jcer_1786867566 20260816080606000 CMV Verlag khoffman@cmv-verlag.com In collaboration with Golestan University and Assoc. Prof. Dr. Morteza Jamshidi Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 09 01 2025 7 3 Seyed Abbas Hosseini Associate professor, Faculty of Engineering, Yasouj University, Yasouj, Iran. Mansour Bagheri Associate professor, Faculty of Mining, Civil and Chemical Engineering, Brijand University of Technology, Birjand, Iran Heavyweight concrete incorporating iron aggregates is widely utilized as a radiation-shielding material in environments with harmful radiation due to its high density. Although this material is also employed as a structural component, certain mechanical properties, such as the bond strength between concrete and reinforcing steel bars, remain insufficiently studied. This paper investigates the bond strength of concrete containing varying percentages of iron pellets and its interaction with steel reinforcement. For this study, 25%, 75%, and 100% of the concrete aggregate was replaced with iron pellets, ensuring an appropriate grain size distribution. After curing under standard conditions, the specimens were subjected to direct pull-out tests. The results indicate that, except for the sample with 25% iron pellets, the inclusion of iron pellets slightly reduces compressive strength but enhances bond strength across all samples. Notably, adding 25% iron pellets combined with 5% micro silica in heavyweight concrete significantly improves compressive strength by 20% and bond strength by 43%. 09 01 2025 69 75 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.7.3.69 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/168 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/168/206 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/168/206 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 09 01 2025 7 3 Hossein Alimohammadi Terracon Consultants, Inc., Nashville, TN, USA 37217 David Been Terracon Consultants, Inc., Nashville, TN, USA 37217 James Duncan Terracon Consultants, Inc., Nashville, TN, USA 37217 This study presents a forensic investigation into pavement distress in a concrete apron located in Nashville, Tennessee. The investigation involved detailed engineering observations and a comprehensive pavement condition survey in accordance with ASTM D5340. To identify the underlying causes of deterioration, petrographic examinations were conducted on three concrete cores extracted from the apron, following ASTM C856 guidelines. The analysis revealed consistent aggregate distribution, primarily composed of micritic limestone and quartz-based sand, with air content (total of entrapped and purposefully entrained air) ranging from 3.9% to 5.2% and air void spacing factors exceeding American Concrete Institute (ACI) recommendations for freeze-thaw durability. No carbonation was detected in the cores, but moderate to abundant ettringite, calcium hydroxide, and alkali-silica gel resulting from Alkali-Silica Gel (ASG) were observed lining voids and fractures. The findings indicate that Alkali-Silica Reaction (ASR)-related damage, exacerbated by cyclic wetting and drying, is a primary contributor to the pavement deterioration. Freeze-thaw damage due to inadequate air entrainment was also identified as a contributing factor. Based on the results, recommendations for improving the long-term performance and durability of the concrete apron include using low-alkali cement, selecting better-graded and less reactive aggregates, increasing the percentage of purposefully entrained air to reduce air void spacing and improve freeze-thaw durability, and incorporating supplementary cementitious materials (SCMs) to reduce alkali availability and enhance ASR resistance. We note the use of lithium nitrate has also been proven to mitigate ASR in new concrete. However, the mechanism of mitigation is not fully understood, and the relatively high cost and limited availability of lithium introduces challenges for this alternative.  This study underscores the importance of petrographic examination in understanding concrete deterioration mechanisms and developing targeted repair strategies to enhance infrastructure durability. 09 01 2025 40 51 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.7.3.40 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/170 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/170/208 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/170/208 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 09 01 2025 7 3 Morteza Iraniparast Faculty of Civil Engineering, Semnan University, Semnan, Iran; M. Iman Khodakarami Faculty of Civil Engineering, Semnan University, Semnan, Iran; Understanding the dynamic behavior of soil layers under seismic loading is pivotal for accurate seismic design and risk assessment. This study conducts a two-dimensional equivalent linear site response analysis using the Scaled Boundary Finite Element Method with Rayleigh damping to enhanced modeling accuracy. SBFEM combines the advantages of finite and boundary element methods, offering high efficiency in simulating wave propagation and stress concentrations in semi-infinite domains. A MATLAB implementation of the method was validated against previous studies, confirming consistent accuracy across various soil profiles and seismic scenarios. The method demonstrates convergence, accuracy, and stability, requiring fewer elements due to boundary-only discretization. This reduces both computational cost and time while accurately modeling the infinite domain condition. The findings highlight the method’s effectiveness for site response analysis under diverse seismic inputs and layered soil configurations, combining the equivalent linear method with SBFEM as a robust and practical tool for dynamic geotechnical applications.                             09 01 2025 52 68 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.7.3.52 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/174 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/174/207 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/174/207 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 09 01 2025 7 3 Selman KAHRAMAN Karabük University https://ror.org/04wy7gp54 İnan KESKİN Karabük University https://ror.org/04wy7gp54 Taner Gürbüz Karabük University https://ror.org/04wy7gp54 This study evaluates slope stabilization methods using gravity stone walls, reinforced concrete cantilever walls, and pile shoring systems. Stability and economic performance of these systems were compared through analyses conducted with Plaxis 2D and İstCAD software on a model slope subjected to increasing excavation depths. Results show that gravity stone walls are more economical up to 5 m, while cantilever walls are preferable between 5–9 m. Beyond 9 m, both methods become inadequate, and pile shoring systems provide the most effective solution. Each method's advantages and limitations were assessed based on field applicability, cost, and stability. 