ABSTRACT
This situation was the starting point of a research activity at several places. Experi ments were performed on different concrete compositions, with addition, especially treated and cured, fluids were classified and their transport behaviour verified. At on ce, many data were available. Simultaneously, theories from other fields like chemophysics, geophysics, building physics were checked and models were derived which describe the fluid flow in concrete taking account of the main parameters. It became obvious that the capillary pressure is the paramount driving force for the penetration of a fluid into concrete. Opposite to granular soil, concrete has tiny pores ranging from some nanometers to several micrometers in diameter generating a large capillary pres sure. An external hydraulic pressure can be neglected in most cases.
