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Research Article
Influence of Steel Fiber on Compressive Strength and Crack Pattern of Recycled Aggregate Concrete
Issue:
Volume 13, Issue 2, April 2025
Pages:
61-67
Received:
2 March 2025
Accepted:
12 March 2025
Published:
31 March 2025
Abstract: The use of recycled aggregates rather than new aggregates is suggested by the depletion of natural resources and demolition trash. Compared to natural aggregate, recycled aggregate gives concrete less strength. Concrete can be strengthened by adding fiber, such as steel fibers, at a low volumetric proportion. This study aims to determine the concrete's compressive strength by adding steel fiber (30 mm in length) to volume fractions of 0.45%, 0.9%, 1.35%, and 1.80% of the concrete. Coarse aggregates specially recycled stone was obtained from demolished concrete structures and laboratory waste and used after proper treatment. Based on the mix design, a concrete strength of 30 MPa and a water to cement ratio of 0.46 were selected. This type of concrete was anticipated to be utilized for RCC beams. To make sure the designed concrete was workable, the slump test was conducted. The slump showed decreasing value when steel fiber was added accordingly. After seven and twenty-eight days, the concrete cubes' compressive strength was finally measured. With steel fiber utilized at the ideal proportion of 1.35% of the volume of concrete, the results demonstrated that the concrete achieved the required strength and slightly improved in compressive strength. In conclusion, steel fiber combined with recycled stone in the right proportion could be a sustainable substitute for RCC structures.
Abstract: The use of recycled aggregates rather than new aggregates is suggested by the depletion of natural resources and demolition trash. Compared to natural aggregate, recycled aggregate gives concrete less strength. Concrete can be strengthened by adding fiber, such as steel fibers, at a low volumetric proportion. This study aims to determine the concre...
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Research Article
Effects of Masonry Infills on the Lateral Stiffness of Reinforced Concrete Buildings
Daniel Dibaba Awayo*
,
Yohannes Gudeta Deressa
Issue:
Volume 13, Issue 2, April 2025
Pages:
68-80
Received:
2 March 2025
Accepted:
18 March 2025
Published:
31 March 2025
Abstract: Block infills are usually regarded as non-loadbearing components in buildings, and are frequently neglected in the analysis and design of building structures. The main objective of this study is to perform static nonlinear analysis of hollow concrete block (HCB) infilled reinforced concrete buildings (RC) subjected to a seismic excitation. For this study, three different buildings were selected as case studies: a seven-story, an eleven-story, and a sixteen-story building, each with a standard floor plan. Bare RC frame buildings were analyzed and designed on ETABS based on Ethiopian Buildings Code Standards (ES EN: 2015). While numerical modeling and static pushover analysis of the designed building model cases were computed using SeismoStruct. The masonry panel model was employed to reproduce the behaviour of the full-scale infilled frame model using diagonal compression struts. The results from the pushover analysis were used to determine the fundamental vibration period and generate the capacity curves. It was observed that the presence of infills had a highly significant impact, causing a considerable increase in base shear until the infills began to crack. Additionally, the infills played a major role in reducing the fundamental vibration period of the structures. A seismic base shear of 5,150kN was found at significant damage performance levels with the corresponding roof displacements of 300, 420, and 600mm for seven-story, eleven-story and sixteen-story building models respectively. While their respective on set cracks of infills were observed at 17mm, 20mm and 24mm roof displacement. Therefore, for relatively high-rise buildings, the contribution of infills in terms of stiffness and energy dissipation becomes more important, as their impact on base shear and fundamental period is both substantial and significant.
Abstract: Block infills are usually regarded as non-loadbearing components in buildings, and are frequently neglected in the analysis and design of building structures. The main objective of this study is to perform static nonlinear analysis of hollow concrete block (HCB) infilled reinforced concrete buildings (RC) subjected to a seismic excitation. For this...
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Review Article
Advances in Seismic Design for High-Rise Buildings: A Systematic Review of New Techniques and Materials
Girmay Mengesha Aznaw*
Issue:
Volume 13, Issue 2, April 2025
Pages:
81-95
Received:
15 November 2024
Accepted:
2 January 2025
Published:
22 April 2025
DOI:
10.11648/j.ajce.20251302.13
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Abstract: The intricate seismic design concerning skyscrapers in urban area is one of the global problems especially as people population is shifting towards areas that are precisive prone. This systematic literature review seeks to establish the current changes that have occurred in construction high-rise buildings by focusing on the design methodologies and materials the thesis presents an overview of progress in the development of construction materials and elements regarding seismic impacts on structures. Materials that are talked about include bar reinforcing steel, shape memory alloys, and composite materials. The case studies emphasize that the aforementioned technologies do operate and provide various advantages to their users while some implementation problems do exist. Noting that design of seismic means such as cross bracing, rough bracing, seismic shear walls so meshes are important in the overall design layout. This review also delineates key concepts related to the future orientation of seismic buildings design that include new developing building technological trends. By synthesizing current advancements and identifying research gaps, this review serves as a valuable resource for researchers, engineers, and policymakers dedicated to advancing the seismic resilience of high-rise buildings. It underscores the need for continued innovation and interdisciplinary collaboration to ensure the safety and sustainability of urban infrastructure in seismic regions.
