The production of concrete exposed to a chloride-rich environment in splash and spray areas requires special properties. This often includes the use of specific cement types as well as the addition or replacement of cement with supplementary cementitious materials (SCM). However, the most used SCMs, such as fly ash, silica fume and ground blast furnace slags, have become limited in their availability due to industrial changes and their environmental impact. New alternative SCMs providing high resistance against chloride ingress in mortars and concrete are required. This study used granulated copper slag, volcanic ash, brick powder, and metakaolin as SCM in mortars. The alternative SCMs were characterized by their chemical and physical parameters and pozzolanic reactivity (R3-test). Mortars produced from the SCMs were tested on their workability, mechanical strength, and chloride migration performance and compared with references. The chloride migration coefficient was evaluated using the two-electrode method (TEM), specific charge flow rate (SCFR) and rapid chloride migration (RCM) tests. Results showed an increased resistance against chloride ingress for some of the SCMs used as partial cement replacement compared to the references. Based on the results, a service life design can be performed to compare the durability performance of the different SCMs. This would allow the use of alternative tailored SCM for mortars and concretes in splash and spray expositions.