Dispergeringsmiddel for höy-ström eller selvkompakterende betong

摘要

Cement dispersing agents for self compacting concrete of high flowability, comprising a water-soluble N-vinyl copolymer, prepared by copolymerizing (a) an N-vinyl lactame or N-vinyl-amide with (b) a polyethylene glycol ester of maleic acid containing 6 to 300 moles of oxyethylene groups per molecule and (c) at least one monomer selected from among unsaturated dicarboxylic acids and (d) methallylsulfonic acid. When an aqueous solution of this copolymer is used as an admixture to freshly prepared concrete of even extremely low water-to-cement ratio, high fluidity, low decrease in flowability with progression of time and lack of segregation over time is attained.