09 01 2025 15 28 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.7.3.15 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/173 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/173/209 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/173/209 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 09 01 2025 7 3 Wissam Hamad Babol Noshirvani University of Technology https://ror.org/02zc85170 Mehdi Dehestani Babol Noshirvani University of Technology https://ror.org/02zc85170 There is no specific model to predict the flexural capacity of ultra-high-performance concrete (UHPC) beams with a low reinforcement ratio. Accordingly, a comprehensive experimental database containing 162 datasets was gathered from literature to propose an explicit analytical model containing various critical features, including fiber volume fraction, fiber aspect ratio, fiber strength, water-to-binder () ratio of mixture, and reinforcement ratio. Additionally, a supplementary experimental study involving a large-scale UHPC beam with a very low reinforcement ratio (almost negligible) was conducted to verify the model's performance. The findings revealed that the proposed bending model achieved an IAE of 10.8% and a COV of 1.04, indicating its high accuracy in comparison to a comprehensive experimental dataset comprising 162 large-scale beam tests. Furthermore, the comparison between the experimental results of the tested beam and the proposed model showed a deviation of 4.5%, which supports the effectiveness of the flexural capacity formulation. A parametric statistical analysis was conducted using Minitab software to evaluate the influence of key parameters affecting the roles of fiber and matrix. 09 01 2025 1 14 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.7.3.1 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/181 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/181/211 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/181/211 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 09 01 2025 7 3 The Effect of Employing a Thermal Insulation Layer in the Building Façade on Energy Consumption Amir Sina Darabi Department of Civil Engineering˓ Science and Research Branch˓ Islamic Azad university˓ Tehran˓ Iran Mehdi Ravanshadnia Department of Civil Engineering˓ Science and Research Branch˓ Islamic Azad university˓ Tehran˓ Iran Although currently, a large part of the existing buildings are considered inefficient in terms of energy, the ability to save energy consumption up to 80% has been proven in residential and commercial buildings. This study aims to calculate energy consumption during the operational phase caused by various scenarios of thermal insulation combinations in a building's exterior shell. The simulation was conducted using Design Builder software, with a five-story residential building in Tehran as the case study. Initially, the building was modeled in Design Builder, and keeping all other characteristics constant, ten scenarios were defined: nine using different types of thermal insulation and one without insulation. The software outputs for each scenario were analyzed. Results showed that the best thermal insulation layer is polyurethane foam, which saves 1070.15 kilowatt-hours of energy during one year of the building's operation. This article can help designers and construction engineers optimize the energy consumption of buildings by deciding the right materials.  © 2017 Journals-Researchers. All rights reserved 09 01 2025 29 39 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.7.3.29 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/171 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/171/210 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/171/210 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 09 01 2025 7 3 Hosein Sarkoyeh Department of Civil Engineering,Cha.C.,Islamic Azad univerity, Chalus, Iran Mohammad Ali Hajarizadeh Department of Civil Engineering, Bu.C.,Islamic Azad univerity, Bushehr, Iran Saeed Alaie Department of Civil Engineering, Ah.C.,Islamic Azad univerity, Ahvaz, Iran Base isolation solutions are efficient alternatives for seismic protection of buildings and for enhancing resilient capacity. Currently, seismic isolation is focused principally on the critical infrastructure of public health, transportation, education, etc. The seismic response of multi storied base-isolated structure to various types of isolation systems connected using viscoelastic dampers to the adjacent dissimilar base isolated or fixed base structure is investigated. The multi- storied structures are modelled as a shear type structure with lateral degree of freedom at each floor, which are connected at different floor levels by viscoelastic dampers. The variation of top floor absolute acceleration of both the buildings and bearing displacement under different real earthquake ground motions is computed to study the behavior and effectiveness of resulting connected system. It is concluded that connecting the two adjacent base isolated buildings with the viscoelastic dampers is useful in controlling large hearing displacements in the base isolated structures thereby eliminating the isolator damages arising due to instar billet at these large displacements or pounding with adjacent ground structures during earthquakes. The viscoelastic damper connection between adjacent structures is found to be most effective when the adjacent base-isolated and fixed base buildings are competed. Such scheme is hence useful in upgrading the seismic performance of existing fixed base structures adjacent to a base isolated structure. 09 01 2025 76 86 https://creativecommons.org/licenses/by/4.0 10.61186/JCER.7.3.76 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/158 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/158/205 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/158/205