Hollow Reinforced Square Concrete Columns under Axial Loading for Sustainable Construction

This study evaluates the axial load performance of hollow square concrete columns relative to plain solid and reinforced solid columns, with attention to material efficiency. A total of ۱۰۰ × ۱۰۰ mm specimens were cast in concrete grades M۱۵, M۲۰, and M۲۵ and tested at selected length to depth ratios. Hollow columns incorporated a centrally placed ۲۰ mm circular void, representing about ۴% material reduction. Reinforced specimens were detailed with ۴Φ۸ mm longitudinal bars and Φ۶ mm stirrups at ۱۰۰ mm spacing. Three samples were tested per configuration under monotonic axial compression to failure. Ultimate load, axial shortening, and failure modes were recorded. Results establish a clear performance hierarchy. Reinforced columns achieved the highest load capacity and deformation resistance, showing strength gains of approximately ۶۰ to ۱۸۰% over non-reinforced specimens. Higher concrete grades contributed an additional ۲۰ to ۴۰% increase in capacity. Hollow columns consistently underperformed, with strength reductions of ۳۰ to ۶۰% compared to equivalent solid columns, largely due to stress concentration around the void. Increased slenderness reduced capacity across all types, most significantly in hollow specimens. Although hollow sections offer modest material savings, their reduced strength limits structural applicability.

کلیدواژه ها:

Hollow concrete columns ، Axial loading ، Sustainable Construction ، Structural performance