Effect of silica fume and fly ash on fatigue and impact strength of fibre-reinforced concrete

The utilisation of by-products such as silica fume and fly ash in the production of concrete produces concrete with desirable performance characteristics. However, these materials can also impair the ability of concrete to resist dynamic loading, a property that can be restored using fibre reinforcement. This paper reports the results from a programme of laboratory research, which has been conducted to investigate the effect of silica fume and fly ash on the fatigue strength and impact resistance of fibre-reinforced concrete. In this work, six mixtures were investigated. The control mix was produced without fibre or cement replacement materials. The other five mixes were reinforced with 1% (by volume) steel fibres. The effects of fly ash and silica fume were investigated at two replacement levels on a weight-to-weight basis. For fly ash, the replacement levels were 25% and 50%, whereas the replacement percentages for silica fume were 5% and 10%. The results suggested that the effect of steel fibre on the flexural fatigue strength was more significant than the effect of the cement replacement materials. The use of silica fume and fly ash slightly improved the flexural fatigue behaviour. As a conservative approach, it was concluded that the fatigue strength of mixes containing silica fume or fly ash is at least comparable to that of Portland cement FRC. The use of steel fibre had a negligible effect on the first-crack impact resistance, yet it enhanced the ultimate impact resistance by more than 200%. The mix including silica fume exhibited a 50% increase in both first-crack and ultimate impact resistance of the FRC. The effect of fly ash on the impact resistance was insignificant. For the covering abstract see ITRD E145817

  • Authors:
    • BADR, A
    • PLATTEN, A K
  • Publication Date: 2006

Language

  • English

Media Info

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Filing Info

  • Accession Number: 01155351
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Apr 23 2010 11:02AM