Title: Spalling properties of High Strength Concrete Mixed with Various Mineral Admixtures Subjected to Fire

Author(s): Cheon-Goo Han, Min-Cheol Han, and Young-Sun Heo

Publication: IJCSM

Volume: 2

Issue: 1

Appears on pages(s): 41-48

Keywords: high strength concrete; spalling; polypropylene fiber; mineral admixture

DOI:

Date: 6/30/2008

Abstract:
This study investigates the spalling properties of high strength concrete designed with various types of mineral admixture and diverse content ratios of polypropylene (PP) fiber. Experimental factors considered in series? are four pozzolan types of mineral admixture and series? consists of three shrinkage reducing types of mineral admixture. PP fiber was added 0.05, 0.10 and 0.15vol. % in each mixture of series? and series?, so that totally 27 specimens including control concretes in each series were prepared. Test results showed that the increase of fiber content decreased the slump flow of fresh concrete and increased or decreased the air content depending on the declining ratio of slump flow. For the properties of compressive strength, all specimens were indicated at around 50MPa, which is high strength range; especially all specimens in series ? were 60MPa. Fire test was conducted in standard heating curve of ISO 834 with Ø100×200mm size of cylinder moulds for 1 hour. The specimens incorporating silica fume exhibited severe spalling and most specimens without the silica fume could be protected from the spalling occurrence in only 0.05vol % of PP fiber content. This fire test results demonstrated that the spalling occurrence in high strength concrete was not only affected by concrete strength related to the porosity of microstructure but also, even more influenced by micro pore structure induced by the mineral admixtures.