Analysis of composite T beam composed of timber, concrete and carbon strip

Transcription

1 WSEAS TRANSACTONS on APPLED and THEORETCAL ECHANCS Analysis o omposie T beam omposed o imber onree and arbon srip ATJAŽ TAJNK PETER DOBRLA ROSLAV PREROV Fauly o ivil engineering Universiy o aribor Smeanova ulia 17 S 000 aribor SLOVENA majaz.ajni@uni-mb.si hp:// Absra: This paper provides a mahemaial el and numerial example o omposie T-seion omposed o a onree plae and a imber beam srenghened a he boom ension side wih a arbon ibre-reinored polymer (CFRP) srip. Analysis is provided in aordane wih he European sandards or imber seel and onree sruures. The ensile srengh o he arbon srip as well as he ompressive srengh o he onree plae are higher han he bending srengh o he imber beam hereore i is onvenien o use suh omposiion o maerial o gain a higher load bearing apaiy. has been shown ha he inlusion o CFRP srip reinoremen on he inrease o load arrying and bending siness apaiy was no as high as expeed. On he oher hand we realized he imporane o variey o maerial grade and geomerial properies ombinaions beween sub-omponens whih an signiianly improve load bearing apaiy and siness o omposed beam. Furhermore he CFRP srip onribuion o he bending resisane and siness o he elemen is presened as a union o he asener spaing inervals beween onree plae and imber beam. Key-Words: Composie sruures Timber sruures Carbon srip Load bearing apaiy odelling 1 nroduion Nowadays he signiiane o he proeion and reonsruion o old and hisori buildings is inreasing in ern planning. Thereore an eiien ype o loor sysem whih onsiss o imber members in he ensile zone a hin onree layer in ompression zone and he onneion beween imber and onree has drawn aenion o he expers in he ield o ivil engineering. The resuls o suh reonsruion-srenghening proedure or new omposie onsruion (ompared o imber loors) are inrease o siness load bearing apaiy improved sound insulaion and beer ire resisane. Fig. 1: odel o reonsruion o imber loor The sruural behaviour o imber-onree omposie members is governed by he shear onneion beween hem. Whaever sysem o aseners is used in omposed seion seel ibre reinored onree (SFRC) shows muh beer haraerisis hen lassi reinored onree. Holshemaher Kloz and Weibe (00) demonsraed heir experimenal sudies using SFRC [9]. Tha soluion maes he reduion o slab hiness possible under lexure he iniial ra load an be inrease. When he irs ra ours he released ores an be ranserred over he ra and hereore brile ailure is prevened. When applying SFRC he experimen shows ha he behaviour is more duile and redisribuion o sresses is beer. Ulimae load arrying apaiy o asener is 7% higher and iniial slip ulus is 180% higher. Sine he ensile srengh o imber is usually no muh lower han he ompressive srengh he appliaions o ibre reinored polymers (FRP) or arbon ibre reinored polymers (CFRP) in imber have no been as requenly used as in masonry or espeially in onree sruures. The poenial o FRP in ombinaion wih seel and imber sruures has only been explored reenly. The main advanages o using FRP in pariular ompared o oher maerials (or example seel plaes) are heir orrosion resisane ligh weigh and lexibiliy whih allow onvenien and easy ranspor o he plae o ereion. The availabiliy o advaned omposie maerials has simulaed muh ineres in reinoremen o imber elemens espeially on glued laminaed beams. Timber is an unommon maerial or riial highway bridge sruures hough several appliaions o srenghening SSN: ssue 9 Volume Sepember 007

