Production of mass concrete

Fresh concrete Limiting the temperature of the fresh concrete is a simple way of Maximum component temperature to be limited. In the case of massive components, a limitation to the following has proven to be effective in practice maximum 25°C proven. This has also found its way into specific sets of rules. A limit below this can also make technical sense. For example, the average annual ambient temperature or, in tunnel construction, the rock temperature is often used as a rule of thumb. Hardened concrete The maximum temperature in the component core of the cast concrete can be determined by calculation and, in addition to factors such as component thickness and cement type, is essentially dependent on the fresh concrete temperature. The maximum permissible concrete temperature indirectly determines the fresh concrete temperature. In order to avoid stress cracks, a maximum temperature difference of 20K between the core and the edge of the component is generally assumed. However, if expansions in the component are completely hindered, temperature differences of approx. 10K already lead to cracks in the concrete.

Especially at high outside temperatures, the required fresh concrete temperatures can only be achieved by appropriate cooling or heating measures. KTI is a specialist in this field and has Many years of experience for cooling and heating of mass concrete: Our recommended measures for maintaining fresh concrete temperature are:

• Protected storage of the aggregates to avoid freezing or heating up
• Active cooling or heating of the aggregates
• Cooling or heating the addition water
• Addition of plate ice or flake ice at high ambient temperatures
• Ensure short transport routes for the concrete
• Pipe internal cooling, so-called post-cooling, in the concrete component with cold water