The effect of the mobility of the concrete mixture on the air content and frost resistance of concrete

In the technology of building roads, bridges, buildings and structures, concrete mixtures of different mobility are used. It depends on the complexity of the design, equipment and technical requirements. The main requirement for any product or design is high durability. The main index of durability is frost resistance. To increase the frost resistance of concrete, an additional network of air pores is created. This network is formed through the use of airentraining additives and when the concrete mix is mixed. Different quantity of air may enter in concrete mixes of different mobility. But an increase of the quantity of air involved leads to a decrease of concrete performance. Therefore, it is necessary to know the volume of air bubbles and how they change the properties of concrete. The work shows how the mobility of concrete mixtures affects on the amount of air involved. The results of studies of frost resistance of concrete made from mixtures of different mobility are presented.