A simplified design of a concrete sandwich structure containing a reinforcing rib

This article presents the use of a strut and tie analogy for modelling the behaviour of a concrete sandwich structure, which is formed by thin outer concrete layers made of high-performance concrete and reinforcing ribs. The beams transmitting shear are made of a rigid material with low thermal conductivity (Purenit) in combination with a carbon fibre reinforced polymer. The purpose of these ribs is to ensure reliable shear interaction of the outer concrete layers regardless of the thermal insulation of the sandwich structure. A simplified model using the truss analogy in the Scia Engineer software was used for the design of this structure. Furthermore, this design was verified experimentally on a section of the sandwich panel where the feasibility and functionality were tested by a four-point bending test. Finally, the theoretical values from the model were compared with the experimental results. This also includes a simple evaluation of whether this simplified modelling of the structure’s behaviour is appropriate. The paper contains a summary of the conditions that could have affected the results.