2 WSEAS TRANSACTONS on APPLED and THEORETCAL ECHANCS using FRP and CFRP o gain higher duiliy and bending resisane an be ound in his ield. Dagher and Breon (1998) researhed reinored laminaed imber beams in he ensile area using FRP lamellas. The es resuls showed an essenial inrease in bending resisane. Sevens and Criner (000) ondued an eonomi analysis o FRP gluelam beams. The resuls showed praial appliabiliy o FRP reinored elemens espeially or bridges o greaer spans where beam dimensions an be subsanially redued using he presened FRP soluion. The es resuls using arbon ibres in laminaed beams are presened in Bergmeiser and Luggin (001). Composie reinoremen on sawn imber elemens is less ommon in lieraure alhough many appliaions exis espeially or reroied reinoremen. Timber beams reinored by a layer o high-ulus omposie maerial may be analysed using a ransormed seion o an equivalen wood (Johns and Laroix 000) bu he inluene o omposie reinoremen on he bending resisane o he imber elemens is usually no pariularly high. Unlie onree or masonry he onribuion o he imber ension zones o he bending resisane oninues o be very high. Johns and Raine (001) demonsraed heir experimenal sudies using glass ibres o reinore sawn imber seions. The es resuls presened here show ha srengh inrease is ar greaer han hose predied by simple engineering bending alulaions. They onirm ha he omposie maerial adjaen o he sawn wood even wood o low qualiy has an essenial ee on he wood elemens. Sudies o he wood members reinored wih FRP maerials in he orm o shees (Trianaillou 1997) also show ha he eeiveness o FRP reinoremen an be quie high and ha is maximized when he ibres are plaed in he longiudinal direion o elemens. Use o HSF and CFRP or he reonsruion and srenghening o imber elemens opens new perspeives or imber sruures design. Coninuously dereasing pries o hese maerials mae he new ehnology more eonomial and ineresing. On he oher hand applying omposie ibres o imber sruures requires experiene and higher qualiy o wormanship han radiional reinoremens. a) Bernoulli s hypohesis is valid or eah subomponen b) maerial behaviour o all sub-omponens is linear elasi ) he disanes beween he dowels are onsan along he beam d) slip ulus is aen in plasi area or ulimae limi sae and elasi area or servieabiliy limi sae (Fig.) e)bending momen varying sinusoidally or parabolially. F - ore on asener FULS FSLS Ku Kser u - slip o asener Fig. : F-u diagram or slip in he onneion Basi deerminaions Equaion (1) shows he posiion o he neural axe o he omposed seion whih analogial o Euroode 5 [] or mehanially joined elemens: ( n A ( h + h ) n A ( h + h )) ( + + ) S z = = A n A A n A yi i (1) where z is posiion o overall neural axe rom enre o graviy o imber member n i is given by equaion () is siness oeiien given by equaion () A i is area o subomponen shown on Fig. and h i is hiness o eah sub omponen shown on Fig.. Analyi soluion or derivaion o load arrying apaiy and siness For design purposes a simpliied design mehod or mehanially joined elemens aording o Annex B o Euroode 5 [] is used. Expression o he so alled»mehod«is used in equaions wih he ollowing undamenal assumpions [4 5]: Fig. : Composie ross-seion SSN: ssue 9 Volume Sepember 007

