Cement admixture

The invention relates to a cement admixture comprising: A) a comb polymer comprising or consisting of the following substructure units: a) a mole fraction of substructure units of formula (I) S1b) b mole fraction of substructure units of formula (II) S2 wherein M, Ru, Rv, m, R1 are as defined in the application; and B) optionally, an alkanolamine. The cement admixture has a significant improvement effect on cement types such as inferior or inexpensive mineral aggregates, especially in the aspects of grinding aiding effect, water reducing property, expansion degree, flowability and strength. 本发明涉及一种水泥外加剂，其包含：A)梳形聚合物，其包含如下子结构单元或者由如下子结构单元组成：a)a摩尔份数的式(I)的子结构单元S1b)b摩尔份数的式(II)的子结构单元S2其中M、Ru、Rv、m、R1如申请中定义；和B)任选地，烷醇胺。该水泥外加剂特别针对诸如含有劣质或低廉的矿物骨料的水泥类型具有显著的改善作用，特别是在助磨效果、减水性、扩展度、流动性和强度方面。