Eucalyptus Timber Assignment 2022

Eucalyptus Timber 1
EUCALYPTUS TIMBER
Name
Course
Professor
University
City/state
Date

Eucalyptus Timber 2
SUMMARY OF WORK COMPLETED
This section briefly summarizes the work completed so far in the draft report. Reference has
been given to various sections included in this draft report. Section 1.1 provides information on
the overview of forest cover in Australia, factors driving increasing demand of timber in
Australia and the characteristics and usage of eucalyptus timber in Australian construction
industry. The problem statement has been discussed in section 1.2 stating the significance of
conducting this research and the suitability of eucalyptus timber for structural applications.
Project scope, aim and objectives are stated in Section 1.3.1-1.3.3 while research questions are
listed in Section 1.4. Section 2 provides a detailed discussion about structural timber. The
discussion has included introduction and uses of structural timber, advantages of using structural
timber in construction projects, a brief summary of hardwoods and softwoods/solid woods
(including their characteristics, examples, strengths and weaknesses) and the basic properties of
wood.
Relevant literature has been reviewed in section 3 to find out what other researchers have done
before particularly those that completed their studies by conducting tensile and compression tests
so as to investigate applicable properties of structural timber, with a focus on eucalyptus timber.
A total of 20 published journal articles have been reviewed. The review included a brief
summary of the reasons why the researchers conducted the study, methods used to complete the
study and findings from the study.
Several limitations that may hinder successful completion of the research or the ones likely to
affect the accuracy of results from the study have also been identified in Section 4. I have
completed the draft by writing its summary in Section 5.

Eucalyptus Timber 3
Table of Contents
1. Introduction.......................................................................................................................................4
1.1. Overview.....................................................................................................................................4
1.2. Problem statement.....................................................................................................................6
1.3. Project Scope, Aim and Objectives...........................................................................................7
1.3.1. Scope...................................................................................................................................7
1.3.2. Aim......................................................................................................................................7
1.3.3. Objectives...........................................................................................................................7
1.4. Research questions.....................................................................................................................8
2. Overview of structural timber..........................................................................................................8
2.1. Introduction...............................................................................................................................8
2.2. Uses.............................................................................................................................................9
2.3. Advantages.................................................................................................................................9
2.4. Hardwoods...............................................................................................................................10
2.5. Softwoods/solid woods.............................................................................................................10
2.6. Basic wood properties..............................................................................................................11
3. Literature Review............................................................................................................................12
4. Limitations.......................................................................................................................................25
5. Summary..........................................................................................................................................26
References................................................................................................................................................28

Eucalyptus Timber 4
1. Introduction
1.1. Overview
Timber is a natural common product in the Australian construction industry and has been in
use since the ancient times. The popularity of timber in Australia has been increasing over the
past few decades mainly because of global warming and climate change. Construction industry
contributes significantly to climate change due to use of large amounts of less sustainable
materials such as concrete, metals and plastics. To help resolve the problem, the Australian
government has formulated policies that promote sustainable development. One of these policies
is use of alternative natural materials that are more sustainable. As a result of this, stakeholders
in the Australian construction industry are rapidly turning to timber mass construction as an
alternative to reinforced concrete and metals (Kremer & Symmons, 2015).
Timber has properties that can meet most of the basic structural requirements of structures,
such as buildings. There are also numerous species of timber, each with unique properties. These
properties influence the performance and durability of the structures. The focus of this study is
on eucalyptus timber. Eucalyptus timber is a biodegradable, hypoallergenic, insulating and
recyclable material. It is natural, non-polluting, environment-friendly and 100% renewable hence
it is a sustainable material (Quartucci, et al., 2015). Some of the key benefits of eucalyptus
timber include: very durable hence can be used as a structural member (Nogueira, et al., 2019),
versatile thus suitable for use in indoor and outdoor construction, cost effective because it is
readily available, renewable, highly durable, and is available in different sizes (length and
diameter) and species. It is most likely that the sustainability aspect of eucalyptus timber is one
of the key factors that have contributed to its high demand not only in Australia but also in other
parts of the world such as the U.S., Europe, Asia, China and India (Liao, et al., 2017). In

Eucalyptus Timber 5
Australia, timber is no longer a material used for framing, fitout and features. There are new
engineered timber products that are changing Australia’s building game. The three main timber
materials used in Australia are: laminated veneer lumber (LVL), cross-laminated timber (CLT)
and glue laminated timber (GLT). 25 King in Brisbane and 55 Southbank Boulevard in
Melbourne are among the spectacular high-rise buildings in Australia that are made from CLT.
Eucalyptus is an evergreen hardwood tree that is native to Australia and there are nearly 900
species, most of which are native to Australia. It is the widely planted hardwood tree worldwide
and is estimated to cover more than 19 million hectares of land (Albaugh, et al., 2013). It is
estimated that 75% of forests in Australia are eucalypt forests. This makes supply and
availability of eucalyptus timber in Australia to be high hence stakeholders in the building and
construction industry can easily get and use it at a reasonable price. Eucalyptus timbers are very
tough and durable, which make them suitable for use in making structural components of
buildings and other structures (Lahr, et al., 2018). The eucalyptus timber also contains natural
oils that have water-, moisture- and insect-repelling properties that help in protecting the timber
from decay and rot thus increasing its durability.
Use of eucalyptus timber as a structural component is not a new concept in the building and
construction industry but has been ongoing for many centuries (Blackburn, et al., 2018);
(Derikvand, et al., 2017). The aboriginal population has been using this tree since ancient times
for several purposes, including in buildings, pulp industry and oil that is used in perfumery,
beverages, food, cosmetics, phytotherapy and aromatherapy (Vecchio, et al., 2016). The
sustainability aspect of eucalyptus timber has definitely increased its value in the building and
construction industry. However, it is always important to perform relevant tests on eucalyptus
timber before using it so as to confirm its mechanical properties. Since eucalyptus timber is

