Strength development of slag and ternary blend concrete

Abstract

Ground granulated blast furnace (GGBF) slag is increasingly used in concrete construction due to its technical and economic benefits. This paper describes the strength development of 3 grades of plain cement concretes, portland blast furnace slag (slagment) concretes and concretes in which 15 and 35% of slagment was replaced by flyash (ternary blends). These concretes were cured in standard and nonstandard curing conditions using standard and nonstandard cylindrical specimens. The straight replacement of portland cement by slagment (65% cement and 35% slag) gave higher strength for low to medium strength concretes (20 and 35 MPa). The results also suggest that the strength of the concretes made with slagment was less affected under inadequate curing conditions as compared to the strength of the plain cement concretes. It was also found that the indicated strength of the smaller cylinders (75×150 mm) was adversely affected in the drying curing regimes whereas it was only marginally different from the strength of 150×300 mm cylinders under continuous fog curing. For all the concretes tested, initial curing for 7 days seems to be the most appropriate as it is both practicable and gives adequate strength.