Civil Engineering Journal
Not a member yet
2007 research outputs found
Sort by
Comparative Evaluation of Compressive Strength in Earth Blocks Enhanced with Natural Fibers
No full textPortland cement is a key component in the production of concrete blocks; however, its production has an extensive carbon footprint that contributes towards climate change. In addition, the availability of aggregates is also often challenging and, as such, leads to production delays of concrete blocks, which ultimately causes delays in the completion of construction projects and constant price increases. The price increase of construction materials such as concrete blocks tends to affect the quality of houses being constructed in rural communities of the Pacific Island Countries (PICs), and this calls for the development of a low-cost alternative to ensure housing quality is not compromised. This project is being carried out to develop earth blocks as an environmentally friendly and sustainable substitute for concrete blocks that are widely used in the construction industry. Coir (derived from coconut fibers) and bamboo fibers were incorporated into these blocks as reinforcement materials, aiming to achieve the same level of strength required for use in construction. Additional adhesion of the earth block was provided by the usage of cement. The earth blocks were cured for 7, 14, and 28 days, after which they were subjected to various tests, including a compressive strength test, water absorption test followed by wet compressive strength test to compare its performance to ensure it has sufficient strength for it to be introduced into the market as a more eco-friendly, low-carbon-emission, and cost-effective construction material. The maximum compressive strength obtained during the test was 3.24 MPa. Following a comprehensive analysis of the data attained, the composition of 15% cement and 0.75% bamboo fiber emerges as the most ideal choice for creating marketable earth blocks. This composition strikes a balance between providing adequate strength and ensuring minimal reduction in overall strength when the blocks are exposed to wet conditions. Doi: 10.28991/CEJ-2024-010-10-013 Full Text: PD
Flexural Behavior of Reinforced Concrete Beams with Steel-Plate Reinforced Vertical Opening
No full textThe structural response of simply supported Reinforced Concrete (RC) beams with square vertical openings is investigated in this work. Studies were conducted using seven specimens of RC beams, with the aim of comparing beams with vertical openings to those without. Meanwhile, the other beams featured carefully positioned square openings. Note that one of these beams served as the control and had no openings. Each beam was the same length (1400 mm) with a 180í—120 mm cross-section. Two-point loads were applied over a span of 1200 mm throughout the testing method, with a central load placed 300 mm from the ends. The openings were positioned in the middle of the span and came in three different widths: 20, 40, and 60 mm. Openings were made using either 1.5 mm thick square steel tubing or none at all. The major goal of this study was to determine whether the steel tube could compensate for the decrease in beam strength and the impact of decreasing beam cross-section (producing opening). Correspondingly, the beam ultimate load was found to decrease by 15.75%, 24.2%, and 32.5% for opening widths of 20 mm, 40 mm, and 60 mm, respectively, as the opening width increased. On the other hand, the performance gain for beams strengthened with steel plates when steel tubes were used was 11.78%, 12.14%, and 13.28% for the respective opening widths. Doi: 10.28991/CEJ-2024-010-09-04 Full Text: PD
Evaluation of Tidal Energy Potential Using a Two-Way Tidal Energy Model
No full textTidal energy is a renewable energy source that provides sustainable energy through the utilization of tidal differences, making it a very promising option. This study examines a more effective tidal energy reservoir model by building a 1:100 scale prototype in the laboratory with several predetermined variations, namely an earthen pond (100, 80, and 60 cm), and flow holes (1.5, 1, and 0.5 cm) with initial tidal height differences of 10 cm, 15 cm, and 20 cm. The model uses a 6-hour time period, which corresponds to a semidiurnal tidal model. The results showed that the highest energy output was 281.84 kWh, achieved with a 1.5 cm flow hole, 20 cm tidal height difference for the initial condition, and 80 cm pond width. For a 1 cm flow hole, the outputs were 1774.8 kWh and 1803.78 kWh for 15 cm and 20 cm tidal height difference for the initial condition with a pond width of 100 cm. Meanwhile, the 0.5 cm flow hole produces potential energy outputs of 2623.8 kWh and 2611.4 kWh for different tidal heights of 15 cm and 20 cm for the initial condition with a pond width of 100 cm. Better model performance can be connected to a mini generator to validate the energy generated from the designed prototype model. Doi: 10.28991/CEJ-2024-010-09-016 Full Text: PD
Vibration Control of Corrugated Steel Web Box Girder Bridge with Friction Pendulum Isolation