Eucalyptus Timber 6
anisotropic, it is important to perform tests both along and across the grain (Naylor, et al., 2012).
Several studies have shown that the compressive strength, tensile strength and modulus of
elasticity of wood is higher along the grain than across the grain (Manriquez & Moraes, 2010);
(Oh, 2011). The compressive and tensile strength values give an idea on how the timber will
behave when subjected to different design loads (Hein & Brancheriau, 2018). Therefore the
increase in intake of structural timber in Australia presents an opportunity for further research on
the properties of eucalyptus timber and how to use them in predicting the performance of timber
structures. This can improve the strength grading criteria of eucalyptus timber and also has the
potential of significantly increasing usage of eucalyptus timber in the Australian construction
industry.
1.2. Problem statement
Usage of timber in the Australian construction industry is increasing rapidly due to the
sustainable benefits of timber and its availability. Because of climate change and sustainable
development goals, there is need to build more structures using timber. But as more timber
structures are built, it is important to ensure that the properties of timber used meet the
requirements of industry standards. This includes the physical, chemical and mechanical
properties. Eucalyptus is the commonest tree species in Tasmania and several other states. It is
estimated that eucalyptus makes up 75% of forests in Australia. This means that if more
eucalyptus trees are planted, conserved and harvested to manufacture, structural and engineered
timber products, supply of construction timber in Australia can be significantly increased.
However, use of eucalyptus as a structural timber has been low in Australia due to the
misconception that it has inferior structural properties. This contrary to findings from various
studies, which have revealed that eucalyptus timber has properties that make it suitable for

Eucalyptus Timber 7
structural applications. Therefore it is important to perform studies that will evaluate the
properties of eucalyptus timber and prove that they meet the fundamental structural requirements
of relevant construction standards and building codes. This will improve confidence in
eucalyptus as a structural timber thus increasing its usage and overall supply of timber in the
Australian construction industry.
1.3. Project Scope, Aim and Objectives
1.3.1. Scope
This project will investigate the compressive and tensile strength properties of eucalyptus
timber from Tasmania, Australia, by performing applicable tests according to Australian
standards. The experimental data collected will be used to develop numerical models for
predicting the compressive strength and tensile strength properties, and the performance of
eucalyptus timber. The study will also assess the potential of eucalyptus timber transforming the
Australian construction industry if it is fully accepted by the stakeholders.
1.3.2. Aim
The main aim of this research project is to investigate the mechanical properties of eucalyptus
timber (particularly the compressive strength and tensile strength) so as to determine its
suitability for structural applications in the construction sector. This will improve people’s
confidence in eucalyptus timber and its overall use in the construction industry, which is
essential in achieving sustainable development.
1.3.3. Objectives
The main objectives of the current study are as follows:
1. To conduct tensile tests and compression tests on eucalyptus timber samples;

Eucalyptus Timber 8
2. To evaluate the compressive strength and tensile strength properties of eucalyptus timber;
3. To develop a prediction model for compressive and tensile strength properties of
eucalyptus timber, and the performance of eucalyptus timber structures.
4. To develop a numerical model for the prediction of the performance of eucalyptus timber
elements and/or structures.
1.4. Research questions
The main questions in this research project are:
1. Does the properties of eucalyptus timber meet the fundamental structural requirements of
relevant construction standards and building codes in Australia?
2. What is the potential of eucalyptus timber reducing the demand for construction timber in
Australia?
2. Overview of structural timber
2.1. Introduction
Wood is a natural material that has a wide range of uses. There are numerous species of wood
but the typical composition of wood comprises of cellulose, lignin, hemicelluloses and
extractives (Reyes-Rivera, et al., 2015). These chemical constituents influence the properties of
wood (Shanbhaq & Sundararaj, 2013). Wood can be processed into structural timber or
engineered timber for use in the construction of structural components, such as framing systems,
studs and joists. There are numerous types of wood products, including: sawn wood and round
wood, veneer, plywood, laminated wood, particle board, and fiber-board. In general, wood has
numerous uses, advantages. There are also different types of wood, each with unique properties
(Harte, 2009). It is important to investigate the properties of wood before choosing the most

Eucalyptus Timber 9
suitable type of wood for the intended use. Some of the main properties of structural timber are
compressive strength and tensile strength. These properties influence the ability of the timber to
resist compressive and tensile loads. Typical structures, such as buildings, have both
compressive and tensile loads. These structures require structural components that have the
capacity to support both the structural and tensile loads.
The chemical properties of timber are intrinsically sophisticated but studies and previous
experience have shown that the properties of timber make it suitable for use as a construction
material. This material has substantial amount of tensile strength and compressive strength that
meet the desired strength of most structures. Another major advantage of timber is that it is a
natural material, which is readily available in all parts of the world hence economically feasible.
2.2. Uses
Wood has a variety of uses. Some of these include: construction (making building
components such as frame systems, floorings, roofs, walls, partitions, formworks and
scaffolding) (Ramage, et al., 2017), decorating gardens, fencing, creating and making artworks,
utensils, sports equipment, toys, musical instruments, shipbuilding, producing furniture, making
stationery and used as fuel.
2.3. Advantages
There are numerous advantages of using wood in construction. Some of these include:
lightweight (Foster, et al., 2017); strong; versatile; low waste volume; low embodied energy;
quick build time (constructionability), reduced site labour; high durability; high energy
efficiency; superior thermal properties; low heat conductivity; easy to maintain; attractive (high
aesthetic appeal); elastic; provides great heat and noise insulation (superior acoustic properties);

