Title:
Spalling of High-Strength Silica Fume Concrete in Fire
Author(s):
G. Sanjayan and L. J. Stocks and L. J. Stocks
Publication:
Materials Journal
Volume:
90
Issue:
2
Appears on pages(s):
170-173
Keywords:
beams (supports); drying; fire resistance; fire tests; spalling; high-strength concretes; moisture; slabs; silica fume; T-beams; Materials Research
DOI:
10.14359/4015
Date:
3/1/1993
Abstract:
A fire test was conducted on two specimens, one of high-strength concrete and the other of normal strength concrete. At the time of test, strengths of the normal and high-strength specimens were 27 and 105 MPa (3816 and 15,228 psi), respectively. The specimens were of monolithic beam-slab type (T-beams) with slabs 1.2 m (3.94 ft) wide and 2.5 m (8.20 ft) long. Both specimens were cast on the same day using aggregates, cement, and water from the same source and cured under the same conditions. The specimens were made with three different covers, 25, 50, and 75 mm (0.984, 1.969, and 2.953 in.), and two different thicknesses of slabs, 150 and 200 mm (5.906 and 7.874 in.). The specimens were tested after 3-1/2 months of drying in indoor environment. Explosive spalling was observed in high-strength concrete, while no spalling occurred in normal strength concrete. However, the spalling in high-strength concrete was confined to a region with 75 mm (2.953 in.) cover to steel. It was found that length of the path for moisture to escape also has a significant influence on the spalling of high-strength concrete.