Embedment properties of thermally modified spruce timber with dowel-type fasteners

• This study investigates the effect of thermal modification, ThermoWood Thermo-D treatment versus no treatment, on the embedment properties of Norway spruce timber (Picea abies [L.] Karst.) with dowel-type fasteners. The test specimens were reinforced to prevent splitting of the wood. The influence of density, load direction, test specimen configuration (full hole versus half hole), moisture content, gauge points and calculation method were also evaluated. Thermal modification primarily affected the embedment strength parallel to the grain, which was ∼ 25% higher after thermal modification, mainly due to the change in physical properties because of the treatment, i.e. the lower equilibrium moisture content. The influence of the investigated parameters on embedment properties of thermally modified spruce followed similar trends as for unmodified spruce. It was for example seen that the density–embedment strength relationships still hold after the treatment despite the decrease in density and the increase in embedment strength parallel to the grain. However, after thermal modification, the influence of load direction on embedment strength was ∼30% larger and the influence of calculation method (yield versus ultimate strength) on embedment strength perpendicular to the grain was ∼10% smaller.

Ämnesord

LANTBRUKSVETENSKAPER  -- Lantbruksvetenskap, skogsbruk och fiske -- Trävetenskap (hsv//swe)

AGRICULTURAL SCIENCES  -- Agriculture, Forestry and Fisheries -- Wood Science (hsv//eng)

Nyckelord

ASTM D 5764-97a

Embedment stiffness

Embedment strength

EN 383

Foundation modulus

Full-hole test

Half-hole test

Norway spruce

ThermoWood®

Träteknik

Wood Science and Engineering

Forestry and Wood Technology

Publikations- och innehållstyp

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