Assessing the Effects of Steelmaking Slag Powder on the Pore Structure and Durability of Concrete

Abstract

This study analyzes the pore structure and durability of concrete according to four different ratios of steelmaking slag powder (SSP). Concrete containing SSP increased the formation of gel and capillary pores due to delayed hydration, and the largest cumulative pore volume was observed when the incorporation ratio was 20%. In terms of durability, the incorporation of SSP had decreased performance compared to concrete without SSP (NN), which was due to changes in the pore structure caused by incorporating SSP. In the case of the freezing and thawing resistance, concrete containing 10% SSP showed a remarkable relative dynamic elastic modulus of more than 80%, and a similar carbonation depth was predicted within 15% of SSP. In addition, the resistance performance of chloride ion migration in concrete with SSP was excellent. Accordingly, it can be utilized as a supplementary cementitious material if the freezing and thawing resistance of concrete containing 15% SSP is secured.

Mechanical and Electrical Characteristics of Lightweight Aggregate Concrete Reinforced with Steel Fibers

“…and durability [32] of concrete based on the replacement ratio; almost no degradation in strength and durability occurred when the replacement ratio of steel slag was within 15%. Based on these findings, concrete mixes were designed in this study by applying the replacement ratio of steel slag at 15% [31][32][33][34][35].…”

“…and durability [32] of concrete based on the replacement ratio; almost no degradation in strength and durability occurred when the replacement ratio of steel slag was within 15%. Based on these findings, concrete mixes were designed in this study by applying the replacement ratio of steel slag at 15% [31][32][33][34][35]. Additionally, variables were set by substituting the coarse aggregate with bottom-ash-based lightweight coarse aggregates to reduce the weight of concrete containing steel slag.…”

“…The water-to-binder ratios were 0.325 and 0.200, and steel slag powder was used as the binder. Several studies used steel slag powder to assess the microstructure [31,32], strength [33][34][35],…”

“…The cement was Type I ordinary Portland cement with a Blaine of 3413 cm 2 /g. The steel slag powder had a Blaine of approximately 4893 cm 2 /g, and it was obtained by pulverizing steel slag aggregate using ball mill equipment (Chemius Korea Co. Ltd., Gurye, Korea) [32,34]. River sand was used as the fine aggregate.…”

“…When steel slag was added, the amount of cement used was reduced, delaying the hydration reaction and limiting portlandite (Ca(OH) 2 ) production [35,46]. Many researchers [31][32][33][34][35] have reported that incorporating steel slag delays the hydration reaction of concrete based on the X-ray diffraction (XRD), mercury intrusion porosimetry (MIP) analyses, and penetration resistance tests, which determine the initial and final sets.…”