Short- and long-term deflections of RC slabs strengthened with CFRP systems under sustained loading and different environmental conditioning
Year: 2025
Type: article
Abstract: This study investigates the combined effects of sustained loading and environmental conditioning on the short- and long-term mid-span deflection behavior of reinforced concrete (RC) slabs strengthened using different CFRP-based techniques: (i) Externally Bonded Reinforcement (EBR), (ii) Near-Surface Mounted (NSM), (iii) EBR with prestressing via mechanical anchorage (EBR-MA), and (iv) EBR with prestressing via gradient anchorage (EBR-GA). Over a period of up to six years, each one of 24 studied slabs was subjected to a sustained load equivalent to approximately 40% of its ultimate capacity and exposed to one of following 6 environmental conditions: (i,ii) two controlled laboratory settings - 20 °C and 55% relative humidity in a climatic chamber, and full immersion in tap water at 20 °C in tanks; (iii to vi) four outdoor exposure sites across Portugal, each characterized by distinct humidity levels, temperature variations, freeze-thaw cycles, and UV radiation exposure. Instantaneous and long-term mid-span deflections were recorded and compared with the adopted predictive models. The results demonstrate that both the axial stiffness of the CFRP and the selected strengthening technique significantly influence deflection magnitude. Furthermore, the observed deflections closely align with the predicted values, and the proposed time-dependent factor curves offer a valuable tool towards establishing simplified predictive models.
Source: Engineering Structures
Institution: University of Minho
Language: English
Subfield: Building and Construction
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,620
OpenAlex ID: W4415890418