Ahlul Bayt International UniversityConcepts and Functions in the Building Engineering1320250601Regression Analysis of NSM FRP and FRP Wrapping Effects in Strengthened RC Columns111733840ENMohsen AliShayanfarProfessor, School of Civil Engineering, Iran University of Science and Technology, Narmak, Tehran 16846, IranSolmazAfzaliMohammadGhanooni-BaghaJournal Article<span style="font-size: 11.0pt; line-height: 107%; font-family: 'Times New Roman',serif; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'B Nazanin'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: FA;">In this study, a simple regression-based approach is developed to accurately predict the axial load capacity of RC (Reinforced Concrete) columns strengthened using NSM (Near Surface Mounted) and hybrid FRP (Fiber Reinforced Polymer) methods. The model is trained and validated using a dataset of 112 experimentally tested specimens collected from the literature, including 22 data points from the authors' previous study and 90 additional cases. Key input parameters include column dimensions (width and height), concrete compressive strength (mean 35.1 MPa), longitudinal steel ratio (mean 1.43%), transverse steel ratio, number and properties of NSM FRP and FRP jackets, and load eccentricity ratio (mean 0.18). The dataset was split into 80% training and 20% test sets. Three regression models were developed: (i) full linear regression, (ii) regression with statistically significant features, and (iii) stepwise regression. The stepwise regression model showed the best performance with a Mean Absolute Percentage Error (MAPE) of 10.85% and Root Mean Square Error (RMSE) of 201.91 kN on the test set. This approach eliminates complex trial-and-error procedures and offers a transparent, practical tool for engineers and researchers involved in strengthening RC columns.</span>https://cfbejournal.abu.ac.ir/article_733840_3c7ea72a2c6d9531e234e09558f3e9bd.pdfAhlul Bayt International UniversityConcepts and Functions in the Building Engineering1320250601Investigation of the Feasibility of Using Phosphorus Slag in Concrete Mixtures as a Partial Replacement for Sand731722ENMahdiRezayeeMaster's student in the Department of Civil Engineering, Structures, Ahlul Bayt International UniversityPayamTarighiAssistant Professor, Department of Civil Engineering, Faculty of Technical and Engineering, Ahlul Bayt International University, Tehran, Iran.Journal Article20251106This study investigates the feasibility of using phosphorus furnace slag as a partial replacement for sand in concrete. Characterization of the chemical and physical properties of the slag showed that air-cooled phosphorus slag, with flat and angular particles, specific gravity of 1360-1440 kg/m3, and low water absorption (1-1.5%), has high abrasion resistance and durability against freeze-thaw cycles and mechanical damage, making it suitable for partial replacement of sand. Compressive strength tests of concrete with 20% sand aggregate replacement showed that the strength decreased by 9.5% at 7 days and only 1.8% at 28 days, indicating that the initial negative effects due to changes in particle arrangement and increase in effective surface area are compensated during continued hydration. The partial pozzolanic activity and filling effect of fine particles also contribute to the densification of the microstructure. Slump tests showed that the slump of concrete increased from 40 mm to 45 mm with the replacement of 20% sand aggregate, indicating improved flowability of fresh concrete due to the presence of finer particles, smoother surfaces, and reduced internal friction. Overall, replacing about 20% of the sand aggregate with phosphorus furnace slag is technically feasible, environmentally and economically beneficial, and does not significantly reduce the mechanical or flow performance of the concrete, making it suitable for many structural applications.<br><br><br>https://cfbejournal.abu.ac.ir/article_731722_6740828c9bf7da28d21714ad22ad6d2a.pdfAhlul Bayt International UniversityConcepts and Functions in the Building Engineering1320250601Confinement of FRP-Strengthened Columns131872632810.22034/ijscebg.2025.176320ENAtaHojatkashaniAssistant Professor, Department of Civil Engineering, Islamic Azad University South Tehran Branch, Tehran, Iran.Journal Article20250713In recent decades, buildings have suffered damage due to natural disasters such as earthquakes, floods, and heavy snowfalls. One of the effective methods for reducing damage is the strengthening, rehabilitation, and retrofitting of existing structures. In this context, the use of Fiber Reinforced Polymer (FRP) composites, particularly in concrete structures, has gained significant popularity. The growing use of these materials can be attributed to their distinct advantages over traditional materials such as steel.