Eucalyptus Timber 10
great electrical insulation properties; recyclable and reusable; natural, renewable and sustainable
hence environment-friendly (Kremer & Symmons, 2015); (Malone, et al., 2014).
2.4. Hardwoods
Hardwoods are one kind of wood that are mainly from deciduous trees that have broad
leaves (Diffen, 2013), which are shed during winter. Examples of hardwoods are: mahogany,
oak, beech, ash, walnut, maple, cherry, mango, rosewood, birch and teakwood. Hardwoods are
known for their attractive grains, which make them suitable for use in making decorative
woodworks and furniture. Other characteristics of hardwoods include: have slower growth rate,
are more expensive than softwoods, are denser than most softwoods, are more fire resistant than
softwoods and have greater compressive strength than softwoods (Aigbomian & Fan, 2013).
However, it is not always true that hardwoods are harder and stronger than softwoods.
2.5. Softwoods/solid woods
Softwoods are another type of wood that are mainly from evergreen trees (coniferous
trees) that have needlelike leaves. Examples of softwoods are: cypress, hemlock, cedar, redwood,
spruce, pine and fir. Softwoods are usually from tall, straight trees, which make them suitable for
use in construction works. Their surface is softer but they remain strong. Their softness and
lightweight properties make softwoods easier to work with compared with hardwoods.
Sometimes softwoods are mistaken to be weaker than hardwoods but this is not always the case.
There are some softwood species that have high tensile strength as hard as hardwoods, or even
greater than them (Antonsson, et al., 2009). Proper maintenance and treatment of softwoods can
also make them durable like hardwoods.
The cells of softwoods are open hence their microstructure does not have vessels. This
improves the ability of softwoods to absorb adhesives, preservatives and finishes. The superior

Eucalyptus Timber 11
absorption property makes softwoods very durable. They are also resistant to moisture, bacteria,
termites and fungal attacks, Softwoods are commonly used in making roofs, fencing posts,
partitions (internal wall structures), and other building components like doors, fittings, fixtures,
fireboards, ventilation panels, and plasterboards, among others. Generally, softwoods have
adequate properties for structural use, including moisture content, density, basic density, tensile
strength, bending strength, shear strength, hardness, modulus of elasticity, heat capacity, thermal
conductivity and calorific value.
2.6. Basic wood properties
Properties of wood influence its quality. These properties must be examined when selecting
wood to be sure of its qualities. The properties include both physical and mechanical properties.
Some of these properties include the following (Mou, (n.d.)):
Appearance and colour: wood has a dark colour, shining surface and give a sweet smell
when fresh. The appearance increases the aesthetic value of the timber elements and the timber
structure as a whole.
Shape and weight: wood is able to retain its shape during seasoning and is heavy enough
to resist substantial loads. Lightweight is a key characteristic of timber and should be maintained.
Proper storage can also help to preserve the shape of the timber.
Strength: wood has adequate strength that enables it to resist substantial structural loads.
The strength properties can be estimated from relevant tests, including compression and tensile
tests.
Hardness: wood is hard enough to resist different types of deteriorations. The hardness is
influenced by several factors, such as type of species, source, age and defects.

Eucalyptus Timber 12
Toughness: wood has adequate toughness that enables it to resist splitting and shocks
caused by vibrations and avoid breaking in bending. Toughness is also dependent on factors such
as type of tree species, growth conditions and defects.
Durability – wood has the capacity to resist worms, fungi and atmospheric effects for a
longer time. After harvesting, the wood must be stored properly and treated using appropriate
methods so as to increase its durability.
Elasticity: wood is able to regain its original shape when loads acting on it are removed.
The elasticity prevents it from buckling or breaking when subjected to loads.
Workability: wood is easily workable, meaning that it can be cut, shaped and sized quite
easily. This can be done using simple tools and equipment, or in the factory by use of advanced
machines, depending on the desired properties of the timber.
Defectless: wood has to be free from defects such as dead/live knots, sap, check, split and
shakes, so as to achieve greater mechanical and physical properties. This requires vigilant
selection of trees or throwing away sections with numerous defects.
Other wood properties include: grain, moisture content, specific gravity, density, swelling and
shrinkage, warping, elasticity, free of abrasion and soundness.
3. Literature Review
Chen (2017) conducted an empirical study to examine the mechanical properties of laminated
veneer lumber (LVL) (an engineered wood product), manufactured from eucalyptus nitens. This
study was motivated by the increasing demand for veneer products in Australian market and the
promising potential of using this product for structural applications. The author sought to
establish the relationship between veneer stiffness and LVL panels’ mechanical performance. To

Eucalyptus Timber 13
achieve this, the author performed compression test so as to determine the characteristic stiffness
of the veneer product and its accompanying strength properties. He tested a total of 150
eucalyptus nitens specimens. The results obtained from the tests revealed that there was no
relationship between veneer stiffness and the mechanical properties of veneer panels. The
performance of the veneer panels tested was similar across all the stiffness categories of the
veneer specimens. The results showed that but logs had the lowest log MOE and density values
whereas the top buts recorded the highest values of density and log MOE. Also, eucalyptus trees
grown in high moisture content regions were bigger in size but had lower MOE and density due
to prolonged drying process that increases shrinkage of the logs. The results also revealed that
there is a correlation between veneer stiffness and log modulus of elasticity (MOE) hence log
assessment can be used to predict veneer stiffness of LVL panels.
Derikvand, et al. (2019) studied in detail the mechanical and physical properties of
eucalyptus nitens timber obtained from unthinned and unpruned forestry systems. The purpose of
the study was to determine if the mechanical and physical properties of the timber makes it a
suitable material for use in making high-value structural products. The authors performed several
tests including compressive test and tensile test. It was found from the study that basic density
has a significant influence on mechanical properties of eucalyptus nitens timber. Generally, an
increase in moisture content caused a corresponding increase in density of the eucalyptus nitens
timber. Hardness, modulus of rupture, IBS and compressive strength parallel to the grain (CPA)
values were highly sensitive to density variations; cleavage, tensile strength parallel to the grain
(TPA), compressive strength perpendicular to the grain (CPE) and modulus of elasticity values
were moderately sensitive to density variations; and shear strength was less sensitive to density

