Title : PERFORMANCE OF CONCRETE REINFORCED WITH COMBINATIONS OF AMORPHOUS METALLIC AND CONVENTIONAL STEEL FIBRES
Authors : Sunitha K Nayar, RavindraGettu
Publication : 8 - 10, October 2015
Volume : 2
Pages :
Price : 250
Abstract : Applications pertaining to fibre reinforced concrete generally take advantage of the higher ductility and crack control imparted to the concrete by the fibres. Though the commonly used types and dosages of fibres impart higher post cracking capacity, the improvement in flexural strength is marginal. However, it has also been established that fibres with very high bonding characteristics and if present in sufficient quantity, a substantial increase in flexural strength is possible, e.g., amorphous metallic fibres (AMF). However, low dosages of AMF have limited effect on the concrete behavior at larger deflections. On the contrary, conventional macro steel fibers, at comparable dosages, improve ductility and the post-cracking performance resulting in a long pseudo-ductile regime in the load-deflection response of the concrete. In order to investigate the potential of AMF and SF in combination, a test program was conducted based on flexural toughness testing of unnotched beams. The parameters evaluated include the flexural strength, equivalent flexural strength and equivalent flexural strength ratios. The performance of the hybrid mix was evaluated for any possible synergy using the law of mixes. Tests on mixes with various dosages of AMF (10 and 20 kg/m3) and a single dosage of SF (15 kg/m3) were carried out, along with mixes with only SF and plain concrete. The results showed a significant increase in the flexural strength of concrete with the addition of AMF, even at low dosages. The performance of concretes with the hybrid combinations is significantly enhanced due a synergistic effect between the AMF and SF. Implications of the use of these hybrid mixes for flooring and pavement design are discussed.