<br>Parameters such as the orientation, alignment, and number of FRP layers have a considerable impact on the behavior of strengthened columns and are frequently investigated through analytical and experimental studies. The results indicate that increasing the number of FRP layers leads to an improvement in ultimate strength, ultimate displacement, and ductility. Moreover, the layer arrangement of the FRP sheets has a distinct influence on the behavior of reinforced concrete columns.https://cfbejournal.abu.ac.ir/article_726328_859fe6e936a76474ef7fe75d0379a120.pdfAhlul Bayt International UniversityConcepts and Functions in the Building Engineering1320250601Study of the Permeability of Roller-Compacted Concrete in Transportation Projects192772633110.22034/ijscebg.2025.176321ENEsmaeilFallah LajimiMaster’s Student in Transportation Engineering Islamic Azad University, Malard Branch, , Malard, Iran.Journal Article20250713Roller-compacted concrete (RCC) is defined as a dry concrete with zero slump. In recent years, the use of RCC in the construction of dams and road pavements has gained widespread acceptance. This trend is attributed to both technical and economic justifications, leading to its global adoption. However, concerns regarding fluid seepage in roller-compacted concrete dams have always been a critical consideration for designers. Therefore, measuring the permeability of concrete in dams is essential to determine the extent of fluid seepage and to provide a criterion for evaluating the durability of the concrete.<br>The main objective of this research is to investigate the effects of various parameters on the permeability of roller-compacted concrete, including mix design, age of the mixtures, cement content, amount of cementitious materials, water-to-cement ratio, percentage replacement of pozzolan (clash), maximum aggregate size, and the amount of silica fume.https://cfbejournal.abu.ac.ir/article_726331_e729e53a32ea4e946f4dd14fd232187a.pdfAhlul Bayt International UniversityConcepts and Functions in the Building Engineering1320250601The Importance of Urban Elements with Emphasis on Iranian-Islamic Identity and Their Role in Strengthening Tourism (Case Study: Azadi Tower, Tehran)283672633222034/IJSCEBG.2025.176322ENMehshadBakhtiariPhD in Urban Planning, Lecturer at Islamic Azad University, Tehran South Branch, , Tehran, Iran.Journal Article20250713The Formation of Cities and the Role of Urban Elements in Identity and Tourism Cities are continuously connected with various elements that sometimes lead to improvement and other times to destruction and decline. During times of improvement, citizens build monuments or urban elements in different parts of the city based on significant events to commemorate and pass these memories to future generations. Since foreign tourists do not have full awareness of these events, by observing these urban elements, they come to understand the city's identity and the events that have taken place there. It is as if urban elements give identity to the city, distinguishing it from other places and bestowing unique beauty and grandeur upon it. In fact, many countries are recognized and identified by the names of these landmarks. The purpose of this article is to examine the relationship between urban elements and the Iranian-Islamic urban identity and their role in attracting tourists, with an emphasis on Tehran’s Azadi Tower. The research method involves reviewing and analyzing relevant texts and resources. The results indicate that in today’s world, amid a highly competitive tourism market, symbol-making in cities aligned with the culture of the country gives identity to the city and acts as a factor for success in attracting tourists.https://cfbejournal.abu.ac.ir/article_726332_639b9f4b951271e3c8c039acaa7ea2d1.pdfAhlul Bayt International UniversityConcepts and Functions in the Building Engineering1320250601Optimization of the Mix Design of High-Performance Concrete Containing Microsilica and Superplasticizer3747731787ENAlirezaHabibiFull Professor, Department of Civil Engineering, Shahed University, Tehran, IranBehroozFeizi2M.Sc. in Structural Engineering, Department of Civil Engineering, University of Kurdistan, Sanandaj, IranSalimiSalimiM.Sc. in Structural Engineering, Department of Civil Engineering, University of Kurdistan, Sanandaj, IranJournal Article20251028With the ever-increasing use of concrete in construction projects, the demand for concrete with improved properties is continuously growing. In this context, one of the concretes commonly used in specialized structures where high strength is required is High-Performance Concrete (HPC). Among the pozzolanic materials employed to enhance the strength and durability of concrete, microsilica (silica fume) has demonstrated excellent performance. The aim of this study is to optimize the mix design of concrete incorporating microsilica and a superplasticizer. To achieve this goal, an optimization model is first formulated for the mix design of this type of concrete. The development of the model is based on optimization principles combined with experimental results. An effective algorithm is then applied to solve the mix design optimization problem. The proposed method not only automates the mix design process for microsilica- and superplasticizer-based concrete but also minimizes the overall production cost of this type of high-performance concrete.https://cfbejournal.abu.ac.ir/article_731787_a7062ed923ec11aaa00dbce29c447e3f.pdf