Influence of weak parts in concrete structure on resistance of concrete to water penetration

摘要

The diploma thesis deals with the resistance of three different concretes against penetration of water under pressure. Water-binder ratio of first concrete mix was 0.55 and of second and third mix it was 0.40. The concrete mixes were made using crushed limestone aggregate, tap water and cement CEM II/A-M (LL-S) 42,5R. The second and the third mix incorporated polycarboxylate type of superplasticizer and in the third mix cement was partially replaced by fly ash. On fresh concrete mixes different consistency tests were carried out and air content was determined, and on hardened concrete mixes compressive and splitting tensile tests were carried out. In case of compressive strength the influence of curing and the type of mould material were tested as well. At the end the influence of weak parts in the concrete structure on the resistance against penetration of water under pressure were studied. The studied weak parts were honeycombs, bug holes and cold joints.