Eucalyptus Timber 14
variations of the timber. Presence of knots was also found to be directly proportional to shear
strength and inversely proportional to the tensile strength of the timber.
Ravenshorst (2015) carried out a study to examine the suitability of using timber from local
forest plantations as a structural construction material. The aim of the study was to develop
models of predicting strength of structural timber using the values of its mechanical and physical
properties. The author collected relevant data using both visual grading and machine grading
methods. Visual grading was used to identify timber defects (including knots, wane, compression
failures, fissures and slope of grain (or grain angle deviation), and machine grading methods
used included compression test and tensile test. Results obtained from the study revealed that
visual grading is not an accurate method of examining strength properties of timber and the
presence of numerous defects on timber logs affect their strength and stiffness properties. The
author also found that density is a key parameter that affect the stiffness and strength of timber.
Density was found to be linearly correlated with stiffness and strength of clear timber. According
to Ravenshorst, predictable strength reducing features are slope of grain and knots whereas
unpredictable strength reducing features are large fissures and compression failures. The author
also formulated different equations and developed several models to predict stiffness and
strength of structural timber by taking into account several parameters that affect these
properties.
Different timber species have unique physical and mechanical properties. Awan, et al. (2012)
carried out an experimental study to compare physic-mechanical properties of a farm-grown
timber species (Eucalyptus camaldulensis) with those of conventional timber species (Dalbergia
sissoo, Cedrus deodara and Acacia nilotica). This study was carried out so as to investigate the
assumption that E. camaldulensis produced poor wood quality products. The authors conducted

Eucalyptus Timber 15
relevant tests on the timber samples in accordance with ASTM D-2395-93 and ASTM D-143-94
procedures. The properties tested include: density, impact and static bending, tensile strength,
capacity of nail holding and maximum compression parallel and perpendicular to the grain.
Results obtained from the study showed significant differences in properties of all the four
species of timber tested. The physical and strength properties of E. camaldulensis were
comparable to those of D. sissoo and A. nilotica, and even superior to C. deodara in other
properties such as density, tensile strength and modulus of rupture. Therefore E. camaldulensis
was found to be a suitable substitute for the other conventional timbers whose supply has been
declining over the years.
As postulated by Moshtaghin, et al (2016), mechanical properties of timber are affected by a
variety of factors, such as age, structural imperfections, location of timber, and load history,
among others. These authors conducted an experimental study to characterize the effect of length
on the tensile strength and elasticity of wood along the grain direction. To complete their study,
they collected a total of 165 specimens from Norway spruce timber, prepared, conditioned and
fabricated them using CNC machine before subjecting them to tests. The length of specimens
tested varied between 2mm and 128mm. The specific tests performed were quasi-static
longitudinal tensile tests. The results obtained from the study revealed that there was spatial
variability in the local elastic modulus along the length of the timber specimens. This variability
was attributed to the wood’s irregular mesostructure changes, including fiber waviness, fiber
misalignment, and increase in ring thickness. The specimens experienced brittle failure and the
fracture surfaces of those with higher strength level formed sharper angles than those with lower
strength level. The results also showed linear relationships between strength and local elastic
modulus, effective elastic modulus and density, and strength and density of timber. However, the

Eucalyptus Timber 16
spatial variability of these mechanical properties was random. The authors also concluded that
the strength values obtained from tensile tests can be used to develop regression models for
predicting mechanical properties and performance of structural timber.
Ahmad, et al. (2010) investigated the tensile strength properties of structural size timber. The
authors conducted this study after realizing that the tension stress values of structural timber
found in Malaysian code of practice MS544: Part 2:2001 were not determined through tests but
were directly taken as 60% of small clear timber specimens’ bending strength values. In their
study, the authors collected specimens from three different Malaysian tropical hardwood species:
Kedondong (Canarium spp), Bintangor (Calophyllum spp) and (Keruing (Dipterocarpus spp) for
tensile testing using the universal testing machine, which was done in accordance with ASTM
D198 procedures (tension along the grain). The properties measured included tensile strength,
strain and moisture content (was measured from the failed specimens). Results from the study
revealed that strain of all the three species was linearly correlated with stress (load) until failure.
The mean tensile strength of Kedondong, Bintangor and Keruing was found to be38.7 ± 6.2 MPa,
38.8 ±5.8 MPa and 41.2 ± 6.2 MPar respectively, which were higher than the theoretical values
given in MS 544: Part 2. This means that use of theoretical values could lead to over-designing
of structural timber components (bigger and more costly sections). The tensile strength results
also confirmed that the three species belong to the same strength group. Kedondong was found to
have the highest value of modulus of elasticity and Poisson’s ratio ( 13.4 ± 3.26 GPa∧0.63),
followed by Bintangor ( 11.9 ± 4.28 GPa∧0.60) while Keruing had the lowest value (
11.2 ± 4.25GPa∧0.54). Therefore these specimens are suitable for structural applications
because of their high tensile strength properties.

