Producing High Strength Hollow Core Reinforced Concrete Slab with Silica Fume and Polypropylene Fibers

Abstract

The compressive strength and workability of concrete mixes with the same proportion of cement, sand, gravel and water but with different amounts of silica fume and polypropylene fiber admixtures were investigated. The same concrete mixes were used for producing hollow core reinforced concrete (HCRC) slab-strip samples tested for flexural strength under third-point loading. The HCRC slab-strip samples were reinforced with the same number and size of reinforcing bars. Silica fume content of 0%, 5%, 10%, 15% and 20% by weight of cement, in combination with polypropylene fiber at 0 kg , 0.40 kg , 0.60 kg and 0.80 kg per cubic meter of concrete, were added into the concrete mix. Tests demonstrate that there is an optimum combination of silica fume and polypropylene fiber for maximum gain in concrete compressive strength of the concrete mix, and another optimum combination of the same admixtures for optimal gain in flexural strength of the HCRC slab-strip samples produced using the concrete mix.