Multi-component resin system containing - an isocyanate component which comprises at least one aliphatic and/or aromatic polyisocyanate having an average NCO functionality of 2 or more, and - an amine component comprising at least one amine which is reactive to isocyanate groups and has an average NH functionality of 2 or more, with the proviso that the multi-component resin system is free of polyaspartic acid esters, the isocyanate component and/or the amine component comprising at least one filler and at least one rheology additive and the total filling level of a mortar composition produced by mixing the isocyanate component and the amine component being in a range from 30 to 80 wt.%, characterized in that the isocyanate component and/or the amine component contains at least one additive, the additive being - a compound of formula I A n m p (formula I), wherein A represents phosphorous, boron, aluminum, titanium or zirconium, X can be the same or different and represents an alkoxy, aryloxy or acyloxy functional group, L can be the same or different and represents at least one ligand, n represents the valency of A, and p represents an integer from 1 to n, m represents 0 or an integer from 1 to n-1 and n = m+p, or - a siloxane having at least one functional group which is capable of addition reaction to isocyanates, but which has no hydrolyzable groups bonded to a silicon atom. - an isocyanate component which comprises at least one aliphatic and/or aromatic polyisocyanate having an average NCO functionality of 2 or more, and - an amine component comprising at least one amine which is reactive to isocyanate groups and has an average NH functionality of 2 or more, with the proviso that the multi-component resin system is free of polyaspartic acid esters, the isocyanate component and/or the amine component comprising at least one filler and at least one rheology additive and the total filling level of a mortar composition produced by mixing the isocyanate component and the amine component being in a range from 30 to 80 wt.%, characterized in that the isocyanate component and/or the amine component contains at least one additive, the additive being with the proviso that the multi-component resin system is free of polyaspartic acid esters, the isocyanate component and/or the amine component comprising at least one filler and at least one rheology additive and the total filling level of a mortar composition produced by mixing the isocyanate component and the amine component being in a range from 30 to 80 wt.%, characterized in that the isocyanate component and/or the amine component contains at least one additive, the additive being - a compound of formula I A n m p (formula I), wherein A represents phosphorous, boron, aluminum, titanium or zirconium, X can be the same or different and represents an alkoxy, aryloxy or acyloxy functional group, L can be the same or different and represents at least one ligand, n represents the valency of A, and p represents an integer from 1 to n, m represents 0 or an integer from 1 to n-1 and n = m+p, or A represents phosphorous, boron, aluminum, titanium or zirconium, X can be the same or different and represents an alkoxy, aryloxy or acyloxy functional group, L can be the same or different and represents at least one ligand, n represents the valency of A, and p represents an integer from 1 to n, m represents 0 or an integer from 1 to n-1 and n = m+p, - a siloxane having at least one functional group which is capable of addition reaction to isocyanates, but which has no hydrolyzable groups bonded to a silicon atom.