Estmating Extreme Thermal Actions in Concrete Structures

Författare

Oskar Larsson

Summary, in English

The surrounding climate gives temperature variations in both time and space for concrete structures. Due to external and internal restraints thermal strains and stresses may develop in the structure and these stresses can contribute to cracking. This will affect the performance of the structure. To predict the dynamic thermal conditions in concrete structures a finite element model has been developed. Field temperature measurements in a concrete slab placed outdoors and measurements of climatic data are used for the validation of the model. A validation with input data from the Swedish Meteorological and Hydrological Institute has also been performed to be able to use the model for simulations over long time periods. The results show that the model can describe the effects from different climatic factors in extreme situations with good accuracy based on data from meteorological stations. It is important to use climatic data with a good resolution, since variations during the day can give unfavorable situations. The analyses with longer time periods show that the values for linear temperature gradients in the Eurocode could be underestimated for Swedish conditions. There is also a tendency towards geographical differences which has not been included before. An asphalt paving layer increases positive linear temperature gradients while they decrease with a concrete paving.

Avdelning/ar