الملخص الإنجليزي
Title: Numerical modelling on the behaviour of concrete-filled steel tube (CFST) with
ferrochrome slag as a fine aggregate at elevated temperatures.
Since laboratory testing is costly and requires considerable amount of time especially
in concrete tests, numerical simulation becomes a matter of great interest in the last
few decades. Finite element modelling method using computers permits the
simulation of structural elements composed of concrete and high strength concrete. On
the other hand, modelling the response of concrete containing waste materials and
industrial by-products is difficult due to the deficiency in the definition of material
properties contrasting normal and common types of concrete. Existing constitutive
models for concrete materials do not account for the presence of aggregate
replacement such as Ferrochrome slag (FCS). FCS is an industrial by-product of the
ferrochrome manufacturing and one of the waste materials that is used in various
construction applications. As experimental tests were already performed on FCS
concrete that is used in concrete-filled steel tube (CFST) composite column, it is
necessary to further investigate the behaviour of this type of concrete utilizing finite
element modelling. This research focuses on the numerical simulation of concrete filled steel tube (CFST) stub column with ferrochrome slag as a fine aggregate after
exposure to elevated temperatures. The study aims to investigate the behaviour of such
columns at ambient temperature and under fire conditions through finite element
modelling and simulation. The numerical models were validated against previous
experimental data, and parametric studies were conducted to assess the effect of
various factors, such as steel tube thickness and concrete strength. Modifications on
existing concrete stress-strain relations after cooling from high temperatures were
proposed to consider confinement and FCS aggregate replacement. The results are
matching well with experiment at normal and high temperature in terms of failure
mode, ultimate load capacity and overall behaviour trend. The outcomes of this
research can help in understanding the behaviour of concrete-filled steel tube stub
columns with ferrochrome slag as a fine aggregate and aid in the design of
exceptional/innovative fire-resistant structures that contains new type of materials.