3 WSEAS TRANSACTONS on APPLED and THEORETCAL ECHANCS Relaions beween ulus o elasiiy are: E E n = or onree; and n = or CFRP () E E where E is mean ulus o elasiiy o onree E is mean ulus o elasiiy o imber and E is mean ulus o elasiiy o arbon srip (ibre). Disanes rom enre o graviy o eah sub-omponen o main neural axe an be obained as wrien below: z z h h = z h h = z + or onree slab () or arbon srip (4) where z i is disane rom overall neural axe o enre o graviy o eah subomponen. n upper orms he siness oeiien o he aseners in plane beween onree and imber ( ) an be deined using Euroode 5 [] in he orm o: 1 = ; 1 + = π Em A si Kle (5) where l e is eeive (buling) lengh o omposed beam A is eeive area o onree plae s i is eeive spaing beween he asener and K is slip ulus aen rom Euroode 5 [] or dowel ype o aseners where or onree o imber onneions K ser (slip ulus or servieabiliy) should be based on mean densiy (ρ m ) o imber member and inally be inreased (muliplied) by 0. The siness oeiien in plane beween arbon srip and imber whih are glued ogeher is onsidered as ully onneed ( = 1.0). So he inal orm or K is: K K ser u 1.5 ρm d =.0 or servieabiliy limi sae (6) = Kser or ulimae limi sae (7) The eeive bending siness (E y ) e o mehanially joined elemens aen rom Euroode 5 [] an be analogially wrien in he orm o: By using relaions beween ulus o elasiiy rom equaions () he eeive bending siness is developed as: h b n + A z + 1 E y e = E (9) h b + A z + n ( A z ) 1 Deerminaion o bending bearing apaiy Normal sresses in omposie seion or eah o subomponens are deined in orm o: y Ei σ = = ( i zi ±Δ z) (10) W ( E y ) e where y is belonging bending momen around appropriae axe (Fig.) Δz is disane rom enre o graviy o eah subomponen o an edge (or any ibre) o eah subomponen E i ulus o elasiiy or appropriae subomponen. Wih usage o equaion (10) and (8) normal sresses in he edges o he onree slab (see Fig. 4) are obained in he orm o: σ n h y = z ± (11) where i represen haraerisi srengh o subomponen maerial under normal sress. For normal sresses in he edge ibres o he imber beam in orm o: σ y = z m ± h (1) For normal sresses in he enre o imber beam (Fig. 4): σ = (1) ( z ) 0 y For normal sresses in he edge ibres o CFRP (Fig. 4): σ n h y = z ± (14) h b E y = E e + A z + 1 ( ) h b E A z E A z ( ) (8) Aording o equaions rom (11) o (14) design bending momen (apaiy) an be evaluaed: yd = σ d W = id n z ±Δz ( ) i i i (15) SSN: ssue 9 Volume Sepember 007

4 WSEAS TRANSACTONS on APPLED and THEORETCAL ECHANCS where V z is belonging shear ore in direion o appropriae axe (Fig.) Δz is irs momen o area o seion above (or below) appropriae ibre in union o subomponen ulus o elasiiy and poenial siness oeiien ( ) b i is belonging widh o seion a appropriae ibre. Wih usage o equaion (1) shear sress in he boom edge o onree slab (see Fig. 5) is obained in he orm o: Fig. 4: Diagram o normal sress in ross-seion onree slab under ompression is deisive equaion (16) is obained: α α yd = y = n h z (16) imber beam is deisive (wha is mosly he ase) under bending normal sress equaion (17) is obained: yd = y = my h m m z + (17) n ases when he normal sress in he enre o imber beam is high he equaion (18) mus be used i equaion (19) is ulilled: h m 1+ > z yd = y = 0 m m z 0 (18) (19) τ max ( ( ) ) Vz n h b z = τ b R 1 () For deerminaion o maximal shear sress a neural axe o he omposie ross seion he equaion () is used: τ max h h z Vz n ( h b) z + b z 4 = b Shear sress in upper ibres o CFRP is given as: ( ( ) ) ( ) Vz Sy i n V i z n h b z τ = = τ b b R v () (4) where v τ i presen haraerisi shear srengh o subomponen maerial aordingly o Euroode 5 []. For onree plae aordingly o Euroode [4] haraerisi