Flexural behaviors of GFRP-wood sandwich beams with recycled wood formwork cores

The escalating consumption of wood products has inevitably led to a rapid accumulation of waste wood, of which a large amount has been landfilled. An innovative concept has been therefore proposed to repurposes waste wood formwork as the core material of Glass Fiber Reinforced Polymer (GFRP)-wood sandwich beams. A series of four-point bending tests were conducted on these sandwich beams, with the thicknesses and orientations of strengthening GFRP layers as the main test parameters examined. The test findings indicated that the GFRP-waste wood sandwich beams failed in either buckling of compression zone or rupture of GFRP covering. In addition, the increase in the number of GFRP layer resulted in a significant increase in the both bending stiffness and flexural strength, and the beams strengthened with three-layer GFRP sheets exhibited the bending stiffness and flexural strength up to respectively 4.7 and 6.5 times greater than those without such GFRP strengthening. The analytical and numerical predictions of flexural properties of sandwich beams are in a good agreement with the test results, thereby validating the accuracy of the models employed in the present study.