jcer_1787037855 20260818072415000 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 03 01 2026 8 1 Fatiha Iguetoulene Mouloud Mammeri University of Tizi-Ouzou https://ror.org/050ktqq97 Youcef Bouafia Mouloud Mammeri University of Tizi-Ouzou https://ror.org/050ktqq97 Mohand Said Kachi Mouloud Mammeri University of Tizi-Ouzou https://ror.org/050ktqq97 This paper studies the structural behavior of prestressed concrete beams and steel fiber reinforced concrete piles. A nonlinear finite element formulation based on the principle of virtual work is developed to analyze the response of these prestressed structural elements under applied loads. The model accounts for material nonlinearity, second-order effects, and variable stiffness through an incremental loading procedure. Simpson’s integration scheme is adopted to evaluate the cross-sectional response of each element. The governing equations describing beam behavior are established, and the influence of compressive strength and prestressing force on structural performance is examined. Experimental tests conducted on prestressed concrete beams and steel fiber–reinforced concrete piles are used to validate the proposed approach. A comparison between numerical and experimental results demonstrates the accuracy and reliability of the developed formulation. 03 01 2026 https://creativecommons.org/licenses/by/4.0 10.66224/JCER.8.1.1 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/219 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/219/234 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/219/234 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 03 01 2026 8 1 Navid Jamali Islamic Azad University of Chalous https://ror.org/02cytaa95 Rahamt Madandoust University of Guilan https://ror.org/01bdr6121 In reinforced concrete structures that are in corrosive environmental conditions, there is always a discussion of reinforcement corrosion. Therefore, because of the smaller diameter compared to longitudinal rebars and closer to the surface and consequently closer to the corrosive factors, stirrups are more affected by this corrosion. One of the most effective ways to prevent corrosion of stirrups is to use FRP rebars in structures exposed to corrosion. One of the disadvantages of using FRP rebar is that it is brittle, which makes it impossible to bend these rebars in a workshop environment. Therefore, a group of researchers suggested the use of straps made of FRP plates as stirrups and concluded some laboratory studies in this field. Now, the main goal of this study is to numerically investigate the behavior of beams made with this type of stirrups. For this purpose, 13 beams were modeled in Abaqus software and subjected to three-point bending loading. Also, things such as the type of FRP used, the width of the stirrups, the number of layers of the stirrups and the installation location of these stirrups were investigated and studied. The results of this study showed FRP stirrups with a cross-section equal to steel stirrups have a higher load capacity than beams with steel stirrups. Also, in terms of the beam's ductility, the beam with FRP stirrups has less ductility than the beam with steel stirrups. Regarding the effect of the number of FRP stirrup layers, the results showed that in stirrups with fixed width and variable number of layers, increasing the number of FRP stirrup layers will increase the bearing capacity and reduce ductility. 03 01 2026 https://creativecommons.org/licenses/by/4.0 10.66224/JCER.8.1.9 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/167 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/167/235 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/167/235 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 03 01 2026 8 1 Meysam Gholami University of Guilan https://ror.org/01bdr6121 Omid Hasanshahi University of Minho https://ror.org/037wpkx04 This review article provides a comprehensive investigation into the effects of utilizing fly ash (FA) along with other mineral additives such as metakaolin (MK), silica fume (SF), hydrated lime (HL), and others on the properties of Self-Compacting Concrete (SCC). The primary objective of this study is to analyze and synthesize existing research on the simultaneous influence of various chemical additives and fly ash on the microstructure and compressive strength of self-compacting concrete. Recognized for its ease of implementation and enhanced performance, self-compacting concrete is considered an advanced technology in the concrete industry, and the use of mineral additives, particularly fly ash, can contribute to the improvement of its mechanical properties and durability.The methodology of these studies primarily involves examining the concrete microstructure using Scanning Electron Microscopy (SEM) and evaluating the compressive strength of concrete specimens at different ages. Results indicate that partial replacement of cement with activated fly ash (using sodium hydroxide) can reduce the hydration process while enhancing pozzolanic reactions, leading to improved strength properties. The optimal performance of activated fly ash-based SCC, in terms of strength, was observed at 10% to 15% replacement. SEM images revealed that fly ash particles are spherical, whereas activated fly ash particles are angular and elongated, which contributes to improved concrete matrix density and reduced porosity, thereby increasing compressive strength.Furthermore, studies on concrete containing mineral additives demonstrated that MK provides higher initial strength compared to other additives. This study concludes that the use of fly ash and other mineral additives, particularly in combination with activators or hydrated lime, can effectively enhance the mechanical and microstructural properties of self-compacting concrete, making it a sustainable and efficient option for construction applications. This review also underscores the importance of a profound understanding of the relationship between material composition, microstructure, and mechanical properties for the optimal formulation of SCC. 03 01 2026 https://creativecommons.org/licenses/by/4.0 10.66224/JCER.8.1.16 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/210 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/210/236 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/210/236 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 03 01 2026 8 1 Zahra Heidari Hakim Sabzevari University https://ror.org/00zyh6d22 Rasoul Shadnia Hakim Sabzevari University https://ror.org/00zyh6d22 Davood Mostofinejad Isfahan University of Technology https://ror.org/00af3sa43 This research investigates the possibility of producing green concrete using Carbonation Lime Residue (CLR), a waste by-product from the Naghsh-e Jahan Sugar Factory in Isfahan (Iran). The primary objective is to recycle this industrial waste by utilizing it as a partial replacement for cement in concrete production, aligning with waste management goals, environmental preservation, and economic benefits. Concrete samples were prepared with different