Title:
High- And Ultrahigh-Performance Concrete: A Systematic Experimental Analysis on Spalling
Author(s):
Eike W. Klingsch, Andrea Frangi, and Mario Fontana
Publication:
Symposium Paper
Volume:
279
Issue:
Appears on pages(s):
1-50
Keywords:
high- performance concrete, ultrahigh-performance concrete, elevated temperature, spalling behavior, tensile strength, compressive strength, experimental analysis, mercury intrusion porosimetry, steel fibers, silica fume.
DOI:
10.14359/51682972
Date:
3/1/2011
Abstract:
Within the last years, high- and ultrahigh-performance concrete has increasingly been used, especially for prefabricated elements. Due to its low porosity, high- and ultrahigh-performance concrete may show extensive explosive spalling in case of fire, leading to loss in cross-section and reducing the load carrying capacity significantly. The paper presents the results of an extensive testing program performed on the spalling behavior of high- and ultrahigh-performance concrete using three different concrete mixtures. The heating rate was selected as the main parameter that was systematically varied. Water evaporation was noticed to have a crucial influence on explosive spalling due to a high pore pressure. Furthermore, two different types of spalling where observed. High heating rates led to spalling close to the heated concrete surface. Low heating rates caused spalling initiated from the core. As simplification it is proposed to model concrete as “a pressure cooker”. The analysis of the test results indicates that the simplified model may become an easy to apply tool for the prediction of spalling.