Reduction of wood consumption for glulam arch by its strengthening

This paper focuses on possibilities to reduce wood consumption for 11 glulam arches with rise-span ratio selected from 1/7 to 1/2. The most loaded sections of each arch are strengthened in 7 different ways: by attaching non-prestressed glass fiber-reinforced-polymer (GFRP) and carbon-fiber-reinforced polymer (CFRP) laminates, by attaching prestressed GFRP and CFRP laminates, with steel reinforcement bars and by attaching prestressed GFRP and CFRP laminates to the reinforced arch. Efficiency rates of various strengthening types are compared and also the use of design resistance is estimated. The span of arches is assumed constant – 42 m. The arches are subjected to snow load s0=1.5 kN/m2 and wind load w0=0.23 kN/m2. It is verified that compressive, bending, shear and tensile stress in wood fibres does not exceed design strength value as well as stress in FRP laminate and steel reinforcement bars does not exceed their design resistances and the anchorage of reinforcement is provided. Analytical calculations confirmed that maximum cross-section reduction can be achieved by attaching prestressed CFRP laminates to reinforced arch resulting in wood consumption reduction up to 31%.