Eucalyptus Timber 17
Gilbert, et al. (2018) quantified the mechanical properties of three species of structural
timber: eucalyptus cloeziana (GMS), corymbia citriodora (SPG) and eucalyptus globulus (SBG),
across the grain. The species explored were obtained from juvenile subtropical hardwood logs
harvested from Australian forests. The authors conducted the study so as to establish if this
underutilized resource could be used as a structural construction material, which could
significantly increase its commercial value in Australia. The timber specimens were subjected to
different tests. The properties tested were compressive strength, tensile strength, shear modulus,
shear strength, modulus of elasticity, and rolling shear strength. Results obtained from the tests
showed that modulus of elasticity values recorded were in the range of 200 to 1300MPa; the
average compressive strength across the grain for SBG, GMS and SPG species was 4.7MPa,
7.9MPa and 8.4MPa respectively; the average shear strength across the grain for SBG, GMS and
SPG species was 6.8MPa, 7.5MPa and 8.4MPa respectively; tensile strength across the grain for
the species was 4-6 times less than their respective compressive strength across the grain;
whereas the average rolling shear strength for SBG, GMS and SPG species was 2.26MPa,
2.56MPa and 2.85MPa respectively. The results obtained showed weak to no correlation
between mechanical properties measured across the grain and the theoretical values of properties
parallel to the grain. Therefore when investigating the potential of timber for structural
applications, it is important to test the specimens of individual species so as to determine and
quantify their mechanical properties across the grain.
Franke & Quenneville (2011) examined the compression strength of New Zealand Radiata
Pine timber across the grain. This was after realizing lack of information about compression
strength values and complete performance of this timber species. The authors completed the
study by conducting compression tests that enabled them to measure compression strength values

Eucalyptus Timber 18
and examine the behaviour of the lumber species. They used different test standards, including
Australian/New Zealand standards (AS/NZS 4063:1992/2009) and International standards
(ASTM D143-09). A total of 150 specimens were tested for the three load cases. The theoretical
compression strength values used according to different test standards are as follows: European
standard - <3MPa, American and Canadian design standards – 3.1MPa-7.2MPa, and Australian
standard – 7MPa. On the other and, the mean compression strength (yield strength) and
maximum strength of the timber species obtained from the experiment were in the range of
6.2MPa-11.1MPa and 10MPa-34MPa respectively. The experimental results revealed that the
compression strength values of New Zealand softwood Radiata pine are very high compared to
the theoretical values being used. This has a significant effect on the design, behaviour, cost and
durability of structural timber components. The findings in the study showed that there is need to
conduct more research so as to provide up to date information on applicable compression
strength values of New Zealand softwood Radiata pine and update relevant standards being used.
Yang & Zhang (2018) presents an investigation of the mechanical properties of Korean pine
(Pinus koraiensis) so as to determine if it is suitable for use as an orthotropic material,
particularly in the restoration of conventional timber buildings. The investigation was done by
conducting laboratory tests on the timber specimens to measure tension strength, Poisson’s ratio,
coefficients of mutual influence, shear moduli and crushing strength. The authors found that
when the specimens were subjected to compression test in different grain directions, they
exhibited different failure modes. However, when the specimens were subjected to tension test
while loaded in varied grain directions, they only exhibited brittle failure pattern. A comparison
between experimental results and theoretical values estimated using theoretical formulas showed
significant similarities in terms of tensile and compressive properties. Therefore the authors

Eucalyptus Timber 19
concluded that the Korean pine qualifies to be used as a perfect orthotropic engineering material
for structural or construction applications.
Raposo, et al. (2017) carried out an experimental study to obtain the mechanical properties of
eucalyptus wood specimens from a 19th century masonry building. The specimens were obtained
from the roof structure of the building. The aim of the study was to use the data collected in
developing numerical models that can help in predicting the behaviour of structural wood
components and the wood structure as a whole. The authors performed the water content test,
density test, compressive test and tensile test to determine the water content, density,
compression strength and tensile strength respectively, parallel to or along the grains of the
wood. The average values of these properties as obtained from the experiment were as follows:
water content – 9.05%, density – 732 kg/m3, compression strength – 59.1MPa and tensile
strength – 65.5MPa. The authors noted that water content significantly influences the properties
and behaviour of wood because of expansion or retraction of the wood, and the resultant warping
and distortions that induces changes in the elastic modulus and strength of wood. However, the
water content has insignificant effect on the properties of wood if it is beyond the wood’s
saturation point. Bucking of wood when it is subjected to compression load also makes wood to
exhibit superior tensile strength than compressive strength. Therefore results from tensile and
compression tests can be used to predict the properties and performance of structural wood
materials.
da Silva, et al. (2013) present an investigation of thermally treated eucalyptus wood by
determining its chemical composition and also subjecting it to compression test along the grain
of the wood so as to measure the mechanical properties (stiffness and strength). After thermally
treating the wood specimens at a temperature ranging from 160°C to 240°C, the authors found

Eucalyptus Timber 20
that the mechanical properties and chemical components of the wood were significantly affected
by the thermal treatment process. The chemical contents of the wood included extractives
(reduced significantly), lignin (increased), holocellulose (degraded) and ashes (remained almost
the same). The thermal-rectification process reduced the strength of wood from 20% to 50% but
it increased the elasticity modulus by about 47%. However, the compression strength values
were lower than the typical values of Brazilian standard by nearly 23%. The results from the
study also revealed that the treatment temperature that provided optimum mechanical properties
was 180°C. The authors also developed a mathematical model that can be used to predict the
correlation between temperature and mechanical properties of wood.
Crespo, et al. (2016) compared the elastic constant values of Eucalyptus globulus obtained
from two different methodologies: mechanical compression tests and ultrasound tests. The same
wood samples that were used in the ultrasound tests were also used in the mechanical
compression tests. In mechanical compression testing, the tests were conducted in three
orientations: parallel, perpendicular and oblique to the grain of the wood. Generally, ultrasound
tests recorded higher elastic constant values than mechanical compression tests (especially when
tested parallel to the grain). The elastic constant values from the ultrasound tests were also the
closest to the theoretical values of other hardwoods. The results collected by the authors also
revealed that Eucalyptus globulus had superior properties than other hardwoods hence it is
potentially an ideal structural material for construction works.
Oh, et al. (2015) conducted a study to compare compressive strength values of lamina-
property based cross-laminated timber (CLT) estimated using a prediction model (best fit
Weibull distribution – a Monte Carlo simulation (MCS) model) and compression test. The main
aim of the study was to establish the accuracy and reliability of the prediction model for it to be

