Title:
Microstructural Changes in High and Ultra High Strength Concrete Exposed to High Temperature Environments
Author(s):
C. Alonso, C. Andrade, E. Menendez, and E. Gayo
Publication:
Symposium Paper
Volume:
229
Issue:
Appears on pages(s):
289-302
Keywords:
fire resistance; high- and ultra-high-strength concrete; microstructure
DOI:
10.14359/14743
Date:
9/1/2005
Abstract:
A concrete exposed to environments of high temperature or directly to fire undergoes microstructural changes that result in loss of mechanical properties. The present paper deals with the study of high-performance concretes (HPC) and ultra high-performance concretes (UHPC) resistance to high temperatures. Microstructural changes are followed up to temperatures of 700°C. Changes on residual permeability and porosity, together with weight losses, due to moisture, binding water, aggregates and fibre transformations, are considered. The study, performed on a wide variety of concretes, indicates that UHPC seem to be less resistant at high temperatures than HPC, but the addition of fibres improves the fire resistance of UHPC.