Seawater resistance of alkali-activated concrete

This chapter discusses the durability of different geopolymer concretes (GPCs) in the marine environment. For this aim, aggressive ion compositions of the marine environment in several regions are summarized, and the chemical attacks and deterioration mechanisms of GPCs are investigated in detail. The alkali activator type, raw material type and content, alkali content, modulus of sodium silicate, the molarity of sodium hydroxide, water content, curing methods, and temperature have significant influences on the resulting mechanical and durability performance. The permeability, capillary sorptivity, chloride diffusion, and chloride binding capacity of a GPC determine the degree of deterioration. In addition, the visual appearance, surface erosion, efflorescence formation, microstructural variations, weight and mechanical strength changes of different GPC specimens are comprehensively examined. Finally, the short-term laboratory and long-term in situ durability performances of GPC specimens are thoroughly investigated. The obtained results are compared to ordinary Portland cement concretes for the structural utilization of GPCs in the marine environment. © 2022 Elsevier Ltd All rights reserved.