Eucalyptus Timber 21
used as an alternative to the experimental approach, which could be time-demanding and
expensive. Results obtained revealed that an increase in the number of lamina or wall length
caused an increase in the compressive strength of CLT panels. When estimating the 5th percentile
strength, MCS method was more accurate thus used in the study due to the underestimation
associated with deterministic method. The average compressive strength from the compression
tests was 47.93MPa while the 5th percentile strength from the prediction model was 38.36MPa.
The results also showed that a decrease in the width of the lamina caused an increase in the
compressive strength of the CLT panels. Therefore it is important to consider the effect of both
the length and width of the timber panels when examining their mechanical properties. The
authors concluded that there is need to carry out more research so as to develop reference design
values, CLT manufacturing and CLT wall design.
Fink & Kohler (2014) developed a prediction model for the tensile stiffness and tensile
strength of structural timber, considering its morphological characteristics (with and without
knots). The aim of the study was to develop a reliable prediction model and determine the effect
of knots on the mechanical properties of timber. Two sets of tests were conducted in the study:
non-destructive tensile tests and destructive tensile tests. Data collected from these tests was used
to develop models for predicting the tensile stiffness and tensile strength. The two models were
then compared with existing models for verification. Results from the study showed that data
collected from tensile tests can be used to develop models for predicting the material properties
(including tensile strength and tensile stiffness) of timber. The authors found larger correlations
(p = 0.953) between the predicted and measured stiffness properties. They also found a
correlation of p = 0.751 between the predicted and measured strength properties of the timber.
Another key finding from the study was that tensile strength of timber with knots should be taken

Eucalyptus Timber 22
as the corresponding value at the weakest knot section. Therefore the prediction model can be
useful in developing a more efficient grading criteria for timber.
Hein & Lima (2012) experimentally assessed the correlation between microfibril angle
(MFA) and modulus of elasticity (stiffness) and compressive strength of juvenile eucalyptus
wood. The aim of the study was to establish this correlation for the hardwood species so as to
determine if MFA has a significant influence on the mechanical properties of wood, which
affects its suitability for various uses. The MFA of the wood was measured using x-ray
diffraction method while compressive strength and modulus of elasticity was measured from
compression tests using an electromechanical universal testing machine. The wood properties
obtained from the tests (mean modulus of elasticity = 8,096MPa, mean MFA = 13.9° and mean
compressive strength = 51.17MPa) were similar to those found in several other similar studies.
The authors found a high correlation (0.91) between stiffness and compressive strength of the
eucalyptus wood. They also found that the correlation between MFA and wood stiffness and
compressive strength was -0.67 and -0.52 respectively. Results from the study showed that MFA
is an essential parameter that can be used as an indicator for strength and elastic properties and
the overall mechanical performance of eucalyptus wood.
Franke & Quenneville (2010) postulated that there was no data available on the in-depth
stress-strain behaviour, including multi-directional softening and hardening, for New Zealand
radiata pine. To fill this information gap, the others perform comprehensive compression tests in
accordance with different testing standards. They used varied loading configurations, including
multiple load-to-annual ring directions and load-to-grain angles (0° to 90°), and different
evaluation methods. The main parameters evaluated were proportional limit strength, tangent
modulus and modulus of elasticity. The results obtained from the compression tests showed that

Eucalyptus Timber 23
there was a strong correlation between load-to-grain direction and the compression behaviour of
the wood specimens, and the behavior was similar between the European spruce and radiata pine.
However, there was no correlation between annual ring direction and the behaviours across the
grain. Therefore compression parameters and behaviours of wood can be determined from the
compression tests.
Ehrhart, et al. (2018) estimated the tensile strength of European beech timber boards using a
recently developed non-contact approach and compared the results with those from typical
tensile tests. The new method is based on computerized visual examination of the spindle pattern
that is created by wood rays. In this approach, identification of the spindles is done by digital
techniques that extract image features of the wood, and determines the orientation and position
of these features. This information is then used to estimate tensile strength of the timber. The
authors measured the modulus of elasticity and density of the timber specimens and used the
values to estimate their tensile strength. The tensile tests carried out on the timber revealed that
tensile strength estimation by considering the local fiber orientation provides results that are
more accurate than estimation by considering other common indicators of stiffness and strength.
Thus the recently developed non-contact approach is reliable and can be used to improve the
strength grading of various timber species intended for structural applications.
Ritschel, et al. (2013) studied in detail the microscopic damage mechanism of solid wood and
laminated veneer lumber (LVL). This is typically the first step that researchers do to develop a
test technique for characterizing damage of wood elements. In their study, the authors performed
quasi-static tensile tests on the wood specimens and monitored the tests using digital image
correlation (DIC) and acoustic emission (AE). Results obtained from the tensile tests in the study
showed significant difference in tensile strength between solid wood and LVL. The different

Eucalyptus Timber 24
types of wood materials exhibited unique damage initiation and accumulation patterns that
resulted to macroscopic failure. The adhesive bonds, relative fiber orientation and the layered
structure of LVL affected the damage initiation and accumulation patterns in LVL. A simplified
plywood yielded earlier damage, followed by LVL and then solid wood. The authors concluded
that it is important to conduct tensile tests on each species of wood so as to understand its pattern
of damage and develop approach strategies of improving the performance of the wood for the
intended use.
Xu, et al. (2019) conducted an investigation on how elevated temperatures affect the
mechanical properties of laminated bamboo. The authors used steady-state test approach to
complete their study. The tensile-stress strain tests were conducted at temperatures ranging
between 20°C and 280°C. The results from the study revealed that an increase in temperature
reduces the elastic modulus, compressive strength and tensile strength of laminated bamboo, and
these parameters were similar in both edgewise and flatwise directions. Tensile failure of the
laminated bamboo was confirmed to be linear. The authors also proposed a formula for
describing the relationship between stress and strain of laminated mambo. Therefore information
from the study is useful in predicting the performance of laminated bamboo elements in elevated
temperature conditions, such as fire.
Mechanical properties of wood are influenced by a variety of factors, including defects of the
wood. Rocha, et al. (2018) presents a study on the effect of the size (small, medium and large) of
knots on the modulus of elasticity and compression resistance of eucalyptus wood. The study
was done by conducting compression tests on the wood specimens parallel to the grain. Results
obtained from the study showed a significant difference between the modulus of elasticity and
compressive strength of wood samples with smaller knots and the other wood samples with

