English abstract
Steel slag (SS) and ferrochrome slag (FCS) are industrial by-products that are produced in large
quantities in Oman. According to recent studies, concrete containing these by-product materials
as an aggregate has better mechanical properties than conventional concrete. However, very
limited studies concentrated on the durability and environmental effect of concrete containing
ferrochrome slag and steel slag as aggregates. In this study, locally produced FCS was used as
coarse and fine aggregates in the production of concrete, while the SS was used as a coarse
aggregate in the production of concrete. Therefore, the effect of using FCS aggregates to
replace conventional aggregates (25%, 50%, 75%, and 100%) and SS aggregate to replace
conventional coarse aggregate (50% and 100%) on the properties of concrete (C35) was
investigated. The physical, chemical and mechanical properties of the slag materials and
natural aggregates were determined to verify that they were within the standard limits. The
concrete mixes were assessed in term of workability, density, compressive strength, splitting
strength, flexure strength, modulus of elasticity, bond strength, chloride permeability, thermal
conductivity, ultra-sonic pulse velocity, porosity, wet/dry cycles, acid and sulphate resistance,
and corrosion resistance by impressed voltage test. The presence of FCS and SS aggregates
improved the mechanical properties of the slag concrete compare to the conventional concrete.
Porosity was remarkably reduced with the incorporation of various content of FCS aggregates.
On the other hand, the porosity slightly increased with the increase of SS content. The chloride
permeability of FCS concrete is lower than conventional concrete. On the other hand, SS
concrete shows higher chloride permeability than conventional concrete. The utilization of
slags in the concrete has resulted in increase the thermal conductivity. Higher ultrasonic pulse
velocity was observed in higher content of FCS and SS aggregates. The use of FCS and SS
aggregates enhanced the long-term compressive strength, resulting in better resistance to
corrosion, wet/dry cycles, acid and sulphate attacks. The investigated results demonstrate that
FCS and SS have a potential to be used an as an alternative aggregate in the production of
environmentally friend and structurally applicable concrete.
