Performance assessment of blended self-compacting concrete with ferrochrome slag as fine aggregate using functional ANOVA

The current study explored the feasibility of re-use of ferrochrome slag (FS), a waste byproduct from the ferrochrome industry as a replacement to fine aggregate in self-compacting concrete (SCC) with cement and fly ash as binders. The study investigated the mechanical and durability characteristics of SCC of M25 grade, incorporating FS in lieu of fine aggregate, up to 60 % replacement levels. Albeit workability of fresh concrete decreased with the increase of FS content, they were within the recommended limits of EFNARC for SCC. Considerable decreases in compressive, tensile and flexural strengths were observed in the mixtures with FS contents above 40 %. Slightly better performances in terms of water absorption, sorptivity, chloride ion permeability and sulphate attack were found in the concretes partially blended with FS. Leaching of chromium (Cr) from FS-incorporated self-compacting concrete samples were within the Indian discharge limits. Microstructural studies were conducted to decipher the arrangement of components in the concrete as well as determine the elemental composition of ferrochrome slag. Functional analysis of variance (ANOVA) was conducted to determine the significance of functional components in explaining the variability of the mechanical properties expressed as continuous functions. The test findings indicate that there is no statistical difference in the compressive strength and split tensile strength as a result of substituting a portion of sand with FS. Nevertheless, a rise in flexural strength is noticed after surpassing a 5 % substitution. •Ferrochrome slag is identified as a waste product during manufacture of ferrochromium alloy.•Self-compacting concrete requires large amount of fine aggregate.•Usage of ferrochrome slag as a replacement to fine aggregate in self-compacting concrete is explored.•40 % replacement of fine aggregate by ferrochrome slag showed superior strength.•The significance of functional components is assessed using Functional ANOVA.