Salman Ban Fadhil, Allawi Abbas A
Department of Civil Engineering, University of Baghdad, Baghdad, 17001, Iraq.
Heliyon. 2024 Nov 20;10(23):e40504. doi: 10.1016/j.heliyon.2024.e40504. eCollection 2024 Dec 15.
In modern constructions, the use of composite column has become widespread used due to the modern requirements of tall buildings for reducing column cross-sections and construction dead loads. To verify the use of alternative materials employed in construction instead of steel sections, GFRP I-section was utilized in this study for this purpose due to its properties like light weight, corrosion resistance and high strength. The research aims to study the influence of using different types of encased I-section (steel and GFRP) in addition to steel bars in the reinforced concrete composite columns. Twelve rectangular reinforced concrete specimens were tested under varying load conditions. All specimens were divided into three groups depending on the type of material encased. The first group was the reference group, which was reinforced with longitudinal steel bar only. Each group contained four specimens tested under different loading conditions, the first column was subjected to concentric load, the second and third columns were subjected to eccentric loads (e = 25 mm and 50 mm), while the last specimen was subjected to flexural loading (with a two-point load). All the specimens were tested under different loads to investigate composite column behavior and achieve interaction diagram. The experimental findings that columns subjected to concentric load and encased with I -section (steel and GFRP); showed an increase in failure load by 10 % and 8.4 % respectively, relative to reference column. Additionally composite columns tested under eccentric load with eccentricities 25 mm and 50 mm and encased with I -section (steel and GFRP); failure load were increased by 16.6 %, 14.4 %, 25 % and 19.7 % respectively, relative to reference columns. While specimens under flexural load encased with I -section (steel and GFRP); appear that an increase in ultimate load by 81 % and 62 %, respectively, relative to reference specimen. These results show a significant improvement in specimen strength when encased with steel and GFRP. The composite column encased with steel was stronger than column encased with GFRP. Lateral deformation was recorded and show it directly proportion with eccentricity, which increased significantly at an eccentricity of 50 mm. Additionally, analytical results was utilized by FE to emulate the experimental results of the tested specimens, modeling done by using ABAQUS software version 6.14. The FE analysis results display a good agreement with the experimental results for (ultimate strength, strain, modes of failure, lateral and axial deformation) when compared with the experimental specimens.
在现代建筑中，由于高层建筑对减小柱截面尺寸和建筑恒载的现代要求，组合柱的使用已变得十分普遍。为了验证建筑中使用替代材料（而非钢截面）的可行性，本研究采用玻璃纤维增强塑料（GFRP）工字形截面，因其具有重量轻、耐腐蚀和强度高等特性。该研究旨在探讨在钢筋混凝土组合柱中，除了钢筋之外，使用不同类型的内置工字形截面（钢和GFRP）的影响。十二个矩形钢筋混凝土试件在不同荷载条件下进行了测试。根据内置材料的类型，所有试件分为三组。第一组为参考组，仅用纵向钢筋加固。每组包含四个在不同加载条件下测试的试件，第一根柱承受轴心荷载，第二根和第三根柱承受偏心荷载（e = 25mm和50mm），而最后一个试件承受弯曲荷载（两点加载）。所有试件在不同荷载下进行测试，以研究组合柱的性能并获得相互作用图。实验结果表明，轴心受压且内置工字形截面（钢和GFRP）的柱，相对于参考柱，破坏荷载分别增加了10%和8.4%。此外，在25mm和50mm偏心距下承受偏心荷载且内置工字形截面（钢和GFRP）的组合柱，相对于参考柱，破坏荷载分别增加了16.6%、14.4%、25%和19.7%。而在弯曲荷载下内置工字形截面（钢和GFRP）的试件，相对于参考试件，极限荷载分别增加了81%和62%。这些结果表明，用钢和GFRP包裹时，试件强度有显著提高。内置钢的组合柱比内置GFRP的柱更强。记录了横向变形，结果表明其与偏心距成正比，在偏心距为50mm时显著增加。此外，利用有限元分析结果来模拟测试试件的实验结果，使用ABAQUS 6.14软件版本进行建模。与实验试件相比，有限元分析结果在（极限强度、应变、破坏模式、横向和轴向变形）方面与实验结果显示出良好的一致性。