No full textIn order to investigate the feasibility and applicability of friction pendulum bearings for vibration control of large-span space beam-arch bridges with corrugated steel web box girders, taking the Huian Yellow River Bridge in Guide County, Qinghai Province, China, as an example. A three-dimensional calculation model of the friction pendulum isolation space beam-arch composite bridge with a corrugated steel web was established by MIDAS, the modal analysis was carried out, and the damping effect of the friction pendulum isolation bridge was investigated using the response spectrum and the time history analysis methods; the influence of the design parameters of the friction pendulum isolation on the reduction effect was further analyzed. The results show that the friction pendulum isolation improves the stress conditions of both the girder and the pier and reduces the displacement and acceleration of the pier top, as well as reduces the acceleration of the girder, and the damping ratio is more than 50%. The optimal dynamic coefficient of friction and the radius of curvature for the corrugated steel web composite bridge are 0.04 and 3.0 m, respectively. Friction pendulum isolation has a good seismic absorption effect and provides an effective way for the seismic control of the corrugated steel web composite bridge. Doi: 10.28991/CEJ-2024-010-10-01 Full Text: PD
Evaluating Axial Strength of Cold-formed C-Section Steel Columns Filled with Green High-performance Concrete
No full textConcrete-filled steel tube (CFST) columns that experience outward local buckling under high axial stress remain a significant concern, particularly when thin steel sections are used, as opposed to semi-compact and compact sections. This study investigated the performance of column systems by comparing single- and double-C-section configurations with both hollow and concrete-filled designs. Two types of infill materials were investigated: normal concrete and recycled material concrete, which included 10% waste glass powder as a cement replacement, 8% black high-density polyethylene beads as a sand substitute, and 10% pumice stone as coarse aggregate. To enhance the strength of the proposed CFS column, steel strips and screws were used to connect the flanges of the C-sections. Nine columns were tested experimentally under static axial load. Additionally, finite element analysis software was used to model and evaluate the effects of parameters beyond those investigated in the tests. The results indicated that the load capacity of the double face-to-face section was approximately 3% higher than that of the double back-to-back section. The addition of steel strips, used to connect the lips of the C-section flanges, enhanced the axial strength of the column by approximately 2% compared with the unstrengthened corresponding specimen and delayed buckling in the most vulnerable areas. Furthermore, the recycled infill concrete material had a minimal impact on the axial performance of the analyzed CFS columns compared to the control concrete, with a difference of less than 2.2%. The findings confirm that recycled waste material concrete can achieve performance comparable to that of the conventional concrete. Doi: 10.28991/CEJ-SP2024-010-014 Full Text: PD
Kinematic Seismic Isolation System with Magnetic Dampers
No full textThe aim of this study is to experimentally and theoretically investigate the behavior of a three-story fragment of a frame building constructed using the PGF-SIKF system”Prefabricated girderless frame with seismic-isolating kinematic foundations. Magnetic dampers are employed at the support level. The novelty of the research lies in the combination of a girderless frame with kinematic foundations and innovative magnetic dampers. The experimental research method involved loading the system with horizontal static force using a stationary winch, followed by the release of the load. Vibration measurements were recorded using a digital measurement system. The normative live load was simulated by applying additional static load. It was determined that the oscillation period varies between 1.8 and 2.1 seconds, depending on the amplitude of the impact. The dissipative characteristics of the seismic isolation system were obtained, with acceleration values during the testing phases ranging from 95 to 177 cm/s². The experimental results confirmed that the building fragment showed no visible damage. The logarithmic decrement of oscillations was found to range between 0.08 and 0.16. Theoretical studies involved calculations based on a sample of 14 real accelerograms, with parameters corresponding to the magnitudes of local earthquakes (M=6), the maximum magnitude expected in Shymkent. The main result is the reduction of seismic loads achieved by using kinematic foundations in the girderless frame system. It was established that, under 7-8 intensity seismic events, the average displacements at the foundation level will not exceed the experimental values. Doi: 10.28991/CEJ-2024-010-11-018 Full Text: PD
Evaluating the Importance of Ecosystem Services in University Campus
No full textUniversity campuses provide a variety of ecosystem services (ES) that play an important role in both physical and mental benefits for students. However, the importance and actual service performance of ES in universities were not clearly perceived in Vietnam. This study was conducted to fill these gaps with the objectives of (1) assessing students' perceptions of the importance of ecosystem services on their university campus and (2) assessing students' satisfaction with these ecosystem services. Using the interview method, the study collected research data from 210 students at Can Tho University (CTU), a large university in Vietnam. The results of the study have confirmed the importance of ecosystem services such as trees, lawns, water bodies, and buildings on CTU's campus. With modern design, buildings play an important role in creating space to organize formal classes, self-study, and group work for students. Green spaces not only improve air temperature and bring high aesthetic value, but they are also habitats for many species of animals and plants. Most students were very satisfied with the ES provided by the CTU's campus. However, the functions of the grass and water bodies ecosystem need to be improved, as the student satisfaction with these ES was significantly lower than the value they expected. The results of analyzing the importance and satisfaction of ES will be a useful basis for making decisions on planning and developing ecosystems. This is a new research direction in Vietnam that needs continued research and application. Doi: 10.28991/CEJ-2024-010-01-015 Full Text: PD
