Major construction projects such as the Great Belt link, the Øresund link and the Malmø Citytunnel pose great demands on the concrete durability. Significant expenses can be avoided by carrying out an optimization of the casting and curing process.
An in-depth optimization of the casting process may be carried out based on temperature stress calculations on the structure. Such calculations require detailed knowledge of the early age properties of the concrete, e.g. the creep and shrinkage properties.
Monitoring the early age creep and shrinkage behaviour is a complicated test comprising measurement of deformations of a few microns and strict control of the temperature regime and it can only be executed in a controlled laboratory environment.
Many modern high performance concretes have a short setting time and thus, do not leave time for transporting the fresh concrete to a laboratory for casting of test samples. Furthermore, as the measurements have to start as early as 12 maturity hours after casting, the samples can not be transported without being damaged.
Consequently, the determination of the early age concrete properties often requires these to be measured on-site.