percentages of CLR replacement (0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, and 40%) for cement, maintaining a constant water-to-cement ratio of 0.35. These samples were subjected to compressive strength tests (at 7, 28, and 56 days) and tensile strength tests (Brazilian method). The results indicated that both compressive and tensile strengths decrease with an increase in the replacement percentage. This reduction is primarily attributed to the presence of impurities and sugary substances in the CLR, as confirmed by SEM and EDX analyses. However, it was observed that up to a 25% replacement level, the reduction in compressive and tensile strengths was less than respectively 15% and 10%. This level of reduction is considered acceptable given the environmental and economic advantages derived from utilizing this waste material. Therefore, using waste CLR as a cement replacement in concrete up to 25% is deemed a practical and effective solution, particularly for non-structural applications or in regions near sugar factories, contributing to sustainable development and a circular economy. 03 01 2026 https://creativecommons.org/licenses/by/4.0 10.66224/JCER.8.1.39 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/211 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/211/227 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/211/227 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 03 01 2026 8 1 Amin Moradi Amirkabir University of Technology https://ror.org/04gzbav43 Mohsen Asgharinia Amirkabir University of Technology https://ror.org/04gzbav43 Project delay remains one of the most persistent challenges in construction management, often leading to significant cost overruns, contractual disputes, and stakeholder dissatisfaction. Traditional scheduling and delay analysis methods—such as Critical Path Method (CPM), Earned Value Management (EVM), and conventional Extension of Time (EOT) techniques—tend to overlook the relative importance of activities and the dynamic nature of project execution. This study introduces the Weighted Delay Index (WDI), a novel metric that integrates activity-specific weights with dynamic critical path analysis to provide a more nuanced evaluation of delay severity. Activity weights are derived through the Analytical Hierarchy Process (AHP), incorporating four key dimensions: time, cost, risk, and technical impact. The methodology is validated through multiple case studies of construction projects, where WDI trends are compared against actual project delays determined via Time Impact Analysis. Results indicate that Project Duration is the dominant predictor of overall delays, while WDI offers significant diagnostic and managerial value by identifying critical activities whose delays disproportionately affect project performance. Workforce Intensity is found to moderate delay outcomes, with higher intensity generally reducing delay severity. The proposed framework provides project managers with an early-warning and prioritization tool, enabling targeted intervention strategies that go beyond aggregated delay measures. The study contributes to both theory and practice by bridging the gap between deterministic scheduling and dynamic, activity-sensitive delay analysis. 03 01 2026 https://creativecommons.org/licenses/by/4.0 10.66224/JCER.8.1.47 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/201 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/201/233 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/201/233 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 03 01 2026 8 1 Hadi Bahri Rahman Institute of Higher Education https://ror.org/01k1m6p08 In this study, the performance and efficiency have been investigated of friction damper in semi-active control mode in structural responses under the influence of Chichi, Kobe, Tabas and Gazli earthquakes in the near field. Semi-active friction dampers made up of two plates that are slipping over. The contact force between the pages is changed according to the order of the control algorithm and the force on the structure is adjusted at any time during the earthquake. The LQR control algorithm and the shear control rule have been used to determine the contact force at any given moment. A structural ten-story steel X shape bracing system in both directions under dynamic analysis for numerical studies selected and subjected to vibration 4 earthquake specifications and content of different frequency in software Etabs to obtain matrices of mass and stiffness and Matlab to evaluate the different states of being The damper has been investigated. Structural responses in all classes is determined and compared. The results indicate that the use of a friction damper leads to a reduction of displacement, In the mode of using the damper in a semi-active control mode, it is better than active or inactive mode. The damper layout is also examined in four modes, which shows that the use of the damper around the structural plan is better. For example, the base shear when the damper is in around the plan, In active and inactive control mode, it has increased by 41.4% and 84.86% relative to the semi-active control status 03 01 2026 https://creativecommons.org/licenses/by/4.0 10.66224/JCER.8.1.61 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/161 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/161/232 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/161/232 Journal of Civil Engineering Researchers jcer 2538-516X 2538-516X 03 01 2026 8 1 Mohammad Javad Zeynali University of Torbat Heydarieh https://ror.org/03ncps145 Mohammad Nazeri Tahroudi Lorestan University https://ror.org/051bats05 Omolbani Mohammadrezapour Gorgan University of Agricultural Sciences and Natural Resources https://ror.org/01w6vdf77 In groundwater flow modeling, as in any modeling problem, a certain amount of error is inevitable. In groundwater flow and contaminant transport modeling, recharge and discharge wells act as point sources or sinks. How these wells are treated can influence accuracy and reduce uncertainty or increase the amount of error. This study investigates an intelligent aquifer mesh. To illastrate the theory, two hypothetical aquifers with triangular and square elements were examined, in both confined and unconfined conditions. In the intelligent aquifer mesh, after gridding the model domain, pumping or recharge wells are considered as nodes. Consequently, the numbering of nodes and elements are updated accordingly. Groundwater flow modeling is performed on the updated mesh to enhance accuracy. The results of this research indicated that considering the recharge and pumping wells as a node and re-gridding the model area can perform groundwater flow modeling with more accuracy and ultimately the results will be more reliable. 03 01 2026 https://creativecommons.org/licenses/by/4.0 10.66224/JCER.8.1.77 https://www.journals-researchers.com/ojs/index.php/jcer/article/view/221 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/221/238 https://www.journals-researchers.com/ojs/index.php/jcer/article/download/221/238