This study focused on improving the durability of concrete infrastructures located in marine environments. When structures made of concrete are exposed to a marine environment, the combined effects of mechanical and chemical actions, such as attacks from sulfate and chloride, may deteriorate the material, then cause corrosion of the embedded reinforced steel bars, and finally result in shortening of the service life of the structure. Therefore, proposed in this work is a method mainly focused on improving the strength and durability of concrete composed with slag cement as a binder, which due to its pozzolanic reaction is commonly applied in construction projects in marine environments. The durability of slag cement mortar can be improved through the application of bentonite material by utilizing bentonite’s very finely divided form and its reactivity to sulfate so that the larger capillary pores in concrete can be filled. It was found that a slight (approximately 0.25%) replacement of slag cement with bentonite material effectively improved the durability of the slag cement mortar in terms of moisture absorption, compressive strength, and weight loss after a sulfate resistance test and the evaluation for chloride permeability.
