Influences of steam and autoclave curing on the strength and chloride permeability of high strength concrete

This paper presents the results of an experimental investigation carried out to evaluate the influences of curing methods and mineral admixtures on the strength and chloride permeability of concrete. Rapid chloride ion penetration tests (ASTM C 1202) were used to measure the chloride permeability of concrete. Test results indicated that steam curing decreased the 28 days compressive strength of plain concrete by 11 %. Incorporating slag, fly ash, and silica fume can significantly mitigate this harmful consequence. After autoclave curing however, all concrete’s strength exceeds 80 MPa. Steam and autoclave curing increase the electrical charge passed through plain cement concrete by 110 and 224 %, respectively, when compared with normal curing. For steam curing, incorporating silica fume is the most efficient means to reduce the chloride permeability of concrete. For autoclave curing however, incorporating 30 % fly ash is the most efficient means to reduce chloride permeability.