Salt scaling resistance of self-consolidating concrete containing pozzolanic-cements

Although numerous durability investigations on self-consolidating concrete (SCC) have urged partial replacement of cement with pozzolans, contradictory results exist regarding the salt scaling resistance of pozzolanic concrete. Hence, this study was carried out on the salt scaling resistance of binary, ternary and quaternary pozzolanic SCC utilising trass, pumice and silica fume pozzolans in nine mixtures along with two air-entrained ones. The binary, SF10, the majority of ternaries, SF10T10, SF10T20 and SF10P10, and the air-entrained, SF10A3% and SF10T20P20A3% mixtures showed acceptable resistance against salt scaling with scaling lower than 0.8 kg/m², as opposed to the quaternary mixes. The effect of pozzolans on the salt scaling resistance of concrete is highly dependent on the silicon dioxide (SiO₂) + aluminium oxide (Al₂O₃) + iron (III) oxide (Fe₂O₃) content of the pozzolan. Also, microstructural analysis through scanning electron microscopy reflected the presence of ettringite and Friedel’s salt from the scaled surface. Furthermore, except for compressive strength, the ternary and quaternary mixes, SF10T10P10, SF10T20P10, SF10T10P20 and SF10T20P20, performed generally better than the binary one in the rapid chloride penetration test, but they had similar pulse velocity, depth of penetration, water absorption and electrical resistivity.