glulam ties manufactured with pinus oocarpa and ... adhesives... · glulam ties manufactured with...

Glulam ties manufactured with Pinus oocarpa and polyurethane adhesive

Felipe Hideyoshi Icimoto PhD. Student In Science and Materials Engineering University of São Paulo - EESC/USP - Brazil

Toronto, 10/10/2013.

Introduction

• The railway consists of two parts:

– The infrastructure;

– The superstructure.

Glulam ties with polyuretane adhesive 2

Infrastructure

For example: Railway bridges.


Source: ALL (2011).

Source : ALL (2011).

Superstructure

• One of the most important components of the superstructure is the tie.


Source : Adapted from Porto (2011).

Functions and characteristics of ties are

• Strength and stiffness to receive the loads of vehicles and transmit them to the ballast;

• Partially dampen vibrations;

• Providing support to the rails, allowing the fixing and keeping the distance unchanged between them (gauge);

• Suitable electrical insulation;

• High durability.


Ties are manufactured

Concrete: Plastic:

Source: Dorbrás (2011). Source: Michel (2011).

Steel: Wood:

Source: FC Construções (2011). Source: ALL (2011).


Tropical Hardwoods

• In Brazil most of the ties are from tropical hardwoods, as Maçaranduba, Aroeira, Ipê and Jacarandá;

• But due to the increasing scarcity of these tropical hardwoods;

• Consequent increase in price;

• The substitution by other materials and other woods, more abundant and available at competitive prices, has been stimulated.


Plantation Forests

• These features are mainly found in plantation forests;

– For example: Pinus and Eucalyptus reforestation.


Plantation Forests

• Being the Eucalyptus sawn ties very used in Brazil.

• But the Pinus has some advantages over Eucalyptus, such as: – Very easy to machining ;

– Excellent penetration and interaction with adhesives;

– High retention of preservative treatment.


Brazilian Standard Ties

• Being the ties a structural product and a wood product, many of the recommendations standards can and should be applied;

• Based on The American Railway Engineering and Maintenance-of-Way Association, AREMA:2009 - Manual for Railway Engineering;

• And making the necessary adjustments to the Brazilian context. As a result we have the recently approved the Brazilian Association of Technical Standard, ABNT NBR7511:2013 Wood sleepers - Requirements and test methods.


Aim

• This aim of this study is to characterize the physical and mechanical properties of solid sawn timber ties and Glulam ties manufactured with Pinus oocarpa and polyurethane adhesive commercially known as HB Purbond S309;

• Evaluating the performance of the polyurethane adhesive;

• Evaluate their properties and compare the values obtained with the values recommended by the standard ABNT NBR7511:2013 Wood sleepers - Requirements and test methods.


Materials and Methods

• The wood used to produce Glulam and solid sawn timber ties was:

– Pinus oocarpa CCA-treated;

• Planted in the city of Catalão, state of Goias - Brazil.

12 Glulam ties with polyuretane adhesive


• Glulam ties:

– Lamellas utilized were classified according to ABNT NBR7190:2012 Design of timber structures.



• The adhesive used for bonding of the wooden lamellas was:

– Polyurethane adhesive;

– Used for bonding of structural elements;

– Water-resistant;

– Cold bonding;

– Automatically applied.



• Automatically Pressed


Ties ready to be tested


Properties Investigated

• Number of specimens tested for mechanical properties investigated:


Properties Number of specimens

Sawn Glulam

Weight 6 6

Density 6 6

Modulus of Elasticity 6 6

Modulus of Rupture 6 6

Screw pullout 12 12

Shear of glue line dry - 12

wet - 12

Delamination - 12

Source: ABNT NBR7511: 2013 Wood sleepers - Requirements and test methods

Bending - Center negative

• Determines properties of strength and stiffness in bending (MOR and MOE).



Bending - Center negative


Screw pullout

• Determines ability to resist withdrawal for the rail fastening system.



Shear of glue line

• Determines the resistance of material to the shear of glue line (dry and wet).


Delamination


• Determines the quality of bonding.

Results and Discussion

• The results are presented as average value;

• The table shows the results of weight and density to the studied ties, as well as standard values for the density of Pinus oocarpa wood.

• The Glulam ties showed greater weight and density when

compared to the solid sawn timber ties, due to the classification of

the lamellas that compose them.


