Investigation on the Viability of Using Fly Mesh as External Confinement for High Strength Concrete Columns
It is well documented that high strength concrete (HSC) columns are subject to early spalling of the concrete cover and this spalling leads to strength reduction. For years, engineers have been faced with the challenge to retrofit or strengthen existing deficient reinforced columns. Many theoretical and experimental studies have been carried out over the last few decades on fiber reinforced polymer (FRP), proving that FRP composite jackets can significantly increase the compressive strength and strain ductility of concrete columns. The need of investigation on the potential of other external wrapping materials has arisen to find more economic alternatives. A new idea about pre-stalling relatively cheap materials such as household fly screen in the formwork of columns is investigated in this study. Fibre glass fly mesh (FGFM) and standard aluminium fly mesh (SAFM) were used as external confinement to reinforced high strength concrete columns. The specimens, including a group of unconfined HSC columns, were tested under concentric, 25 mm and 50 mm eccentricity, and pure bending loads. The testing results of the specimens have shown that FGFM and SAFM significantly improved the ductility of columns under concentric loading, but the significance decreased with the increase of eccentricity. Moreover, FGFM outperformed SAFM in terms of ductility. The testing results also indicated that FGFM and SAFM can increase the load capacity of the columns.