New generations of glulam beams made of French native hardwoods and softwoods

Transcription

1 New generations of glulam beams made of French native hardwoods and softwoods New industrial applications in the field of Engineered Wood based Products Frédéric SIMON Ronny BREDESEN Per LIND FCBA Institut technologique Forêt Cellulose Bois construction Ameublement

2 Innovation in TIMBER Construction «Innovation is not revolution» in Timber Construction «The right wood for the right use» Compliance with regulations Promoting the French native wood resource In adequation with the economical situation Suitable for the French wood industry (mainly SME s) Ensure users safety Enhance enterprises competitiveness Facilitate trade 2 FCBA

3 Glulam barrels for wine ageing Use of native ash and high quality tasty oak Small production transferred to Spain, fighting against very traditional and challenging market FCBA

4 Very interesting logs Lab results sawn timber Defects removal Finger jointing Transferred to the Plant scale Drying CUAP approved For Maritime pine Valuable for green wood finger jointing ETE on the way New research on oak FCBA

5 Innovative glulam beams made of Maritime pine: feasability study Higher shear strength for bonded joints Higher beam shear strength than required by EC5 (3.3 versus 2.7 MPa) Very promising results for 4-point bending strength, but lower than GL24 requirements Flanges finger jointing quality Deviation in bending strength FCBA

6 2 new projects in the field of glulam beams made with French native woods French K-beams project: fiabilization study to: Improve the flanges finger jointing quality Produce numerous maritime pine beams to get reliable characterizing values After Klaus, in January 2009, 5 years of pine production laying down in forests Oak glulam beams for load bearing timber structures How to measure the real strength of visually graded wood Adhesive systems approval for oak compatibility Improving the finger jointing process Production and testing of prototype beams In a very difficult economical context for hardwoods in Europe FCBA

7 French K-beams Project: fiabilization study 2c EPI adhesive system FCBA 7

8 French K-beams Project: Step 1 results Bending strength of finger jointed lamellae NF EN standard NF EN 1194 standard NF EN 385 standard Finger jointed Maritime Pine samples Failure mode Samples number k s = Characteristical flatwise bending strength (MPa) Equivalent strength class Corrected* Charac. Flatwise bending strength (MPa) Equivalent strength class Full sampling all 35 1,86 32,4 C27 25,9 C ,88 34,1 C30 27,3 C27 C30 graded wood in the profile 16 1,98 37,3 C30 29,8 C27 C18 graded wood 12 2,06 36,2 C30 29,0 C27 Requirements: NF EN 1194:1999 f m,j,k >8+1,4 f t,0,l,k with f t,0,l,k : Lamellae characteristic tensile strength f m,j,k : FJ lamellae characteristic flatwise bending strength * depending on the profile dimensions (k f =1,25) Tensile strength of finger jointed lamellae NF EN standard NF EN 1194 standard Finger jointed Maritime Pine samples Full sampling Failure mode Samples number k s = Characteristic tensile strength (MPa) Equivalent strength class in the 12 2,06 23,7 C30 profile Requirements: NF EN 1194:1999 f t,j,k >5+ f t,0,l,k f t,0,l,k : Lamellae characteristic tensile strength f t,j,k : FJ lamellae characteristic tensile strength FCBA 8

9 French K-beams Project: Step 2 results Bending strength of finger jointed lamellae From small-scale sampling to industrial production NF EN standard NF EN 1194 standard NF EN 385 standard Finger jointed Maritime Pine samples Failure mode Samples number k s = Characteristical flatwise bending strength (MPa) Equivalent strength class Corrected* Charac. Flatwise bending strength (MPa) Equivalent strength class Full sampling all 31 1,87 36,4 C30 29,1 C27 in the 25 1,90 40,6 C35 32,5 C30 C30 graded wood profile 16 1,94 41,1 C35 32,8 C30 Requirements: NF EN 1194:1999 f m,j,k >8+1,4 f t,0,l,k with f t,0,l,k : Lamellae characteristic tensile strength f m,j,k : FJ lamellae characteristic flatwise bending strength * depending on the profile dimensions (k f =1,25) More than 400 ml Delivered to Norway For beams production FCBA

10 French K-beams Project: Step 3 results Bending strength of 52 beams made with Pine Only one configuration: 10 inside thin lamellae, 2 flanges FCBA

11 French K-beams Project: fiabilization study Char. Density = 571 kg/m 3 GL24 requirements fulfilled: fv,k = 24 MPa, E = MPa FCBA 11

12 Oak glulam beams Project: Phase 1 How to link visual grading to mechanical grading for oak from the partner s sawmill Phase 2 Compatibility tests for oak bonding for load bearing timber structures Phase 3 Handling different oak qualities in glulam plant: lamellae finger jointing before face gluing : prototypes beams production according to EN 386 standard Phase 4 Mechanical testing of the whole production FCBA 12