Physical properties of ties tested

Ties Weight (kg) Density (kg/m³)

Work ABNT NBR7190:1997

Glulam 42 600 538

Sawn 37 524

Results and Discussion

• The Brazilian Standard classified the ties in class I and class II for mechanical properties:

Mechanical properties values

Properties Symbol Unit Standard values

Class I Class II

Modulus of Elasticity MOE MPa 13000 10000

Modulus of Rupture MOR MPa 50 40

Screw pullout Ra90 kN 25 20



Results of bending test (MOE)

• The Glulam ties reached values of MOE by the Brazilian Standard ABNT NBR7511: 2013 related to Class II, with value 84% higher than the solid sawn timber ties.


Results of bending test (MOR)

• The solid sawn timber ties did not reach the minimum values for the MOR;

• The Glulam ties showed superior value to those established by the Brazilian standard ABNT NBR7511:2013 regarding Class II.


Mode of rupture for Glulam ties

• For all Glulam ties rupture occurred in the wood, demonstrating the efficiency of polyurethane adhesive used for bonding of wooden lamellas.


Results of Screw pullout (Ra90)

• The values of the screw pullout for all ties were higher than those stipulated requirements by the Brazilian standard relating to Class I.


Screw pullout (Ra90)


• The efforts solicitation for the screw pullout in the perpendicular direction to the glue line was not enough to change the connection between wood and adhesive.

Delamination

• The delamination test showed that all the ties did not suffer opening in the glue line, without bonding problems.

Shear of glued line • The shear strength when saturated was

reduced by 43%. The failure modes were satisfactory.


Analysing of cross section

• The solid sawn timber ties showed significant amount of pith;

• The Glulam ties does not have this problem because their Lamellas are selected and classified.


Summary of the results

Summary of the results of the tested ties

Properties Ties

Sawn Glulam

Modulus of Elasticity (MOE)

Modulus of Rupture (MOR)

Screw pullout (Ra90)

Shear of glue line (dry) (fv0)

Shear of glue line (wet) (fv0)

Delamination



Reached Class I

ReachedClass II

Reproved

Conclusions

• The limiting properties for Pinus oocarpa ties are strength and bending stiffness.

• The Pinus oocarpa Glulam ties reached values for Class II for the use as railway ties, but they were very close to their limits.

• Therefore it is recommended to use only lamellas classified as SS, or use of another specie.


Conclusions

• The wood of Pinus oocarpa, the polyurethane adhesive and CCA treatment had good interaction with each other, showing no quality problems in bonding.

• The use of the polyurethane adhesive showed to be technically viable to manufacture ties.

• The characteristic mono-component adhesive is important because it makes it simple and fast handling during the production process.


Conclusions

• The Glulam as an alternative for the production of ties may widen the use of reforestation wood in applications where only tropical hardwoods are used.


Acknowledgment

• The authors express their gratitude to CNPq

for granting scholarships;

• The Engineering of Materials Department;

• The Wood and Timber Structures Laboratory;

• The University of São Paulo – USP

that enabled the development of this work.


References

• AMERICA LATINA LOGISTICA. (2011). Railway Bridges. Available in:

<http://pt.alllogistica.com/all/web/default_pti.asp?idioma=0&conta=45. Access in: 23 feb.

2011. (in Portuguese).

• BRAZILIAN ASSOCIATION OF TECHNICAL STANDARD. ABNT NBR 7511: Wood sleepers –

Requirements and tests methods. Rio de Janeiro, 2005. (in Portuguese).

______NBR7511: Wood sleepers – Requirements and tests methods. Rio de Janeiro, 2013. (in

Portuguese).

______NBR7190: Design of timber structures. Rio de Janeiro, 2012. (in Portuguese).

• DORBRAS, (2011). Concrete ties. Available in: <http://dorbras.com.br/>. Access in: 07 may.

2011. (in Portuguese).


References

• MICHEL, Fernando Dutra. Railway Superstructure: Ties. Class noites: Superstructure (ENG 09030.

Available in: <http://www.producao.ufrgs.br/arquivos/disciplinas/411_aula_5_dormentes.pdf>.

Access in: 29 apr. 2011. (in Portuguese).

• PORTO, Telmo Giolito. PTR 2501-Ferrovias. University of São Paulo. Available in

<http://www.poli.usp.br/d/ptr0540/download/ApostilaNova.pdf>. Access in: 10 feb. 2011. (in

Portuguese).

• FC CONTRUÇÕES (2011). Superstructure Construction. Available in:

<http://fcconstrucoes.com.br/MFO/MFO001R0.pdf>. Access in: 05 may. 2011. (in Portuguese).


Obrigado


Felipe Hideyoshi Icimoto

[email protected]

The different and more ecological paths are what make us better each day

Thank you

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