Water penetration into micro-cracks in reinforced concrete

Cracks play a decisive role for durability and service life of reinforced concrete structures. In the contribution very fine micro-cracks, which are usually neglected in durability design were induced mechanically into steel reinforced mortar and concrete elements. It turned out that even finest micro-cracks are immediately water filled whenever the surface comes in contact with liquid water. lt can be concluded that micro-cracks have also to be taken into consideration in any realistic service life design. The penetration depth of micro-cracks in concrete plays a decisive role for service life. The role of micro-cracks for durability can be significantly reduced by water repellent treatment of the cracked surface. Further investigations will tell us to which degree and in which environment self-healing may reduce the influence of micro-cracks for durability of reinforced concrete. (A)