Kütle betonu ve uygulamaları

Today, both especially the foundations of high-rise buildings are cast thick in large mass and the densely reinforced concrete that is over C35/45, cement rich, and high quality is used on the foundations. As is known, due to the hydration heat of cement in the mass concretes, the cracks caused by the extreme temperature differences within the concrete and between the concrete and environment may cause serious problems. Therefore, since it will be in contact with the underground waters containing harmful substances, chemicals, etc.; especially in the thick foundation concrete castings, the dosage and hydration heat of the cement used, the thickness of the concrete, protection measures, staged casting, the efforts for pre-cooling and post-cooling of the concrete are important. In this study, the internal temperatures of concrete and the environment temperatures were measured using the thermocouples placed at certain points before the concrete casting in different construction sites. In these measurements, excessive emphasis was put on the waiting times and the measures to be taken to prevent the difference between the internal temperature (hydration) of the concrete and the external temperature from exceeding 20 C. For this purpose, the cement types with different cement dosages and mineral additives were used in different foundation thicknesses. Since the temperature increase in the concrete and minimizing the difference between the environment and the concrete surface were especially of great importance in preventing the concrete cracking; it was observed that the temperature difference was reduced and, by doing so, the concrete was cast without any crack through some measures such as reducing the casting thickness, casting the concrete in one time and covering the surface of the concrete with the materials such as nylon and styrofoam etc., and casting the concrete in several stages and waiting for the concrete to cool down. Keywords: Mass Concrete And Its Application