Abstract
Many modern concrete structures incorporating high-strength concrete may be susceptible to heat-induced explosive concrete spalling during fire. This presents a major challenge for contemporary concrete designers who often wish to use high-strength concrete in various structural engineering applications. The concrete industry is only just beginning to grapple with the implications of increased spalling of modern concrete mixes. There is widespread disagreement on the relative importance of the physical mechanisms which may trigger or exacerbate heat-induced concrete spalling, and while it has been shown that introducing polypropylene (PP) fibres into the fresh concrete reduces the likelihood of spalling during furnace tests, the reasons for PP fibre effectiveness remain a matter of debate within the research community. This article presents a comprehensive experimental study on heat-induced concrete spalling, with an emphasis on assessing the effectiveness of various types and doses of PP fibres. High-strength, self-consolidating concrete mixes in which PP fibre type, cross section, length, supplier, and dose were varied, were tested under simulated standard furnace exposures. It is shown that increased PP fibre dose, which is currently the sole parameter prescribed by available design guidelines, mitigates spalling. However PP fibre cross-section and length may also be important for PP fibre effectiveness in mitigating heat-induced concrete spalling during fire.
Original language | English |
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Pages (from-to) | 32 |
Number of pages | 37 |
Journal | Concrete In Australia |
Volume | 40 |
Issue number | 3 |
Publication status | Published - Sept 2014 |
Keywords / Materials (for Non-textual outputs)
- Concrete, fire, spalling