shear srengh is aen as: ( ) τ = τ + ρ (5) R 1 R 1 Where τ R presen basi haraerisi shear srengh o onree reading rom Euroode (4) = (1.6 - d) where d is sai heigh o onree slab in meers and ρ 1 is longiudinal reinoremen perenage. arbon srip is deisive under ension equaion (18) is obained: 1 1 yd = y = (0) h n z + Deerminaion o shear bearing apaiy Shear sresses in seion or any ibre are given as: ( ) V S Vz Syi ni τ = = (1) b b i Fig. 5: Diagram o shear sress in ross-seion Aording o equaions () - (4) design shear ore (apaiy) an be evaluaed as: SSN: ssue 9 Volume Sepember 007

5 WSEAS TRANSACTONS on APPLED and THEORETCAL ECHANCS i zdi = id ( ) Syi ni V b (6) onree slab is deisive he equaion (7) is obained: 1 1 b Vzd = Vz = τ R 1 (7) n ( ( h b) z ) And i imber beam is deisive he equaion (8) is obained: V = V = zd z m b 4 v m h h z n ( h b) z + b z (8) is also reommended o onrol shear beween web and langes aording o Euroode (4). Deerminaion o asener bearing apaiy Fore on one asener rom equaion (1) in union o disanes beween aseners (s i ) is given as: ( ) Vz Si E V i z Sy i ni Fi = si = s (9) i E ( y ) e On his poin onsruion parameers given by Euroode 5 [] mus be also onsidered as minimum inervals edge and end disanes or dieren ypes o aseners. n our ase he design ore on one asener or onneion beween onree slab and imber beam (see Fig. 6) is obained in he orm o: Vzd n( ( hb) z ) Fvd = si F (0) vrd Consequenly design shear ore is given as: F vr Vzd = Vz = m m n ( ( h b) z ) s i (1) Where he ompeen F vr is haraerisi load arrying apaiy per shear plane per asener given in Euroode 5 par 1-1 [] (aording o he Johansen yield heory) and iied aording o Euroode 5 par [5]. The load arrying apaiy o asener an be addiionally onrolled aording o Euroode 4 par 1-1 [6] in spie o deisive Euroode 5 par 1-1 []..5 Bending siness or servieabiliy limi sae n hese seion he deerminaion o bending siness or omposie seion is represened whih is needed or deerminaion o deleions and vibraions aording o Euroode 5 [] and Euroode [4]..5.1 nsananeous bending siness ( = 0) The equaions () - (4) remain he same equaions (1) (7) and (9) are iied by where usage o K ser insead o K u maes he only dierene in equaion (5)..5. Final bending siness ( = ) The ime dependen ees (dominaion o reep) an be assoiaed wih he ulus o elasiiy o eah maerial o sub-omponen. n equaions () he iied so alled eeive ulus o elasiiy aording o Euroode 5 [] and Euroode [4] are used in he orm o: E E in= 1 +Ψ de or imber sub-seion () E Ee = 1 + or onree sub-seion () φ( 0 ) Time dependen ees presened in onneion are assoiaed wih ulus K ser as iied equaion rom Euroode 5 []: Kser Kser in = (4) Ψ de + φ( 0 ) 1+ Fig. 6: Faseners and ores on i Tha have dire inluene on ( ) in equaion (5) and onsequenly on equaion (1) and on bending siness given in equaions (7) (8). There is sill some unerainy abou suiable elling ime dependen ees on omposiion o dieren maerials ogeher. However he inluene o reep in ulimae limi sae (ULS) alulaions mus no be negleed on suh ind o omposed seions. The reep has big inluene on rearrangemen o sresses by seion espeially when SSN: ssue 9 Volume Sepember 007

