The present invention relates to polyaspartate mixtures containing a) 5 to 70 equiv. %, based on the total equivalents of aspartate groups, of a cyclic polyaspartate corresponding to the formula wherein X1 represents the residue obtained by removing the amino groups from a cyclic polyamine having a functionality of n, R1 and R2 are identical or different and represent organic groups which are inert to isocyanate groups at a temperature of 100° C. or less, R3 and R4 are identical or different and represent hydrogen or organic groups which are inert towards isocyanate groups at a temperature of 100° C. or less and n is 2 to 4, and b) 30 to 95 equiv. %, based on the total equivalents of aspartate groups, of a polyether polyaspartate corresponding to the formula I wherein X1 represents the residue obtained by removing the amino groups from a polyether polyamine having a functionality of n and a number average molecular weight of less than 600, wherein the amino groups are attached to primary carbon atoms and the ether groups are separated by at least two carbon atoms. The present invention also relates to a process for preparing these polyaspartate mixtures and to the polyureas prepared by reacting the polyaspartate mixtures and optionally other isocyanate-reactive compounds with polyisocyanates.