Creep Behaviour of Heterogeneous Timber-UHPFRC Beams Assembled by Bonding: Experimental and Analytical Investigation
The purpose of this research was to investigate the
creep behaviour of the heterogeneous Timber-UHPFRC beams. New
developments have been done to further improve the structural
performance, such as strengthening of the timber (glulam) beam by
bonding composite material combine with an ultra-high performance
fibre reinforced concrete (UHPFRC) internally reinforced with or
without carbon fibre reinforced polymer (CFRP) bars. However, in
the design of wooden structures, in addition to the criteria of
strengthening and stiffness, deformability due to the creep of wood,
especially in horizontal elements, is also a design criterion. Glulam,
UHPFRC and CFRP may be an interesting composite mix to respond
to the issue of creep behaviour of composite structures made of
different materials with different rheological properties. In this paper,
we describe an experimental and analytical investigation of the creep
performance of the glulam-UHPFRC-CFRP beams assembled by
bonding. The experimental investigations creep behaviour was
conducted for different environments: in- and outside under constant
loading for approximately a year. The measured results are compared
with numerical ones obtained by an analytical model. This model was
developed to predict the creep response of the glulam-UHPFRCCFRP
beams based on the creep characteristics of the individual
components. The results show that heterogeneous glulam-UHPFRC
beams provide an improvement in both the strengthening and
stiffness, and can also effectively reduce the creep deflection of
 H. S. Pham, “Optimisation et comportement en fatigue de la connexion
bois-BFUP pour de nouveaux ponts mixtes,” Docteur de l’Ecole
Nationale des Ponts et Chaussées, 2007.
 Gary M.Raftery, “Bonding of FRP materials to wood using thin epoxy
gluelines,” Int. J. Adhes. Adhes., vol. 29, pp. 580–588, 2009.
 R. Gutkowski, K. Brown, A. Shigidi, J. Natterer, “Laboratory tests of
composite wood–concrete beams,” Constr. Build. Mater., vol. 22, pp.
 E. Ferrier, A. Agbossou, and L. Michel, “Mechanical behaviour of ultrahigh-
performance fibrous-concrete wood panels reinforced by FRP
bars,” Compos. Part B, vol. 60, pp. 663–672, 2014.
 J. Kanócz and V. Bajzecerová, “Influence of rheological behaviour on
load-carrying capacity of timber concrete composite beams under long
term loading,” Steel Struct. Bridg., vol. 40, pp. 20–25, 2012.
 M. Yahyaei-Moayyed, F. Taheri, “Experimental and computational
investigations into creep response of AFRP reinforced timber beams,”
Compos. Struct., vol. 93, pp. 616–628, 2011.
 ASTM-D198, “Standard Test Methods of Static Tests of Lumber in
Structural Sizes,” 2003.
 José Sena-Cruz, Marco Jorge, Jorge M. Branco, Vítor M.C.F. Cunha,
“Bond between glulam and NSM CFRP laminates,” Constr. Build.
Mater., vol. 40, pp. 260–269, 2013.
 Martin Schäfers, “Investigation on bonding between timber and ultrahigh
performance concrete (UHPC),” Constr. Build. Mater., vol. 25, pp.
 CEN, “Eurocode 5 –Design of Timber Structures – Part 1-1: General
Rules and Rules for Buildings,” Comité Européen de Normalisation,
Bruxelles, Belgium, 1995.
 N. Khorsandnia, J. Schӓnzlin, H. Valipour, and K. Crews, “Timedependent
behaviour of timber–concrete composite members: Numerical
verification, sensitivity and influence of material properties,” Constr.
Build. Mater., vol. 66, pp. 192–208, 2014.
 A. Ceccotti, “Long-term and collapse tests on a timber-concrete
composite beam with glued-in connection,” Mater. Struct., vol. 40, pp.
 M. Fragiacomo, “Simplified approach for the long-term behaviour of
timber-concrete composite beams according to the Eurocode 5
provisions,” Italy, 2006.
 A. Hanhifirvi, “Computational method for predicting the long-term
performance of timber beams in variable climates,” Mater. Struct.
Constr., vol. 33, pp. 127–134, 2000.
 AFGC, “Bétons fibrés à ultra-hautes performances Ultra High
Performance Fibre-Reinforced Concretes.” par le groupe de travail
AFGC / SETRA, 2002.
 T. V. Toratti, “Service limit states: Effects of duration of load and
moisture on deformations,” Cost E24 Reliability of Timber structures,
 Aicha Kamen, “Comportement au jaune âge et différé d’un BFUP
écrouissant sous les effets thermomécanique,” Ecole polytechnique
fédérale de Lausanne, 2007.