Automated Strengthening Concept for Reused Concrete Members: Stress Redistribution between Metallic and Non-Metallic Reinforcement

The basis for a high reuse rate for concrete members, automatable strengthening methods are advanta geous. Thin strengthening layers with non-metallic textile mesh can minimise new grey CO₂ emissions.
Applying this method to concrete members under flexural loading, stress redistributions are to be ex pected. This paper combines experimental and analytical methods to characterise redistribution effects between metallic and non-metallic reinforcements with large differences in bond and axial stiffnesses. Using fibre optic sensors, continuous strain measurements were performed and stress redistributions between ribbed steel and textile mesh were identified, which decrease with increasing load. Using an analytical model approach based on the bond–slip differential equation, good agreement with the measured strains was achieved. This forms the basis for a targeted selection of strengthening materials.