This research explores the durability performance of ternary blended concrete made using industrial by-products ground granulated blast furnace slag (GGBFS) and microfine (MF) as partial replacements for ordinary Portland cement (OPC), along with manufactured sand (MS) as a sustainable alternative to river sand. M30-grade concrete mixes were prepared, including a control mix and a ternary blend (G3M4) comprising 30 % GGBFS, 20 % MF, and 50 % OPC. Durability assessments were carried out by exposing the specimens to acidic (5 % HCl + 5 % H2SO4) and saline (10 % NaCl) environments. Compressive strength and weight loss were evaluated at 28, 56, 90, and 180 days. The G3M4 mix showed significantly better performance, with lower weight reduction (7.64 % in acid and 4.98 % in salt exposure) than the control mix (12.99 and 5.35 %, respectively). Likewise, strength loss was minimized in the G3M4 mix, recording reductions of 45.41 % under acid and 6.88 % under salt exposure versus 52.08 and 9.44 % for the control. These improvements are credited to the denser matrix and increased chemical resistance from the combined use of GGBFS and MF. The study highlights the potential of ternary blended concrete with MS in enhancing durability under harsh conditions, promoting more sustainable construction solutions.