Concrete Strength and Aggregate Properties: In-Depth Analysis of Four Sources
No full textIn the field of Reinforced Concrete Construction, concrete emerges as the predominant and extensively employed construction material. Concrete comprises a solid, chemically inert granular substance called coarse aggregate (CA) bonded with cement and water. Compared to fine aggregate or cement, CA has a larger volume of concrete. By examining the characteristics of the coarse aggregate using various laboratory testing processes, the coarse aggregate may be properly used in concrete. Bangladesh is experiencing significant growth in its infrastructure industry due to the construction of mega projects nationwide. For the building of RCC in Bangladesh, coarse aggregate is mainly procured from two sources in Bangladesh, and another is imported from China. This study aims to develop a clear understanding of aggregate and concrete strength quality for different coarse aggregates and track changes in the appearance of CA from multiple sources in China and Bangladesh. Coarse aggregates were collected from four prominent sources: Jaflong and Bholaganj (Bangladesh), Shandong, and Jiangsu (China). ACV (aggregate crushing value), gradation, voids, and unit weight; AIV (aggregate impact value), absorption, specific gravity, and resistance to abrasion-induced deterioration; and Los Angeles (LA) machines' impact tests have been conducted for all sources of CA. The concrete cylinder was made and tested for all sources of CA with the same ratio of cement, sand, and water to know the concrete strength for different CAs. Doi: 10.28991/CEJ-2024-010-04-016 Full Text: PD
Estimation of the Physical Progress of Work Using UAV and BIM in Construction Projects
No full textThe delay in the physical progress of construction creates additional costs, missed deadlines, and quality issues. The research aimed to estimate the physical progress of the project by using unmanned aerial vehicles (UAVs) and building information modeling (BIM). The methodology comprised capturing 848 high-resolution images of the Civil Engineering Laboratory construction site at the National University of Jaen, Cajamarca, Peru, using the Phantom 4 RTK drone. The photographs were processed using Agisoft 2.0.1 software, resulting in a point cloud. This was then imported into ReCap Pro 2023 software, which was used to assess the quality of the points. The Revit 2023 software was subsequently utilized to establish the phase parameters, linking the BIM model with the point cloud, filtering the model, and eventually exporting it to the Power BI 2023 software. The work's estimated progress utilizing the proposed methodology was 42.82%, which was not statistically significant compared to the Public Works Information System (INFOBRAS) of 43.14%. This allows for the automation of customary processes, the identification of crucial issues, and prompt decision-making. The study's originality lies in the suggestion of integrating aerial imagery with drones and BIM modeling for the real-time and precise estimation of work progression. This method provides a precise and effective substitute for traditional techniques for gauging the tangible advancement of projects. Doi: 10.28991/CEJ-2024-010-02-02 Full Text: PD
Effects of Varied Soil Leveling Methods on Physical Properties: A Comparative Analysis
No full textThe total cultivated land area in this context is 8,664,000 square meters, which constitutes about 4% of Egypt's territory. The cultivation relies on old land dams, lines, and furrow surface irrigation systems. A significant portion (76%) of the cultivated land is irrigated with high-density leveled soil instead of unlevelled soil. Leveled soil has very low clay and organic matter content. Land leveling is a preparation or modification process that provides a suitable surface for seeding production. It involves reducing high areas and raising low or deep spots to create a more even surface. Laser-controlled land leveling is a technique that helps create a more even surface by reducing high areas and raising low spots. This process aims to eliminate surface irregularities and create a level plane, which can significantly impact crop germination, uniformity, and, ultimately, the yield of field crops. Laser technology allows for precision in land leveling, ensuring a more consistent seed depth, better water distribution, and improved crop-growing conditions. By creating a more uniform surface, the potential for more consistent crop growth, better water retention, and improved distribution of nutrients is increased. The study's main objective appears to be to determine the most appropriate types of land leveling that can be implemented and to analyze how land leveling treatments affect the physical properties of the soil during different seasons. The data shows that the leaser treatment decreased soil porosity in both seasons, dropping values from 57.36% to 54.34% in the first season and from 55.47% to 51.32% in the second season. In contrast, the "rotary treatment" had the opposite effect, increasing soil porosity in both seasons. The values rose from 57.34% to 59.62% in the first season and from 57.74% to 59.25% in the second. Observing how these treatments had different impacts on the soil over time is intriguing. Doi: 10.28991/CEJ-2024-010-11-014 Full Text: PD