MANUFACTURING METHOD OF STEEL MAKING SLAG ROADBED MATERIAL

PROBLEM TO BE SOLVED: To manufacture a steel making slag roadbed material extremely low in expansibility at high productivity.SOLUTION: For a steel making slag a, which is pulverized to have particle size with percentage of particle diameter of 40 mm or less of 80 mass% or more, by increasing or decreasing a fine particle and fine powder component under conditions of (i) classifying a part of the steel making slag a by sieve x with sieve mesh of 10 mm or less to reduce the fine particle and fine powder component and mixing the same with a remainder of the steel making slag a or (ii) adding the fine particle and the fine powder component obtained by classifying the steel making slag which is pulverized to particle size with percentage of particle diameter of 40 mm or less of 80 mass% or more by sieve x with sieve mesh of 10 mm or less in advance to the steel making slag a and mixing them, compression steam aging is conducted after adjusting particle size distribution of the steel making slag a so that Fuller index becomes 0.4 to 0.6 when the particle size diameter of the steel making slag a is approximated with Andreazen curve equation. Thereby a steel making slag roadbed material having reduced expansibility to a minimum level which can be reached with an applied aging condition at high productivity.SELECTED DRAWING: Figure 7 【課題】膨張性が極めて低い製鋼スラグ路盤材を高い生産性で製造する。【解決手段】粒径４０ｍｍ以下の割合が８０mass％以上となる粒度に破砕された製鋼スラグａについて、（i）製鋼スラグａの一部について篩目が１０ｍｍ以下の篩ｘで分級することで細粒・微粉分を減じた後、製鋼スラグａの残部と混合する、若しくは、（ii）以前に、粒径４０ｍｍ以下の割合が８０mass％以上となる粒度に破砕された製鋼スラグを篩目が１０ｍｍ以下の篩ｘで分級することで得られている細粒・微粉分を、製鋼スラグａに加えて混合する、の条件で細粒・微粉分を増減することにより、製鋼スラグａの粒度分布をAndreazenの曲線式で近似した場合に、Fuller指数が０．４〜０．６となるように製鋼スラグａの粒度分布を調整した後、加圧蒸気エージングを施す。これにより、適用したエージング条件で到達し得る最低レベルにまで膨張性を低減した製鋼スラグ路盤材を高い生産性で製造することできる。【選択図】図７