6 WSEAS TRANSACTONS on APPLED and THEORETCAL ECHANCS seion is omposed rom dieren reep depended maerials. Aording o [11] he sresses in a onree par o omposie elemen ross-seion derease in ime signiianly (rom 1.4 o 5 imes) while i slighly inreases in imber par (approximaely imes). n beore menioned sudy he reep ees presened in onneion beween imber and onree par o seion were no aen ino aoun alhough hey have big inluene on disribuion o sress. Also researh given by [1] shows omparison beween long erm servie load (18N on inlined srews and 10N on dowels wih onree onneors) and shor erm (4N on inlined srews and 5N on dowels wih onree onneors) load respeively. From ha an be onluded ha he rheologial phenomena (reep) o onneion in alulaion o deormaion - servieabiliy limi sae and also in alulaion o bearing apaiy o elemen seion - ulimae limi sae mus be aen ino aoun. n our presened sudy reep ees presen in onneion are aen ino aoun hrough inal slip ulus K serin. Numerial example.1 Geomerial and maerial properies Numerial analysis is perormed or omposie T seion o aual dimensions shown in Fig.7. For aseners beween onree plae and imber beam we use dowels aording o Euroode 5 [] and Euroode [8] o Φ0 mm and lengh l = 4 m a onsan inervals o s = 10 m. Dowel (bol) grade aording o Euroode [] is 8.8 ( yb = 640N/mm ub = 800N/mm ). aerial properies or he imber qualiy GL4h are aen rom EN 1194 [7] or he onree slab rom Euroode [4] and he CFRP SiaWrap-0C rom []. For all maerials saey aors appropriae European sandards are used. For FRP srenghening maerials is reommended o use TR55 Tehnial Repor 55 (Conree Soiey UK). All maerial properies are lised in Table 1. Table 1: Properies o used maerials For load 50% o permanen and 50% o long erm (sorage) aion is predied. On ha assumpion he proper saey aors or ulimae limi sae and iiaion aors or long erm ees an be deermined. The eeive lengh o beam (l e = 800m) is also predied or deerminaion o he siness oeiien.. Deerminaion o reep or imber beam Aording o Euroode 5 [] reep oeiien or imber is alulae as: ψ de (5) where de = 0.6 presens he inal reep oeiien or servie lass 1 given by Euroode 5 []. The aor or quasi-permanen value o aion is Ψ = 0.6 or long erm aion (C or D aegory) and Ψ = 1.0 or permanen aion given by Euroode 1. As already menioned 50% o permanen and 50% o long erm load were predied so he inal reep oeiien is alulaed as mean value beween orresponded permanen and long erm value o load: ψ Fig. 7: Cross-seion (dimension in m). Conree Timber SiaWrap C0/7 GL4h 0C E 0m [N/m ] m [N/m ] /.444 / 0 [N/m ] [N/m ].0.4 / ρ [g/m ] / 80 / ρ m [g/m ] ψ ψ g de p de de = + = + = 0.48 (6). Deerminaion o reep or onree plae Aording o Euroode [4] el developed by CEB Commision V and GTG9 (based on Rüsh el) he reep oeiien or onree is alulaed as shown urher where 50% relaive humidiy o he ambien environmen and 8 days age o onree a loading are predied. Equaion or reep oeiien a ime is given as: φ φ β ( 0 ) 0 ( = 0) (7) where φ 0 presen basi (inal) reep oeiien as: φ0 = φrh β( m ) β( 0) = =.87 where we use: SSN: ssue 9 Volume Sepember 007

7 WSEAS TRANSACTONS on APPLED and THEORETCAL ECHANCS - aor o relaive humidiy: RH φ RH = + = + = h wih RH = 50% A b h 4010 h0 = = = = 8.0m= 80mm u b + h aor o onree srengh: β ( m ) = = =.75 m 8 N wih m = + 8= 8 mm - aor o onree age a loading: 1 β ( 0 ) = = ( 0 ) wih 0 = 8dni The oeiien o ime developmen o reep (ully developed in presened ase): 0. 