This study investigates the effect of Local Ground Granulated Blast Furnace Slag (GGBS) with and/or without chemically activators on chloride ingress in hardened OPC Mortar. The used GGBS replaced OPC by 10 and 20%. Three different types of alkali-based chemical activators (sodium silicate, sodium carbonate and lithium hydroxide) were used with the OPC mix containing 20%GGBS. Chloride ingress was assessed by measuring Chloride Penetration Test, as a function of depth (chloride profile). To broaden the understanding, compressive strength, TGA and MIP were conducted. The results reveal that, chloride ingress resistance decreased with increasing local GGBS replacement level without using chemical activators. However; the effect can be enhanced by using chemical activator. The used chemical activators with 20% GGBS mix improve its microstructure. The use of lithium hydroxide as a chemical activator improves chloride ingress resistance for 20% GGBS mix higher than the other used activators (sodium silicate, sodium carbonate).