Recently, many efforts related to the utilization of industrial by-products have been made to reduce carbon dioxide emissions in the construction industry. Of these various efforts, concrete incorporating ground granulated blast furnace slag (BFS) provides many advantages compared to conventional concrete, such as high long-term compressive strength, improved durability and economic benefits because of its latent hydraulic property, and low compressive strength at early curing age. This paper investigates the compressive strength of high-activated ground granulated blast furnace slag blended mortar with slag by-product S type(SBP-S). The results of the experiment revealed that incorporating high-activated ground granulated blast furnace slag would affect the compressive strength of mortar. It was found that increasing the Blaine fineness and replacement ratio of slag by-product S type shows high compressive strength of mortar at early curing age because of its high SiO2 and CaO contents in the slag. It is confirmed that an increase of curing age does not affect the compressive strength of mortar made with slag by-product S type at a high curing temperature. Moreover, it is possible to develop and design concrete manufactured with high-activated ground granulated blast furnace slag as binder considering the acceleration curing conditions and mix proportions.

In this study, effect of types and replacement ratio of alkali activator on compressive strength of ground granulated blast furnace slag mortar has been reviewed. Types of alkali activator are NaOH, Ca(OH)2, Na2SO4, and KOH. Replacement ratio of alkali activator is 7.5, 10, 12.5, and 15%, respectively. As results, under high temperature curing condition, 1 day compressive strength development with NaOH and KOH was higher than that of Ca(OH)2 and Na2SO4. Regardless of types of alkali activator, compressive strength increased with increasing pH. This can be explained by the fact that impermeable film on the surface of slag which is generated when slag contacts water has been destroyed by alkali activator, and this promotes hydration reaction. Also, 1 day age compressive strength of specimen with high temperature curing was higher than that of specimen with standard curing. 28 days age compressive strength of specimen with high temperature curing was less than or equal to that of specimen with standard curing.