EFFECT OF HIGH TEMPERATURE AND COOLING REGIMES ON THE COMPRESSIVE STRENGTH AND PORE PROPERTIES OF HIGH PERFORMANCE CONCRETE

Abstract This paper describes the behavior of high performance concrete (HPC), compared with normal strength concrete (NSC), after subject to different high temperatures (800 and 1100°C) and cooling regimes (gradual and rapid cooling). Deterioration of compressive strength of the concrete was measured. The results obtained showed that the strength of both the HPC and NSC reduced sharply after their exposure to high temperatures. Thermal shock due to rapid cooling caused a bit more deterioration in strength than in the case of gradual cooling without thermal shock. However, thermal shock did not significantly increase the spalling of HPC. Mercury intrusion porosimetry (MIP) tests were carried out to measure changes in the pore size distribution in the concrete. Test results showed that the pore volume in the HPC increased much more than that in the NSC. A significant change in the cumulative pore volume was observed and the difference in cumulative pore volume between the two cooling regimes was less after subject to the peak temperature of 1100°C when compared with that of 800°C peak temperature.

[1]  Gabriel A. Khoury,et al.  Compressive strength of concrete at high temperatures: a reassessment , 1992 .

[2]  Z. Sawicz,et al.  Changes in the structure of hardened cement paste due to high temperature , 1984 .

[3]  C. Castillo,et al.  Effect of transient high temperature on high-strength concrete , 1990 .

[4]  G Sanjayan,et al.  SPALLING OF HIGH-STRENGTH SILICA FUME CONCRETE IN FIRE , 1993 .

[5]  Breitenbücher.  Developments and applications of high-performance concrete , 1998 .

[6]  The Effect of Elevated Temperatures on the Moisture Migration and Spalling Behavior of High-Strength and Normal Concretes , 1997 .

[7]  G. A. Khoury,et al.  Material and environmental factors influencing the compressive strength of unsealed cement paste and concrete at high temperatures , 1993 .

[8]  J. P. Hurst,et al.  Analytical Approach for Investigating the Causes of Spalling of High-Strength Concrete at Elevated Temperatures. , 1997 .

[9]  Sammy Chan,et al.  Comparison between high strength concrete and normal strength concrete subjected to high temperature , 1996 .

[10]  Takeo Hirashima,et al.  MECHANICAL PROPERTIES OF HIGH STRENGTH CONCRETE AT HIGH TEMPERATURES , 1999 .

[11]  R. Dheilly,et al.  Effect of microstructure on the mechanical and thermal properties of lightweight concrete prepared from clay, cement, and wood aggregates , 1998 .

[12]  Binsheng Zhang,et al.  Relationship Between Pore Structure and Mechanical Properties of Ordinary Concrete Under Bending Fatigue , 1998 .