Maejo International Journal of Science and Technology (May 2010)
Study on the flexural properties of metallic-hybrid-fibre-reinforced concrete
Abstract
This contribution investigates the flexural properties of metallic-hybrid-fibre-reinforced concrete. Two types of fibres were used: amorphous metallic straight fibre characterised as non-slipping fibre due to its rough surface and large specific surface area, and carbon steel hook-ended fibre characterised as slipping fibre. Three types of concrete: control, single-fibre-reinforced and hybrid-fibre-reinforced were prepared. The fibre was incorporated at 20 and 40 kg/m3 for single-fibre-reinforced concrete, and at 20, 40 and 80 kg/m3 for hybrid-fibre-reinforced concrete. The flexural properties were studied using three-point bending tests. From the experimental results obtained with fibre-reinforced concrete containing single fibre, addition of high-bonding amorphous metallic fibre delays the formation of micro-cracks and results in high peak load whereas carbon steel hook-ended fibre contributes towards the flexural toughness (energy absorption capacity) by bridging macro-cracks in the post peak region. The test results on hybrid-fibre-reinforced concrete show that the two metallic fibres when used in hybrid form result in superior performance compared to their single-fibre- reinforced counterparts. Superior performance as a result of fibre hybridisation is interpreted as a positive synergetic effect between the fibres. The procedure of assessing the positive synergetic effect is also discussed.
