Towards an adequate deicing salt scaling resistance of high-volume fly ash (HVFA) concrete and concrete with superabsorbent polymers (SAPs)

摘要

The deicing salt scaling resistance has been investigated for two types of concrete, i.e., airentrained high-volume fly ash (HVFA) concrete with a 50% cement replacement and non-airentrained concrete containing superabsorbent polymers (SAPs). A full characterization oftheir air void systems from the moment of casting until the freeze/thaw test was also done.Due to the presence of the highly AEA adsorptive fly ash an increased AEA dosage (7.0ml/kg binder) was needed to achieve an adequate air void system in terms of air content andspacing factor to keep salt scaling within acceptable limits. For the novel non-air entrainedconcrete type with SAPs, which are able to absorb up to 500 times their weight in fluids, thesalt scaling resistance is surprisingly high. The microstructural analysis revealed theformation of macro-pores due to these SAPs, creating an air void system as can be found inair-entrained concrete. Another advantage is that the strength of concrete with SAPs is muchhigher than for a conventional air-entrained concrete. This substantiates the further use ofthese SAPs as admixture in precast concrete road elements.