Flexural response of vertically cast steel fiber reinforced concrete members

Abstract

The presence of the short steel fibers dispersed uniformly in concrete improves its inherent flaws and makes it a versatile structural material. The improvement in material properties depends upon the alignment of the fibers in concrete members caused during their casting; those aligned along the principle tension trajectory of the beams are most efficient among all the fibers present therein and other fibers control their shear response. An attempt is made to quantify the effect of the mould position (vertical or horizontal) during the casting process on the flexural response of steel fiber reinforced concrete (SFRC) members. An analytical model is also presented to predict the response of the members in case some of the design constraints require their casting in the vertically placed moulds, such as for walls, columns, etc. instead of the routine horizontal position. A significant reduction in flexural strength and toughness of the SFRC members is observed if these were cast vertically instead of the horizontal position; additionally, they exhibit wider flexural cracks. Their shear capacity remained almost unchanged.