The shear and flexural behavior of cold-formed steel composite I and U beams

Recycling and re-usability of waste materials are of great importance in terms of ecological order. Furthermore, cold-formed steel has recently drawn considerable attention. The objective of the present study was to investigate the bending and shear behavior of the composite formed by pouring waste polymer into the cold-formed I and U prole melds after homogenous pulping. The best results for shear and bending strengths were obtained using melted polypropylene (PP). The enhanced adherence between the steel and molted PP increased both shear and bending capacity. Moreover, it was reinforced by Carbon Fiber Reinforced Polymer (CFRP) and Glass Fiber Reinforced Polymer (GFRP) bars to increase the bending and shear behavior of I and U proles filled with melted waste polymer. Changing the cross-sectional area in I and U beams under the bending moment had a considerable effect on the load at yielding, ultimate strength, displacement values corresponding to these loads, ductility, and energy dissipation capacity. Addition of CFRP to I beams could also significantly increase displacement capacity in free end regions under the shear force. Addition of GFRP bars, rather than CFRP bars, with a higher elongation capacity in I and U beams caused ductile behavior.