofitted Postfire RC Slabs Under Monotonic and Cyclic Loadings
No full textThis study investigated the performance and mechanical properties of NSM GFRP retrofitted postfire RC slabs under monotonic and cyclic loadings. Experiments were conducted for eight RC slabs exposed to different fires. These postfire slabs were retrofitted with NSM GFRP bars, which were then monotonically and cyclically loaded until failure. The results indicated that the control slab failed in flexure, with steel yielding and a main mid-span crack. NSM GFRP retrofitted postfire slabs failed by either crushing of compressive concrete or rupture of GFRP bars. The tested slabs were characterized by bi-linear behavior. NSM GFRP retrofitting improved the yield and ultimate loads of postfire slabs by 47.2% and 116.4% on average, respectively. Fire duration was confirmed to be a main factor that significantly reduced the elastic stiffness of NSM GFRP retrofitted postfire slabs by 60.9% for 60 min of fire. The average plastic-to-elastic stiffness of NSM GFRP retrofitted postfire slabs was 0.132, which was 32 times that of the control slab. The cyclic loading effect caused substantial stiffness degradation of NSM GFRP retrofitted postfire slabs. The average stiffness degradations were 10.6% and 7.2% for original and NSM GFRP retrofitted postfire slabs, respectively. However, the cyclic loading effect caused negligible strength degradation. The combination of increasing fire duration and the cyclic loading effect significantly decreased ductility. Theoretical analyses were carried out to estimate the yield moments of slabs. The analytical equation demonstrated its accuracy in estimating the yield moment capacity of postfire RC slabs without and with NSM GFRP retrofitting. Doi: 10.28991/CEJ-2024-010-06-017 Full Text: PD
Experimental Investigation on Pervious Recycled Aggregate Concrete Made of Waste Porcelain
No full textThe current study examines the physical, mechanical, and durability of eco-efficient pervious concrete produced with partial and complete substitutions of natural aggregate (NA) by recycled aggregate (RA) waste from demolished concrete and porcelain. The experimental investigation assessed the workability (slump test), compressive strength, flexural strength, and tensile strength along with the concrete's water permeability, impact, and abrasion resistance. Seven mixes were examined; the first is a control mix with natural aggregate, and the other six are made with various RA ratios, including 30%, 70%, and 100%. The sand was also fully replaced by waste porcelain, even though the ratio of sand used in pervious concrete was low. The results revealed that using waste concrete and porcelain adversely affected the workability of fresh pervious concrete mixes, reducing it by approximately 14%. Furthermore, a decrease in the strength of pervious concrete was noticed, especially in the splitting tensile strength, where the reduction reached 32%. Moreover, the impact resistance of pervious concrete made with RA reduced by 29% compared to that made with NA; the same applies to durability, with an increase of 20% in weight loss. On the other hand, using both recycled concrete and recycled porcelain improved the permeability of the pervious concrete, which reached 30%. Pervious concrete made with waste concrete and porcelain can be an acceptable alternative to that made from natural aggregate due to its improved water permeability and positive environmental impact. However, further investigation is important to consider strength and durability enhancement. Doi: 10.28991/CEJ-2024-010-09-08 Full Text: PD
Flexural Performance of a New Composite Double PSSDB Slab System Filled with Recycled Concrete
No full textThis study investigated the flexural performance of a composite floor system utilizing a profile steel sheet dry board (PSSDB) that was enhanced by adding an additional layer of profile steel sheet (PSS) and infilled with both normal and recycled concrete materials. This improved system is referred to as the double-profile steel sheet dry board (DPSSDB) system. The new DPSSDB concept was proposed to reduce fabrication costs, overall weight, and the depth of the composite floor system compared to traditional composite beam-slab systems. To assess the impact of the additional PSS layer, ten full-scale specimens of both PSSDB and DPSSDB were subjected to four-point static load tests. Additionally, the study investigated the use of lightweight recycled aggregates such as crumb rubber and expanded polystyrene as partial replacements for the aggregates in the infill concrete. The results demonstrated that the DPSSDB system exhibited a 112–170% increase in bending capacity compared to the PSSDB specimens. Partial replacement of concrete aggregates with lightweight recycled materials up to 50% had only a marginal effect on the bending behavior of both PSSDB and DPSSDB specimens compared to those filled with normal concrete. However, replacing 75% of the aggregate with recycled materials led to a 27% reduction in the flexural bending capacity of the DPSSDB specimens compared to those infilled with normal concrete. Additionally, a new method (theoretical equation) was developed to predict the ultimate moment strength (flexural) of the novel DPSSDB composite slab system, which aligned well with the experimental results, achieving a deviation percentage of 0.81% and a mean value of 0.965a. Doi: 10.28991/CEJ-2024-010-12-03 Full Text: PD
Behavior of Axially Loaded Concrete Columns Reinforced with Steel Tubes Infilled with Cementitious Grouting Material
No full textThe paper presents a novel method of reinforcing concrete columns using small-diameter steel tubes instead of traditional steel bars. The researchers conducted experimental investigations on twelve mid-scale circular concrete column specimens, which were divided into two groups consisting of six specimens each: short and long columns. Two of the specimens in each group were reinforced with steel bars, while the remaining four were reinforced with steel tubes filled with cementitious grouting material. The study proposed two concepts for cementitious grouted steel-tube reinforcement. The first concept utilized steel tubes with equivalent net areas to the steel bar areas used in the reference column, while the second concept used steel-tube reinforcement with the same diameter as the steel bars in the reference column. Nonlinear Finite Element (FE) analyses were conducted on experimental specimens using ABAQUS software. The results showed that using steel tubes with an area equivalent to that of steel bars instead of conventional columns increased the bearing capacity of reinforced concrete columns by 17%. Moreover, using steel tubes whose area matched 30% of the steel bar area achieved a bearing capacity of about 81% of the conventional concrete columns. The experimental and FE analysis findings indicate that this methodology can increase the bearing capacity of reinforced concrete columns when compared to traditional methods. The axial load-axial displacement curves, axial load-axial strain curves, and failure load of the FE model all demonstrated good convergence with the experimental data. Doi: 10.28991/CEJ-2024-010-02-017 Full Text: PD