Effect of sustained loading and environmental conditions on the creep behavior of an epoxy adhesive for concrete structures strengthened with CFRP laminates

CFRP-laminates-amade-emara

Effect of sustained loading and environmental conditions on the creep behavior of an epoxy adhesive for concrete structures strengthened with CFRP laminates

Creep happens when a loaded material suffers plastic deformation increase over time. It is heavily influenced by temperature and humidity. The study Effect of sustained loading and environmental conditions on the creep behavior of an epoxy adhesive for concrete structures strengthened with CFRP laminates by M. Emara et al. (in Composites: Part B) explores this phenomenon for an epoxy adhesive used to reinforce concrete structures. An experimental campaign has been done in order to characterize the material, specially its glass transition temperature, which has been avered to be a range more than a definite point. After, the creep behaviour has been tested in a climate chamber under different load intensities, temperatures and humidities. Results confirmed the great importance of temperature, even above humidity, and that those are more remarcable under relatively high loads.

 

Paper information

Title Effect of sustained loading and environmental conditions on the creep behavior of an epoxy adhesive for concrete structures strengthened with CFRP laminates
Authors: M. Emara, L. Torres, M. Baena, C. Barris, M. Moawad
Journal, Volume, Page, Year: Composites part B: Engineering, Vol. 129, pp. 88-96, 15 Nov 2017
DOI:

https://doi.org/10.1016/j.compositesb.2017.07.026

 

Highlights

  • Increasing temperature and humidity caused a rapid increase in the creep behavior. Temperature, compared to that of humidity, showed a greater effect on the instantaneous strain, creep coefficient and time to failure.
  • The adhesive tested showed a linear viscoelastic creep behavior up to a sustained loading level equal to 60% under 20°C and humidity level equal to 55%. This level of load for linear creep behavior started to decrease when the environmental conditions were changed to more extreme conditions.
  • Increasing both temperature and humidity resulted in shorter times to failure for all specimens due to the rapid degradation in the adhesive’s strength and the stiffness.
  • The epoxy adhesive’s glass transition temperature cannot be considered as a unique temperature, but rather it should be considered as a range of temperatures.

 

Project and Finding

  • Relevant projects: BIA2013-46944-C2-2-P, MC-ITN2013-607851
  • Funding institutions: Spanish Government (Ministerio de Economía y Competividad). The European Network for Durable Reinforcement and Rehabilitation Solutions (endure), a Marie Sklodowska Curie Initial Training Network.