Research on the resistance to saline soil erosion of high-volume mineral admixture steam-cured concrete

Abstract

The reasonable steam curing regime and the resistance to saline soil erosion of high-volume fly ash steam-cured concrete, high-volume ordinary slag steam-cured concrete and high-volume ultra-fine slag steam-cured concrete were studied by determining the demoulding strength, reaction degree, strength development law, chloride ion permeability, connected porosity, and sulfate attack resistance. The results show that although high-volume fly ash steam-cured concrete with the ideal demoulding strength and good resistance to chloride ion permeability can be obtained via properly reducing water-binder ratio and simultaneously prolonging steam curing time, its later-age strength development and the resistance to sulfate attack are not significantly improved compared with plain cement steam-cured concrete. High-volume ordinary slag steam-cured concrete with both ideal demoulding strength and great strength development at later ages can be obtained via only appropriately prolonging the steam curing time. Ordinary slag tends to enhance the saline soil resistance of steam-cured concrete more significantly than fly ash. High-volume ultra-fine slag steam-cured concrete with the ideal demoulding strength and good resistance to chloride ion permeability and sulfate attack can be obtained without or via slightly prolonging the steam curing time. But ultra-fine slag does not have a better effect on the later-age performance of steam-cured concrete than ordinary slag. Compared with high-volume fly ash or ordinary slag steam-cured concrete with similar demoulding strengths, high-volume ultra-fine slag steam-cured concrete has the better resistance to saline soil erosion.