Early-age deterioration of concrete due to cracking and higher maintenance cost for poor durability cause serious troubles to concrete structures. Steel slag is a solid waste discharged in large quantities by the iron and steel industry. Steel slag includes a certain scale mineral such as C2S and C3S, and can be applied in cement and concrete as mineral admixtures. When mineral admixtures with steel slag powder and blast-furnace slag powder are mixed into concrete, the performance of concrete can be improved further. Mineral admixtures with steel slag powder as partial replacement for Portland cement in mortar is an effective means for enhancing abrasion resistance. Steel slag powder can be used to reduce cracking in concrete at early age, so that it will improve the durability of concrete structures.