Grouting of cracks and voids in waterproof concrete Water impermeability gives concrete special functionality as a building material in addition to its proper-ties of strength, formability and economy. Its use for structures without any additional external water-proofing measures demands particularly meticulous design and construction. The limits of its capability also have to be observed. The construction industry can achieve the avoidance or limitation of the expected crack formation through detailing, concrete technological or constructional measures. Nonetheless, tension cracks re-main unavoidable. Grouting technologies can recreate the intended state of water impermeability. In building practice, some grouting is inherently necessary in reinforced concrete construction, particu-larly to waterproof concrete. The successful application of grouting system demands understanding of the basics of concrete technology on the one hand, and understanding of water transport in concrete and grouting technology on the other. The practicality of grouting unavoidable cracks was already investigated relatively early [1]. Then addi-tional research results were published about water transport on concrete [2]. Further work was devoted to the self-healing of cracks in concrete [3] and the technical state of grouting of cracks and voids in concrete elements [4]. These offer the foundation for the successful application of waterproof concrete in combination with grouting measures.