Eucalyptus Timber 25
medium and larger knots. The results revealed that the difference between the modulus of
elasticity and compressive strength of the wood increased with the increase in the size of knots.
The authors also noted that the stiffness and strength values of wood samples with small knots
were nearly the same as those of wood with zero defects (defect free wood). The authors of the
study concluded the mechanical properties of eucalyptus wood are inversely related to the size of
the knots.
From the literature above, it is evident that there is great potential in using different species
of timber, including eucalyptus timber, as a structural construction material. However, the
mechanical properties of the wood must be determined first. Key of these properties are tensile
strength and compressive strength. Several studies have proved that tensile test and compression
tests are adequate in determining tensile and compressive properties of timber.
4. Limitations
One of the limitations, based on the above literature, is the impracticality of considering all
factors (such as defects, age, growth conditions, source, etc.) that affect the mechanical
properties of timber. The scope of the study limits the number of factors that are considered.
Failure to ensure that the directions are perfectly perpendicular or parallel to the grain is another
limitation. Sometimes it very challenging to be 100% perfect when aligning the test samples
parallel or perpendicular to the grain. Another limitation is that some tests are done at different
times or using equipment/machines that are in different rooms or locations. This has an effect on
the final results due to variations in test conditions and machine settings. The differences in the
test requirements, such as specifications and preparation of the specimens, laws and the
procedures followed, for the different test standards is another major limitation of the study.
Some of the studies are also limited by failing to achieve th exact specifications of the specimens

Eucalyptus Timber 26
as required in the test standards. As a result, the specifications of the specimens available end up
being used in the study, and are likely to give imprecise results. Lastly, some of the compression
and tensile test machines and approaches were recently developed and there is still lack of
adequate information about them, such as the precision or error margin and safety precautions.
This means that the researchers using these machines and approaches cannot guarantee the
accuracy of the results.
5. Summary
Timber has been used as a construction material for many decades and the increase demand
for this material has prompted more research on the potential of using other tree species in
structural applications. Eucalyptus timber is one of the commonest types of timber with a variety
of uses worldwide. It is a natural, renewable and sustainable material that has the capacity to
support design loads in a similar way as other conventional building materials, such as concrete,
steel, glass, plastic and composites. Several studies have found that there is great potential of
using eucalyptus timber in structural construction applications. Nevertheless, the suitability of
eucalyptus timber for structural applications should be backed by scientific data. This makes it
necessary to conduct relevant tests so as to measure and calculate values of various physical and
mechanical properties of eucalyptus timber. The tests should be carried out in accordance with
the applicable standards. The common tests performed are tensile test and compressive test. The
tests can be performed parallel to or perpendicular to the grain of timber. The test results
obtained in the past studies analyzed in the literature review have revealed that eucalyptus timber
has physical and mechanical properties that make it suitable for structural applications. Therefore
further research work is required to determine the exact tensile and compressive properties of
eucalyptus timber. This will confirm the suitability of using eucalyptus timber as a structural

Eucalyptus Timber 27
construction material and help meet the increasing demand of timber in Australia and other parts
of the world.

Eucalyptus Timber 28
References
Ahmad, Z., Bon, Y. & Wahab, E., 2010. Tensile strength properties of tropical hardwoods in structural
size testing. International Journal of Basic & Applied Sciences, 10(3), pp. 1-6.
Aigbomian, E. & Fan, M., 2013. Development of Wood-Crete from Hardwood and Softwood Sawdust.
The Open Construction and Building Technology Journal, 7(1), pp. 108-117.
Albaugh, J., Dye, P. & King, J., 2013. Eucalyptus and Water Use in South Africa. International Journal of
Forestry Research, 2013(1), pp. 1-11.
Antonsson, S., Makela, P., Fellers, C. & Lindstrom, M., 2009. Comparison of the physical properties of
hardwood and softwood pulps. Nordic Pulp and Paper Research Journal, 24(4), pp. 409-414.
Awan, A.R., Chughtai, M.I., Ashraf, M.Y., Mahmood, K., Rizwan, M., Akhtar, M., Siddiqui, M.T. & Khan,
R.A., 2012. Comparison for physico-mechanical properties of farm-grown eucalyptus camaldulensis
dehn. with conventional timbers. Pakistan Journal of Botany, 44(6), pp. 2067-2070.
Blackburn, D., Vega, M., Yong, R., Britton, D. & Nolan, G., 2018. Factors influencing the production of
structural plywood in Tasmania, Australia from Eucalyptus nitens rotary peeled veneer. South. For. J.
For. Sci., 1(1), pp. 1-10.
Cavalli, A., Cibecchini, D., Togni, M. & Sousa, H., 2016. A review on the mechanical properties of aged
wood and salvaged timber. Construction and Building Materials, 114(1), pp. 681-687.
Chen, J., 2017. Mechanical properties of laminated veneer lumber (LVL) produced from eucalyptus
nitens. Hobart: University of Tasmania.
Crespo, J., Aira, J.R., Vazquez, C., Majano-Majano, A. & Guaita, M., 2016. Determination of the elastic
constants in eucalyptus globulus by ultrasound and mechanical tests. Vienna, World Conference on
Timber Engineering.
da Silva, M., Machado, G., Brito, J. & Calil Jr., C., 2013. Strength and Stiffness of Thermally Rectified
Eucalyptus Wood Under Compression. Materials Research, 16(5), pp. 1077-1083.
Derikvand, M., Kotlarewski, N., Lee, M., Jiao, H. & Nolan, G., 2019. Characterisation of physical and
mechanical properties of unthinned and unpruned plantation-grown Eucalyptus nitens H.Deane &
Maiden lumber. Forests, 10(194), pp. 1-13.
Derikvand, M., Nolan, G., Jiao, H. & Kotlarewski, N., 2017. What to Do with Structurally Low-GradeWood
from Australia’s Plantation Eucalyptus; Building Application?. BioResources, 12(1), pp. 4-7.
Diffen, 2013. Hardwood vs. Softwood. [Online]
Available at: https://www.diffen.com/difference/Hardwood_vs_Softwood
[Accessed 10 October 2019].
Ehrhart, T., Steiger, R., Palma, P. & Frangi, A., 2018. Estimation of the tensile strength of European beech
timber boards based on density, dynamic modulus of elasticity and local fibre orientation. Seoul, 2018
World Conference on Timber Engineering.
Fink, G. & Kohler, J., 2014. Model for the prediction of the tensile strength and tensile stiffness of knot
cluasters within structural timber. Eur. J. Wood Prod., 72(1), pp. 331-341.

