XFEM Modelling and Experimental Observations of Foam Concrete Beam Externally-Bonded with KFRP Sheet

Abstract

This paper investigates the effect of KFRP composite sheets as a strengthening material in improving the load-carrying resistance of lightweight foam concrete beams using a FEA modelling framework. The study employed three parametric strengthening schemes (i.e., KFRP length, woven architecture types and KFRP thickness). Twenty-seven beam specimens were tested, and respective failure modes and ultimate load at failure were discussed. All the strengthened beam specimens failed mostly in shear mode and, to a lesser extent, in FRP fracture. Despite the absence of de-bonding failure, improvement of strengthening using KFRP sheet technique was exhibited. Later, Extended Finite Element Method (XFEM) Modelling was incorporated following failure mode exhibited. Strength predictions incorporating the traction-separation relationship using XFEM techniques. Validation work with experimental datasets showed good agreements with average discrepancies of less than 10%. The numerical approach can be used as a strength prediction tool in concrete beams with externally bonded FRPs.

Keywords:
Foam concrete; Beam strengthening; FRP rupture; kenaf fiber composite; FEA Modelling

Graphical Abstract