Effect of mould type on flexural strength of self-compacting steel fibre-reinforced concrete

Abstract

Fresh self-compacting steel fibre-reinforced concrete (SCSFRC) of strength class 30 MPa was casted into the small (100x100x400 mm3) and large (100x300x400 mm3) moulds. The large specimen was splitted into three small identical ones (100x100x400 mm3). All of the specimens were subjected to third-point bending in as-cast direction. Flexural strength of SCSFRC obtained from small specimens (100x100x400 mm3) yielded 10% higher than that from large specimens of the same size. While flexural strength defined by the small specimens (100x100x400 mm3) that were cut from the large specimens was almost the same. When pouring fresh SCSFRC into the small mould, steel fibres were orientated along with the flow of the fresh concrete due to the wall-effect and the velocity profile. Likely, this phenomenon did not occur in the case of large mould. This was the main reason why flexural strength was influenced by mould type.
Keywords: Self-compacting steel fibre-reinforced concrete, fibre orientation, mould type, wall effect, flexural strength