Department of Civil Engineering,University of Kurdistan
Abstract
The behavior of concrete structures that are exposed to extreme thermo-mechanical loading
is an issue of great importance in nuclear engineering. The structural re-safety capacity of concrete
is very complicated because concrete materials have considerable variations. Constitutive models and
relationships for preloaded Normal and High Strength Concrete (NSC and HSC) subjected to re are
needed, which are intended to provide ecient modeling and to specify the re-performance criteria
of the behavior of preloaded concrete structures exposed to re. In this paper, formulations for
estimating the parameters a ecting the behavior of uncon ned preloaded concrete at high temperatures
are proposed. These formulations include residual compression strength, initial modulus of elasticity,
peak strain, thermal strain, transient creep strain and the compressive stress-strain relationship at elevated
temperatures. The proposed constitutive models and relationships are veri ed with available experimental
data and existing models. The proposed models and relationships are general and rational, and have good
agreement with the experimental data. More tests are needed to further verify and improve the proposed
constitutive models and relationships.
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