Method for producing anti-bleeding agent for concrete and method for producing cement composition containing the anti-bleeding agent for concrete

摘要

PROBLEM TO BE SOLVED: To provide a blast furnace slag fine powder which causes less bleeding while retaining good fluidity and less autogenous shrinkage and cracking and a cement composition blended with it.SOLUTION: (1) A blast furnace slag fine powder contains (1) a blast slag fine powder subjected to the action of carbon dioxide at 200-700°C is provided. (2) Preferably, the blast furnace slat fine powder has a COcontent of 0.1-5% and has a layer containing a carbonate ingredient in the grain surface. (3) A cement composition comprising cement and the blast furnace slag fine powder (1) or (2) is also provided.