Determination of in-situ concrete compressive strength under consideration of rearrangement effects

Abstract

For the design of existing structures the concrete compressive strength and the derived mechanical parameters are of central importance. Due to safety reasons the compressive strength of existing concrete is usually set comparatively low and thus underestimated. The reasons for this are the limited numbers and the large scatter of material properties of the drill cores, which are the basis for the experimental determination of the compressive strength. In contrast to experimental tests the load in structural components of buildings usually is transferred over the area with higher stiffness and consequently with higher compressive strength. Therefore, existing strength variations within a component only play a subordinate role due to rearrangement effects. This paper deals with the experimental and numerical analysis of such rearrangement effects in order to determine the concrete compressive strength of existing structures more realistic and lay a basis for a economical design. By considering these rearrangement effects more realistic during the design of existing concrete structures, a higher number of existing buildings can be maintained without structural measures. The preservation of existing structures is not only decisive from an economic, sustainable and resource-saving point of view, but also represents an added value for cultural and social aspects.