Abstract
The objective of this study was to develop basic oxygen furnace slag (BOFS) blended with Fly Ash (FA) based masonry blocks that can be used in building and construction. The effect of variation of FA, potassium hydroxide (KOH) concentration, curing temperature, solid-liquid ratio on the Unconfined Compressive Strength (UCS) was investigated. The optimum conditions for synthesis of BOFS/ FA based masonry blocks was found to be 9 M KOH concentration, 20% Solid- liquid (S/L) and 1:5, FA:BOFS mixing ratio and curing temperature 80 ℃. The masonry block prepared under aforementioned optimum condition achieved unconfined compressive strength (UCS) of 9.67 MPa. Characterization of the masonry blocks was done using X-Ray Diffraction (XRD) analysis, X-Ray Fluorescene (XRF) analysis. The major phase identified in XRD pattern for BOFS was larnite whereas for FA was glassy aluminosilicate. Optimum BOFS/FA masonry block had new phase which is zeolite (Philipsite) responsible for higher UCS of the construction block. The produced construction block met the minimum requirements for ASTM C34-13, C129-14a and South African standard (SANS227: 2007).