Analyzing the effects of pickling sludge and fly ash valorized cement sand bricks

The disposal of Stainless-Steel Pickling Sludge (SSPS) in landfills remains an important issue. Utilizing SSPS as construction material mitigates the negative environmental effects associated with its disposal, providing a sustainable solution. This study investigates co-utilization of SSPS and fly ash as partial substitution of river sand on cement sand bricks properties. Nine cement sand bricks compositions, including control mix, were prepared with varying composition of SSPS, fly ash and river sand. Four compositions were developed with SSPS varied from 2.5 to 10% with fixed fly ash content of 50%. Four additional compositions with varying fly ash content from 40 to 47.5% and varying SSPS 2.5–10% content as partial substitution of river sand were prepared. The developed bricks demonstrated that gradual increment of SSPS (2.5–10%) and reduction of fly ash (47.5–40%) proved incremental to the compressive strength up to 28 MPa. In addition, the morphological analysis using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) were conducted for the compositions. The microstructure analysis showed that with inclusion of fly ash, Mix 2 (M2) compositions revealed a dense microstructure validating the sorptivity results as compared to Mix 1 (M1) compositions. Finally, the cost estimation of the waste valorized bricks as compared to the control bricks was observed to be significantly low. The experiment outcomes concluded adoption of SSPS-fly ash waste valorized bricks as a greener alternative to disposal.