https://civiljournal.semnan.ac.ir/ Journal of Rehabilitation in Civil Engineering en daily 1 Tue, 28 Apr 2026 00:00:00 +0330 Tue, 28 Apr 2026 00:00:00 +0330 https://civiljournal.semnan.ac.ir/article_10595.html Field observations at a state building project in Kermanshah, Iran, revealed significant deformation and cracking in the basement retaining walls. Investigation showed that, although the walls were originally designed to act integrally with the main structural frame, construction deviations led to their separation from the building system, causing them to behave as independent cantilever elements under soil pressure. Structural assessment was first performed using ETABS to evaluate bending moments, shear forces, and wall–frame interaction under static and pseudo-static seismic soil loading. The results indicated that the existing wall configuration failed to meet flexural and shear capacity requirements, with base moments exceeding the calculated section capacity of 95 kN.m per meter width. Two rehabilitation strategies were examined: (i) increasing wall thickness, and (ii) re-establishing structural continuity by connecting the retaining walls to the main structural frame through reinforced concrete jacketing and diaphragm anchorage. The second approach was selected for implementation. To validate the proposed solution, soil–structure interaction and global stability were analyzed using PLAXIS2D. The factor of safety increased from 1.085 in the existing condition to 1.565 after rehabilitation, and wall displacement was significantly reduced. The integrated system demonstrated improved load redistribution and structural coherence under both static and seismic conditions. The study highlights the importance of structural continuity and soil–structure interaction in the assessment and rehabilitation of retaining walls in seismic regions. https://civiljournal.semnan.ac.ir/article_10283.html Pavement distress detection is a critical task for ensuring road safety and maintaining transportation infrastructure, particularly in environments with limited resources. This study conducts a comprehensive evaluation of ten YOLO object detection modelscomprising five YOLOv5 and five YOLOv8 variants (n, s, m, l, x) for identifying seven pavement defect classes using 500 high-resolution UAV images. The dataset, manually annotated and split into 70% training and 30% validation sets, was used to train all models under uniform hyperparameter settings. The performance was assessed using standard metrics: mAP@0.5:0.95, mAP@0.5, Recall, Precision and F1-score. Results showed that YOLOv8 consistently outperformed YOLOv5 across all dataset sizes, with YOLOv8l reaching the highest mAP@0.5:0.95 of 0.381, and YOLOv8m providing the best balance between accuracy (0.344), training time (67 minutes), and robustness. Statistical validation using Two-Way ANOVA confirmed significant performance differences (F = 13.81, p = 0.0006, Cohen’s d = 0.73). Further analysis using Repeated Measures ANOVA and Bonferroni-corrected t-tests reinforced YOLOv8l's superiority over other variants. Despite the limited dataset size the findings demonstrate YOLOv8’s effectiveness and reliability in low-resource conditions without the need for image augmentation or preprocessing. The main innovation lies in providing a statistically validated benchmark for UAV-based pavement monitoring under small dataset conditions, highlighting YOLOv8’s superior efficiency and generalization without augmentation or preprocessing. This study provides a reproducible benchmark for real-time UAV-based pavement distress detection, offering insights for deploying lightweight deep learning systems in resource-constrained settings. https://civiljournal.semnan.ac.ir/article_10311.html Rapid urban development has significantly increased construction waste, contributing to the depletion of natural resources and environmental degradation. As a result, the use of recycled aggregates has gained global attention as a sustainable alternative in construction materials. In the current study, experimental tests were performed on 72 samples where the coarse normal aggregate was replaced by 0%, 25% and 50% by volume with coarse recycled aggregate. Furthermore, the test samples comprised four types of specimens with Polypropylene fibers (PP) and steel fibers, including with no fibers, with 0.4% PP and 0% steel fibers, with 0.4% PP and 0.5% steel fibers, and with 0.4% PP and 1.0% steel fibers, wherein all ratios are volumetric. This study investigated the energy absorption and ductility of notched recycled concrete beams reinforced with hybrid combinations of polypropylene and steel fibers under three-point bending tests. The results were validated using analysis of variance (ANOVA). Findings demonstrated that polypropylene fibers contributed to homogenizing stress distribution by delaying micro-crack initiation, while steel fibers enhanced pull-out resistance and bridged macro-cracks, synergistically improving the energy absorption capacity. However, increasing the recycled aggregate content generally led to a reduction in fracture energy, attributed to the weaker residual cement paste and damage induced during aggregate processing. https://civiljournal.semnan.ac.ir/article_10321.html This study presents a graphical solution for determining the ‎initial positioning of Conventional Outrigger (CO) system in ‎the shear core with discontinuity in moment of inertia, using ‎the energy method in tall building. In this model a cantilevered ‎beam presents The framed-tube system, while the CO system ‎is modeled by rotational springs located at their respective ‎positions. By applying the energy method, best locations of the ‎CO are identified along the building height to maximize energy ‎absorption and dissipation. For validation, the model is ‎compared with the case of a uniform shear core, and the ‎results are shown to be consistent with previous studies.‎‏ ‏Quantitative results indicate that when the shear core has no ‎discontinuity, the best positions of the CO are approximately ‎‎0.44L, 0.49L, 0.32L, and 0.52L of the building height (L) for ‎uniform, triangular, inverted triangular, and parabolic load ‎distributions, respectively. Furthermore, with increasing values ‎of the parameter γ, which corresponds to greater slenderness in ‎the second segment of the shear core, the best positions shift ‎upward along the building height. In some cases, the best ‎location falls within the first segment of the shear core, similar ‎to the case of a uniform shear core.‎‏ ‏The proposed closed-form ‎solution and the developed utility graphs offer a practical and ‎efficient tool for identifying the initial positioning of CO ‎system during the preliminary design of tall buildings.