0 β ( 0 ) = = 1.0 β H + 0 where inal reep oeiien may be adoped or onree a 70 years: = = 5550days and age o onree a loading as already menioned: 0 = 8days The reep oeiien a ime = is inally alulaed and iied or mean ulus o elasiiy (el is assoiaed wih angen ulus) whih is used in presened sudy: Em 1 φ( 0 ) = φ0β( 0) = =.75 (8) E 1.05 (8).4 Resuls o numerial analysis SLS = 0 SLS = Unis Equaion K N/m (7) / (8) / (5) n.75 n / () z o m (1) z m () z m (4) z m (1) ye m 4 (9) (E) ye Nm (8) Table : Resuls o numerial analysis or SLS. ULS = 0 ULS = Unis Equaion K N/m (7) / (8) / (5) n.75 n / () z o m (1) z m () z m (4) z m (1) ye m 4 (9) (E) ye Nm (8) yd Nm (17) V zd N (8) V zd N (1) Table : Resuls o numerial analysis or ULS. Researh given by [1] shows ha he ulus o sliding aer ime period o 46 days is 6% o iniial value (K u(=46) = 0.6K u ) or wood-onree onneion made o Type C dowels aording o DN. n omparison o presened sudy rom Table. i is lear ha inal ulus o sliding is 8% o iniial value (K uin = 0.8K u ) or onneion made o dowels. Ceoi in [14] reommend push-ou ess o obain more realisi values o onneion siness..4.1 Corresponding normal and shear sress Corresponding normal sresses as onsequene o yd in = 0 are given wih equaions (11) o (14) and hey are represened in Fig. 8. Fig. 8: Corresponding normal sresses (in N/m ). Corresponding shear sresses as onsequene o Vzd a = 0 are given wih equaions () o (4) and hey are represened in Fig. 9. SSN: ssue 9 Volume Sepember 007

8 WSEAS TRANSACTONS on APPLED and THEORETCAL ECHANCS.5 Numerial omparison beween seion wih and wihou arbon srip Relaive omparison beween load bearing apaiy and bending siness o omposie beam wih and wihou arbon srip in union o variable inervals beween dowels (maerial and geomerial properies are he same as in he upper example) is shown in ollowing diagrams: Fig. 9: Corresponding shear sresses (in N/m ) d [Nm] d = 10.% [.5 Nm] d = 18.56% [.69 Nm] ailure o imber he average inome is 15.0% [8.46Nm] on bending apaiy a =0 wihou CFRP =0 wih CFRP =0 wihou CFRP =oo wih CFRP =oo d = 6.86% [1.77 Nm] he average inome is.9% [8.61Nm] on bending apaiy a =oo d = 15.0% [.85 Nm] Si [m] Fig. 10: Variabiliy o bending load bearing apaiy o omposie ross seion in union o spaing beween dowels. From diagrams in Fig 10. an be read iniial ( = 0) bending bearing apaiy (d in union o dowel s spaing) o he sruure wih arbon srip whih is 15% higher han he bearing apaiy wihou i. Hene he reep has big inluene on rearrangemen o sresses in seion espeially when seion is omposed rom dieren reep depended maerials. There an be also seen inal ( = ) bending bearing apaiy o he sruure wih arbon srip whih is 4% higher han he bearing apaiy wihou i. Vd [N] he average inome 1.00 is 4.66% on bending apaiy a =oo ailure o onree ailure o imber Si [m] he average inome is.61% on shear apaiy a =0 wihou CFRP =0 wih CFRP =0 wihou CFRP =oo wih CFRP =oo SSN: ssue 9 Volume Sepember 007

9 WSEAS TRANSACTONS on APPLED and THEORETCAL ECHANCS Fig. 11: Variabiliy o shear load bearing apaiy o omposie ross seion in union o spaing beween dowels. From diagrams in Fig 11. an be seen ha arbon srip has praially no onribuion o shear apaiy o omposie seion and onseuively ae no shear sress on i sel. Thereore in praie we do no use i or shear apaiy enlargemen in suh posiion. 7.70E+04 (E)esls [Nm] 7.0E E E E E E E % wihou CFRP wih CFRP he average inome is 11.0% on bending siness and onsequenly lower iniial deormaion a =0 d = 6.4% [0188 Nm] 11.1% 4.90E Si [m] Fig. 1: Variabiliy o iniial bending siness o omposie ross seion in union o spaing beween dowels. niial bending siness o srenghened seion is 11.0% higher han un-srenghened seion and inal bending siness even higher and i is 17.5% (seen rom diagrams in Fig 1. and Fig. 1). 