Application of photoelastic coating technique in tests of solid wooden beams reinforced with CFRP strips

The paper presents selected results of tests carried out on hundred year old joists strengthened with carbon fibre reinforced polymers (CFRP). Besides the conventional electric-resistance extensometers (ERSG), the photoelastic coating technique (PCT) was used to measure strains in the reinforced (bonded) cross sections. No such attempt to apply PCT has been described in the literature before. The technique requires further studies to verify agreement between its results and the ones obtained by conventional measuring techniques.