‎ https://civiljournal.semnan.ac.ir/article_10334.html As the final part of a pavement, asphalt mixtures are aimed to ensure the road users’ safety and comfort and any defect in them can disturb the users. They usually consist of bitumen, aggregates and air (as main components) plus a wide range of additives, among which fibers are more important and attract the attention of researchers because they overcome the tensile weakness of asphalt mixtures and improve their performance features. This research has used multicomponent fibers to modify the properties of asphalt mixtures containing reclaimed asphalt pavement overhauled by waste, engine-oil rejuvenator, and applied the balanced mix-design method to optimize the materials. The dynamic creep test, Illinois Flexibility Index (IFI), indirect tensile strength (ITS), and tensile strength ratio (TSR) were utilized to evaluate the mixtures’ performance. The findings revealed that the incorporation of multi-component polymer fibers improved the rutting resistance of asphalt mixtures by up to 70%, whereas the addition of waste oil decreased rutting resistance by up to 1.5%. Furthermore, the highest IFI values were recorded for the specimens containing waste oil. However, the rejuvenator exhibited a negligible effect on the TSR values. Considering the Balanced Mix Design (BMD) criteria, two mixtures containing 40% reclaimed asphalt pavement (RAP), 0.75% rejuvenator, and 0.8% or 1.2% multi-component fibers were identified as the optimum mixtures in this study. https://civiljournal.semnan.ac.ir/article_10354.html In contemporary steel frame construction, semi-rigid joints are increasingly recognized for their ability to balance internal forces and limit stress concentrations. Most existing studies primarily focus on joints at beam–column intersections, while practical construction often introduces additional joints at mid-span when members are segmented and assembled on site. This research applies a finite element approach with geometric nonlinearity (P–Δ effect) to examine how the location of semi-rigid joints affects the static stability of planar steel frames. Both conventional end-joint configurations and alternative mid-span layouts are analyzed. The model, verified against benchmark results, is then used to explore variations in buckling load, deformation patterns, and moment distribution. The findings show that relocating joints to mid-span can enhance the critical load capacity by more than 230% in certain cases, emphasizing the structural significance of connection positioning. Based on these insights, practical recommendations are proposed for prefabricated steel structures with non-traditional connection arrangements. https://civiljournal.semnan.ac.ir/article_10511.html This study investigates the optimal seismic design of a six-story steel frame equipped with three Strongback bracing configurations, characterized by brace-to-beam intersection ratios of , , and  of the span. A Genetic Algorithm (GA) developed in MATLAB was integrated with OpenSees to perform linear static analyses while enforcing a set of design constraints, one of which is a newly introduced drift-uniformity constraint aimed at regulating the distribution of inter-story drifts. A comparative assessment of the three configurations reveals distinct behavioral trends. In the unconstrained optimization, the differences in total structural weight among the configurations remain moderate 0.61% between  and  span, 12.27% between  and , and 11.73% between  and . When the drift-uniformity constraint is included, these differences increase to 4.17%, 25.56%, and 28.55%, respectively, highlighting the pronounced sensitivity of Strongback systems to geometric configuration and showing that brace-to-beam intersection location plays a decisive role in their stiffness-redistribution behavior. The effect of the drift-uniformity constraint varies across the three configurations: it leads to weight reductions of 2.47% and 6.95% in the - and -span arrangements, respectively, while producing a moderate increase of 14.96% for the    span case. Despite this variation, all three systems exhibit improved drift profiles when the constraint is applied. Overall, the findings demonstrate that geometric configuration strongly influences the efficiency of Strongback action, and the proposed drift-uniformity constraint serves as an effective and novel design feature capable of refining drift distribution while maintaining competitive structural weight. https://civiljournal.semnan.ac.ir/article_10520.html During the occurrence of various earthquakes, the formation of local cracks in the connections of the steel frames is regarded as a main problem. Hence, scholars have paid a special attention to the application of steel frames with semi-rigid connections. So far, the frames with semi-rigid connections are rarely utilized, which is mainly due to their high drift rate. In the present article, the impact of semi-rigid connections on the dual-steel frames with various bracing systems was assessed using non-linear dynamic analysis. For accomplishing the analysis, the PERFORM 3D Software was used and the bilinear models were used for modelling the behavior of frames' members. The parameters investigated include maximum base shear, period, frames' drift and energy depreciation of dual systems. The obtained results indicated that the semi-rigid connections lead to decrease in the base shear, while the braces of dual system compensate the increase of drift resulted from utilization of semi-rigid connections. https://civiljournal.semnan.ac.ir/article_10545.html This study demonstrates that Textile-Reinforced Mortar (TRM) systems offer a practical, cost-effective, and sustainable solution for improving the seismic safety of unreinforced masonry (URM) walls, both for post-earthquake repair and preventive retrofitting. TRM significantly enhances load-bearing capacity, ductility, and energy dissipation, addressing the urgent need for resilient and compatible strengthening techniques in earthquake-prone areas.Experimental results reveal that TRM reinforcement increases in-plane load-bearing capacity by 180% in repaired walls and up to 230% in retrofitted walls compared to unreinforced specimens. Displacement capacity under cyclic loading improves by 35% for repaired and 20% for retrofitted walls, while ductility, shear strength, and energy dissipation improve by factors of up to 5.0, 4.8, and 1.1, respectively. Digital image correlation (DIC) and finite element modeling confirm a shift in failure mode from shear to flexure-dominated mechanisms, resulting in more uniform crack distribution and reduced local damage concentration. Comparison with theoretical models such as ACI 549.4R-20 and Eurocode 8 validates the reliability of the methods used. These findings provide engineers and practitioners with a robust, evidence-based framework to select and design TRM interventions that enhance the seismic resilience of both existing and new masonry structures, especially in high seismic risk regions.