Aging of some GFRP-concrete joints under external pressure

Aging of some GFRP-concrete joints under external pressure, Silva, M. A. G., Biscaia H. C., and Chastre C. , AIS2017 - 6th Asia-Pacific Conference on FRP in Structures, July 19-21 , Singapore, (2017) copy at

Date Presented:

July 19-21


Compressive stresses created by lateral external pressure on laminates are an important factor on success of the use of mechanical anchorage of externally bonded reinforcement (EBR). A program of double shear tests with imposed normal stresses on GFRP plates bonded to a concrete surface and a bond-slip model are described. Results generated numerically are summarized and used as reference values against those obtained after accelerated aging by freeze-thaw cycles, and temperature cycles of the same amplitude but range closer to the glass vitreous temperature. Numerical modelling showed that the bonded length is fully stressed prior to failure. Increasing lateral pressure led to a larger maximum bond stress and strength at the interface. Cohesion, fracture energy and internal friction angle changes are calculated and used to analyze the effects of the aforementioned cycles on the expected behaviour of the GFRP-concrete joints, namely at the interface.


REFERENCES[1] Biscaia, H.C., Chastre, C. and Silva, M.A.G. (2012). “Double shear tests to evaluate the bond strength between GFRP/concrete elements”, Composite Structures, 94(2), 681-694.[2] Biscaia, H.C., Chastre, C. and Viegas, A. (2015). “A new discrete method to model FRP-to-parent material bonded joints”, Composite Structures. 121, 280-295.[3] Biscaia, H.C., Chastre, C. and Silva, M.A.G. (2015), “Bond-slip model for FRP-to-concrete bonded joints under external compression”, Composites part B: Engineering, 80, 246-259.[4] Biscaia, H.C., Silva, M.A.G. and Chastre, C. (2015). “Influence of external compressive stresses on the performance of GFRP-to-concrete interfaces subjected to aggressive environments: An experimental analysis”, Journal of Composites for Construction, 04015044.[5] Büyüköztürk, O. (Coordinator). (2004). “Failure Behavior of FRP Bonded Concrete Affected by Interface Fracture. Part I”. Report NSF Grant Number CMS-0010126.[6] Silva, M.A.G. and Biscaia, H.C. (2010). “Effects of exposure to saline humidity on bond between GFRP and concrete”, Composite Structures, 93(1), 216-224.[7] Silva, M.A.G., Biscaia, H.C. and Marreiros, R. (2013). “Bond-slip on CFRP/GFRP-to-concrete joints subjected to moisture, salt fog and temperature cycles”, Composites Part B: Engineering, 55, 374-385.