13 Oak glulam beams Project: Visual grading / Mechanical grading 2 visual qualities: QF2 & QF4 2 cross sections: 27x175 mm & 27x230 mm More than 50 samples tested per config. Sawmill Visual grading QF2 QF4 D30 D24 FCBA Lab Mech. grading EN 975 Better than NF B52001 standard FCBA Lab visual grading QF2 QF3 QF4 D35 D30 D24 FCBA Lab Mech. grading FCBA 13

14 Oak glulam beams Project: compatibility for structural bonding Tested according to EN std Drying cycles not adapted to hardwood species => collapse Difficult to identify real delaminations versus wood cells failures MUF adhesive system selected to get clear joints FCBA 14

15 Oak glulam beams Project: beams production Overall production 2250 meters of 210 mm wide finger jointed lamellae 1200 meters of 170 mm wide finger jointed lamellae 132 meters long of beams (210x300 mm) 121 meters long of beams (170x150 mm) FCBA 15

16 210 mm wide lamellae Production 170 mm wide lamellae Test 160 mm wide lamellae Oak glulam beams Project: finger joints testing Bending strength of finger jointed lamellae From samples properties to industrial production NF EN standard NF EN 1194 standard NF EN 385 standard Finger jointed Oak samples Failure mode Samples number k s = Characteristical flatwise bending strength (MPa) Equivalent strength class Corrected* Charac. Flatwise bending strength (MPa) Equivalent strength class Full sampling all (mainly A1) 23 1,91 41,6 D40 33,3 D30 Full sampling all 36 1,85 39,6 D35 31,7 D30 Failure in the profile A1 26 1,89 46,8 D45 37,4 D35 A2/A3 10 2,10 29,8 D24 24,0 D24 Full sampling all 31 1,87 44,1 D40 35,3 D35 Failure in the profile A1 18 1,95 47,6 D45 38,1 D35 A2/A3 13 2,03 40,4 D35 32,3 D30 Requirements: NF EN 1194:1999 f m,j,k >8+1,4 f t,0,l,k with f t,0,l,k : Lamellae characteristic tensile strength f m,j,k : FJ lamellae characteristic flatwise bending strength * depending on the profile dimensions (k f =1,25) FCBA 16

17 Oak glulam beams Project: beams testing 4 point Bending strength of beams 3 point Bending strength of beams FCBA 17

18 Oak glulam beams Project: beams testing 4 point Bending strength of beams Char. Density = 721 kg/m 3 Beams cross sections Number of tested beams Wood quality (outside/inside lamellae) 205 x 300 mm² 21 QF2 / QF4 Failure mode Finger Joint Average MOE (MPa) Corrected bending strength f m * (MPa) Average Std deviation COV (%) Characteristic bending strength f m,k ** (MPa) Characteristic bending strength f m,k *** (h=600 mm) (MPa) ,1 4,3 10,2% 34,4 32,2 16 all ,2 8,2 16,7% 35,6 32,4 165 x 150 mm² 9 QF2 / QF4 FJ ,2 3,5 7,9% 37,2 33,8 7 wood outside profile ,7 8,0 14,3% 39,6 36,0 5 QF ,4 3,5 7,5% 38,4 34,9 all 4 QF ,6 3,3 7,2% 37,2 33,8 Nota 1 : * Correction considering the wood MC during testing and the characteristical density of the reference wood species Nota 2 : ** Characteristic value calculated according to the EN standard Nota 3 : *** Correction performed according to the requirements of EN standard (Eurocode 5) taking into account 600 mm height GL28 requirements : fv,k = 28 Mpa E = MPa FCBA 18

19 Oak glulam beams Project: beams testing 3 point Bending strength of beams according to EN 408 std 3 point bending tests on 165 x 150 mm² beams cross section Tested beams number k s = EN standard: Charact. Flatwise bending strength (MPa) corrected versus tested oak batch: r k =724 kg/m 3 Full sampling 14 2,01 6,9 QF4 lamellae 5 2,46 6,4 QF2 lamellae 4 2,81 6,9 2 QF2 outside lamellae / 5 QF4 inside lamellae 5 2,46 6,7 Requirements: NF EN 1194:1999 f v,k : Characteristical Shear strength GL24h: f v,k =2,7 MPa GL28h: f v,k =3,2 MPa GL32h: f v,k =3,8 MPa GL36h: f v,k =4,3 MPa Shear strength of glue lines according to EN 392 std Average WF > 90 % EN 386 requirements on average values: fv>11 MPa / 45 % WF FCBA 19

20 Conclusions how to improve the use of native wood resource for timber construction by the way of EWP => could be the right direction the gluing step is very important => choice of the adhesive system and working properties the right wood for the right use for technical & economical reasons standards have to take into account new wood species and maybe new process => long time, many tests same projects are currently running at FCBA for beech and chestnut and also in other Institutes in Europe FCBA 20

21 THANK YOU FOR YOUR ATTENTION / Acknowledgments: Partners: Technical Partners for production: DRAAF Aquitaine for fundings FCBA 21