Response of concrete to accelerated physical salt attack exposure

Various concrete structures/elements are at risk of physical salt attack (PSA) during service; however, there is currently no standard test method in North America for PSA of cement-based materials. Therefore, an accelerated laboratory test, based on sodium sulfate, was developed in this research to assess the resistance of concrete to PSA. The effects of w/cm, fly ash and two types of nanoparticle (nano-silica [NS] and nano-alumina [NA]) addition on the resistance of concrete to PSA were also investigated. The assessment criteria were based on physical properties (visual appearance, mass loss and penetrability), and the alteration of microstructure by microscopy, thermal and mineralogical analyses. The results showed that the proposed procedure can successfully reflect the performance of concrete under PSA within a relatively short time interval (120 days). Also, adverse effects of higher w/cm (0.5) and nanoparticle addition on the resistance of concrete to PSA were captured.