Premature degradation of ordinary Portland cement (OPC) concrete infrastructures is a
current and serious problem with overwhelming costs amounting to several trillion dollars. The use
of concrete surface treatments with waterproofing materials to prevent the access of aggressive
substances is an important way of enhancing concrete durability. The most common surface
treatments use polymeric resins based on epoxy, silicone (siloxane), acrylics, polyurethanes or
polymethacrylate. However, epoxy resins have low resistance to ultraviolet radiation while
polyurethanes are sensitive to high alkalinity environments. Geopolymers constitute a group of
materials with high resistance to chemical attack that could also be used for coating of concrete
infrastructures exposed to harsh chemical environments.
This article presents results of an experimental investigation on the resistance to chemical attack (by
sulfuric and nitric acid) of several materials: OPC concrete, high performance concrete (HPC),
epoxy resin, acrylic painting and a fly ash based geopolymeric mortar. Three types of acids, each
with high concentrations of 10%, 20% and 30%, were used to simulate long term degradation by
chemical attack. The results show that the epoxy resin had the best resistance to chemical attack,
irrespective of the acid type and acid concentration.