| 摘要 |
PURPOSE: To improve the quick-setting property of concrete while keeping the fluidity in the pneumatical application of the concrete. CONSTITUTION: This concrete is incorporated with one or more kinds of admixtures selected from (A) a condensate/salt of an aminoarylsulfonic acid, a phenol derivative and formaldehyde, (B) a condensate/salt of an aminoarylsulfonic acid, a melamine sulfonic acid derivative and formaldehyde, (C) a sulfonic acid group-containing aliphatic diene (co)polymer/salt containing an aliphatic diene and optionally other monomers copolymerizable therewith as constituent components and having a pendant double bond content of 20-60% in the diene part and a weight-average molecular weight of 1,000-200,000 and (D) a polystyrenesulfonic acid, etc., partially alkylated with a 2-12C alkyl group at an average alkylation ratio of 0.01-0.03mol based on the benzene ring and having a weight-average molecular weight of 5,000-50,000. |
