Test series have boon performed on concrete specimens containing bendi
ng cracks. The specimens were subject to fluid penetration. Organic fl
uids (acetone, n-decane, n-heptane) have been used. In a second series
, beams were precracked. The cracks were injected by epoxy or polyuret
hane resin. After 10,000 loading cycles, organic fluids could penetrat
e into the concrete. Results are presented and discussed. Suggestions
for the application in engineering practice are given.