Flexural behavior of wood beams strengthened with HFRP

In order to increase the strengthening efficiency, a proposal for strengthening wood beams with hybrid fiber reinforced polymer (HFRP) is made. Carbon fiber (CF), glass fiber (GF) and high-strength glass fiber (SGF) were chosen as strengthening materials. CF strengthening beams, SCF strengthening beams, hybrid CF/GF strengthening beams, and hybrid CF/SGF strengthening beams were produced. A flexural experimental study including 12 strengthened beams and 3 control wood beams was carried out. The failure modes and failure mechanisms of the FRP and HFRP strengthened beams were investigated. The load–displacement characteristics, ultimate moment capacity and ductility of the different strengthened beams were discussed. The test results show that, compared with singly CF or SGF strengthening, HFRP strengthening may significantly increase the ductility of the strengthened wood beams under the premise of increasing moment capacity greatly at a lower cost. A calculation model for predicting ultimate moment capacity of wood beams strengthened with HFRP was put forward. The calculation results show a basic agreement with the tested values.

► A proposal for strengthening wood beams with hybrid fiber reinforced polymer (HFRP) is made.
► A comparative experimental study for determining the flexural behavior of HFRP strengthening wood beams was carried out.
► Compared to the other strengthening schemes, hybrid CF/SGF strengthening can obtain a much better ductility.
► The fiber material cost of hybrid CF/SGF strengthened beams is only 50% of that of CF strengthened beams.