Neue Holzbau AG has over 10 years of experience in manufacturing Glulam made of hardwood. Apart from elements in ash and beech, also elements in oak and locust have been produced. Hardwood shows strength values that exceed the more frequently used construction wood made of pinewood. Especially its crush resistance and tensile strength, but also its fibre-parallel push- and pull stability considerably exceed the quality of pinewood. Furthermore, the significantly higher efficiency of the fastener in the hardwood plays an important role.
Hardwood, which is a glued-laminated element, is the natural high performance material for future timber engineering. Beams of classification GL48 are made possible due to the application of quality-tested boards made of hardwood (strength class 40, ash and beech). 48 defines the value of the characteristic bending strength in N/mm2. Glulam from spruce is mostly used in strength class GL24, i.e. half the strength. Naturally, the significantly higher strength is accompanied by higher demands on production and quality management. In order to ensure highest quality of the construction elements, laminations and finger joints are tested on tensile testing facilities before and during production.
|characteristic values for LH-BSH|
(values in [N/mm2], valid for HF 12%)
|flexural strength||ƒm,d||26.5 N/mm2||32 N/mm2||24 N/mm2|
|tensile strength | | to the fiber direction||ƒt,0,d||20 N/mm2||22 N/mm2||16 N/mm2|
|tensile strength ⊥ to the fiber direction||ƒt,90,d||0.25 N/mm2||0.25 N/mm2||0.15 N/mm2|
|compressive strength || to the fiber direction||ƒf,d,d||22 N/mm2||25 N/mm2||18 N/mm2|
|compressive strength ⊥ to the fiber direction|
|- general||4.5 N/mm2||5 N/mm2||2.2 N/mm2|
|- mit Vorholz||ƒc,90,d||6.3 N/mm2||7 N/mm2||3.0 N/mm2|
|- end support||5 N/mm2||6 N/mm2||3.0 N/mm2|
|shear strength||ƒv,d||3 N/mm2||3 N/mm2||1.8 N/mm2|
|modulus of elasticity || to the fiber direction||E0,mean||14 kN/mm2||15 kN/mm2||14 kN/mm2|
|modulus of elasticity ⊥ to the fiber direction||E90, mean||1 kN/mm2||1 kN/mm2||0.4 kN/mm2|
|shear modulus||Gmean||1 kN/mm2||1 kN/mm2||0.4 kN/mm2|