Abstract: The intricate seismic design concerning skyscrapers in urban area is one of the global problems especially as people population is shifting towards areas that are precisive prone. This systematic literature review seeks to establish the current changes that have occurred in construction high-rise buildings by focusing on the design methodologies an...
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Research Article
Analysis of National Infrastructure Integration in Ethiopia: Current State and Recommended Solutions
Michael Menberu*
Issue:
Volume 13, Issue 2, April 2025
Pages:
96-104
Received:
17 March 2025
Accepted:
1 April 2025
Published:
29 April 2025
DOI:
10.11648/j.ajce.20251302.14
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Views:
Abstract: The study provides a comprehensive examination of the challenges and opportunities within Ethiopia's infrastructure sector. As the country continues to grow economically and experience rapid urbanization, the demand for efficient and well-integrated infrastructure systems has become increasingly critical. The analysis focuses on evaluating the current state of national infrastructure integration, identifying key challenges, and proposing actionable solutions to improve the planning, execution, and management of infrastructure projects across the country. The assessment reveals that Ethiopia's infrastructure sector is characterized by fragmented integration among key stakeholders, including ERA, EEU, EEP, Ethio Telecom, EAG, and IPDC, as well as various private sector contractors and service providers. This lack of cohesive collaboration has led to inefficiencies, project delays, and cost overruns, significantly affecting the overall effectiveness of infrastructure projects. Important issues identified include inefficiencies in integration mechanisms, fragmented communication and collaboration among stakeholders, bureaucratic hurdles that delay project approvals and execution, inadequate resource allocation, poor communication practices, limited stakeholder engagement, and capacity constraints that undermine the successful completion of infrastructure projects. To address these challenges, the study proposes several solutions aimed at improving national infrastructure integration. These include enforce the revised compensation proclamation at the local level, developing a comprehensive integrated infrastructure master plan, establish integrated planning and integration platforms, strengthen communication protocols, improve resource management, and invest in capacity building through training and development programs.
Abstract: The study provides a comprehensive examination of the challenges and opportunities within Ethiopia's infrastructure sector. As the country continues to grow economically and experience rapid urbanization, the demand for efficient and well-integrated infrastructure systems has become increasingly critical. The analysis focuses on evaluating the curr...
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Research Article
Mechanical Performances of Pretreated Porous Convenient Asphalt Concrete
Cheng Tsung Lu,
Ming Yan Chung*
Issue:
Volume 13, Issue 2, April 2025
Pages:
105-115
Received:
17 March 2025
Accepted:
24 April 2025
Published:
29 April 2025
DOI:
10.11648/j.ajce.20251302.15
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Views:
Abstract: Convenient Asphalt Concrete (CAC) is a kind of Asphalt Concrete with new technology, in which a pre-treated emulsified Asphalt is prepared firstly to avoid demulsification during mixing and then mixed directly and steadily with cement and aggregate. In this technology, cement and pre-treated emulsified Asphalt are evenly mixed into a binder, namely Convenient Asphalt Mastic (CAM). CAM is a new type of binder for modified asphalt concrete, with low energy consumption, less pollution, and normal atmospheric temperature construction. The mixture, named Porous Convenient Asphalt Concrete (PCAC), is formed by mixing CAM as a binder and aggregate with gradation adjustment according to the ‘Permeable Pavement Guide’ of the Japan Road Contractors Association. In this study, the mechanical properties of PCAC and Hot Mix Porous Asphalt Concrete (PA) are compared and analyzed under the control of wrap film thickness and porosity. The experimental results show that at the same porosity and under the most appropriate film thickness of PCAC and PA, the Marshall Stability Value and the Tensile Strength of PCAC is 3 to 4 times stronger than PA all. There is positive correlation with first, the strength of the binder wrapped around aggregate granule, and second, the aggregate particles being bonded well with each other. It is because that CAM has higher consistency, it can form thicker wrap film around the aggregate without adding any staple fiber, and CAM has higher strength after hardening. Therefore, the overall mechanical performances of PCAC are much better than PA. Consequently, PCAC can bear a larger axle load than PA. That reduces the damage of axle pressure on porous asphalt pavement and prolongs the service life of porous asphalt pavement.
Abstract: Convenient Asphalt Concrete (CAC) is a kind of Asphalt Concrete with new technology, in which a pre-treated emulsified Asphalt is prepared firstly to avoid demulsification during mixing and then mixed directly and steadily with cement and aggregate. In this technology, cement and pre-treated emulsified Asphalt are evenly mixed into a binder, namely...
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