0E+04 (E)eslsin [Nm] 00E+04 80E+04 76E+04 60E+04 40E+04 0E % wihou CFRP wih CFRP 00E Si [m] he average inome is 17.55% on bending siness and onsequenly lower iniial deormaion a = oo d = 1.0% [7480 Nm] 18.1% Fig. 1: Variabiliy o inal bending siness o omposie ross seion in union o spaing beween dowels. 4 Conlusion For presened omposed seions in mos ases (as well as in our sudy) he imber elemen is deisive a boom ension side under ulimae bending loading. Beause o ha a he srenghening wih arbon srip is so imporan espeially or inal bending bearing apaiy (beause CFRP srip in omparison o imber and onree do no reep). Presened sudy show an improvemen o 15% on iniial and 4% on inal bending apaiy urher a he same ime is ahieved improvemen o 11% on iniial and 17.5% on inal bending siness. Furhermore he beer ombinaion o sub-omponens an signiianly improve ees o inlusion o CFRP srip. For example higher bearing apaiy and bending siness an be ahieved wih usage o arbon srip wih higher Young s ulus beause he imber ulimae bending srain is relaively low regarding o CFRP. Under he inluene o rearrangemen o sresses in seion shear sream on dowels is dropping wih ime whih an be seen rom Table. Consequenly he iniial loading is deisive or deerminaion o aseners load bearing apaiy. in praise aer suh reinoremen (wih CFRP srip) beome deisive shear resisane o seion han is suiably o use he arbon srip in posiion o sirrups SSN: ssue 9 Volume Sepember 007

10 WSEAS TRANSACTONS on APPLED and THEORETCAL ECHANCS glued on web o imber beam similar lie ransverse seel reinoremen in seel reinored onree sruures. Reerenes: [1].Tajni Comparison analysis o omposie beam made o onree and imber wih and wihou arbon srip Fauly o Civil Engineering Universiy o aribor 007. []. Premrov P. Dobrila B.S. Bedeni Analysis o imber-ramed walls oaed wih CFRP srips srenghened ibre-plaser boards nernaional Journal o Solids and Sruures Vol.41 No. 4/5 pp [] CEN/TC 50/SC5 N17 Euroode 5: Design o Timber Sruures Par 1-1 General rules and rules or buildings Final dra pren Brussels 00. [4] pren Euroode : Design o onree sruures Par 1-1 General rules and rules or buildings Brussels 00. [5] ENV Euroode 5: Design o imber sruures Par Bridges Brussels [6] EN Euroode 4: Design o omposie seel and onree sruures Par 1-1 General rules and rules or buildings Brussels 004. [7] European Commie or Sandardizaion EN 1194: Timber sruures Glued laminaed imber Srengh lasses and deerminaion o haraerisi values Brussels [8] A. Frangi. Fonana Elaso-Plasi odel or Timber-Conree Composie Beams wih Duile Conneion. Sruural Engineering nernaional Vol.1 No.1 pp [9] K. Holshemaher S. Kloz D.Weibe Appliaion o Seel Fibre Reinored Conree or Timber- Conree Composie Consruions Laer No.7 pp [10] A. Ceoi Holz-Bron-Verbundonsruionen Sep Baueile onsruionen daails Düsseldor pp. E1/ [11] S. Kavaliausas A. Kvedaras K. Guršnys Evaluaion o long-erm behaviour o omposie imber-onree sruures aording o EC Uio ehnologinis ir eonominis vysymas Vol.X No.4 pp [1] L. Bob C. Bob Researhes regarding he behaviour o he omposie wood-onree loors ABSE Conerene Lahi nnovaive Wooden sruures and Bridges Vol.85 ABSE-APC-VBH pp [1] S. Taač Đ. aoševič P. Bogoičevič Rheologial researh o sliding ulus o he wood-onree onneion ABSE Conerene Lahi nnovaive Wooden sruures and Bridges Vol.85 ABSE-APC-VBH pp [14]A. Ceoi. Fragioomo S. Giordano Longerm and ollapse ess on a imber-onree omposie beam wih glued-in onneion - Springer Neherlands - aerials and Sruures Vol.40 number 1 January 007. SSN: ssue 9 Volume Sepember 007