WRM 520 is a quick-setting (20min) one-component, concrete-based repair material for concrete. It is a non-shrinkable material with excellent relevance to concrete. After stirring with water, a paste is obtained which can be applied with a scraper or a metal spatula to the surface to be repaired. It consists of cement of special specifications, silicon inerts with high content of silicon and selected granulometry, resins and special improving additives