Eucalyptus Timber 29
Foster, R., Ramage, M., Smith, S., Flanagan, K. & Bakker, R., 2017. Super Tall Timber: design research for
the next generation of natural structure. The Journal of Architecture, 22(1), pp. 104-122.
Franke, S. & Quenneville, P., 2010. The material behaviour of radiata pine under compression. New
Zealand Timber Design Journal, 18(3), pp. 13-18.
Franke, S. & Quenneville, P., 2011. Compression Strength Perpendicular to the Grain of New Zealand
Radiata Pine Lumber. Australian Journal of Structural Engineering, 12(1), pp. 1-12.
Gilbert, B.P., Husson, J.M., Bailleres, H., McGavin, R.L. & Fischer, M.F., 2018. Perpendicular to grain and
shear mechanical properties of veneer-based elements glued from single veneer sheets recovered from
three species of juvenile subtropical hardwood plantation logs. European Journal of Wood and Wood
Products, 76(1), pp. 1637-1652.
Hein, P. & Brancheriau, L., 2018. Comparison between three-point and four-point flexural tests to
determine wood strength of Eucalyptus specimens. Wood: Science and Technology, 20(3), pp. 333-342.
Hein, P. & Lima, J., 2012. Relationship between microfibril angle, modulus of elasticity and compressive
strength in eucalyptus wood. Maderas Ciencia tecnologia, 14(3), pp. 267-274.
Kremer, P. & Symmons, M., 2015. Mass timber construction as an alternative to concrete and steel in
the Australia building industry: A PESTEL evaluation of the potential. International Wood Products, 6(3),
pp. 138-147.
Lahr, F.A.R., Nogueira, M.C., Araujo, V.A., Vasconcelos, J.S. & Christoforo, A.L., 2018. Wood utilization of
Eucalyptus grandis in structural elements: densities and mechanical properties. Eng. Agríc., 38(5), pp.
642-647.
Liao, Y., Tu, D., Zhou, H., Yun, H., Gu, J. & Hu, C., 2017. Feasibility of manufacturing cross-laminated
timber using fast-grown small diameter eucalyptus lumbers. Construction Building Materials, 132(1), pp.
508-515.
Lima Jr, M. P., Biazzon, J. C., De Araujo, V. A., Munis, R. A., Martins, J. C., Cortez-Barbosa, J., Gava, M.,
Valarelli, I. D. & Morales, E. A. M., 2018. Mechanical properties evaluation of Eucalyptus grandis wood at
three different heights by impulse excitation technique (IET). BioResources, 13(2), pp. 3377-3385.
Malone, B., Gupta, R., Miller, T. & Puettmann, M., 2014. Environmental impact assessment of light-
frame and timber frame. Journal of Green Building, 9(2), pp. 102-123.
Manriquez, M. & Moraes, P., 2010. Influence of the temperature on the compression strength parallel to
grain of paricá. Construction and Building Materials, 24(1), pp. 99-104.
Moshtaghin, A., Franke, S., Keller, T. & Vassilopoulos, A., 2016. Experimental characterization of
longitudinal mechanical properties of clear timber: Random spatial variability and size effects.
Construction and Building Materials, 120(1), pp. 432-441.
Mou, S., (n.d.). Properties of timber - qualities of good timber and wood. [Online]
Available at: https://civiltoday.com/civil-engineering-materials/timber/182-properties-of-timber
[Accessed 10 October 2019].

Eucalyptus Timber 30
Naylor, A., Hackney, P. & Perera, N., 2012. Determination of wood strength properties through standard
test procedures. Birmingham, UK, Tenth International Conference on Manufacturing Research.
Nogueira, M.C.A., de Almeida, D.H., De Araujo, V., Vasconcelos, J., Christofor, A.L., de Almeida, T.H. &
Lahr, F.A.R., 2019. Physical and Mechanical Properties of Eucalyptus saligna Wood for Timber Structures.
Environment Constructed, 19(2), pp. 233-239.
Oh, J., Lee, J. & Hong, J., 2015. Prediction of compressive strength of cross-laminated timber panel. J.
Wood Sci, 61(1), pp. 28-34.
Oh, S., 2011. Applying failure criteria to the strength evaluation of 3-ply laminated veneer lumber
according to grain direction by uniaxial tension test. Construction and Building Materials, 25(3), pp.
1480-1484.
Quartucci, F., Schweier, J. & Jaeger, D., 2015. Environmental analysis of Eucalyptus timber production
from short rotation forestry in Brazil. International Journal of Forest Engineering, 26(3), pp. 1-15.
Ramage, M.H., Burridge, H., Busse-Wicher, M., Fereday, G., Rynolds, T., Shar, D.U., Wu, G. & Yu, L., 2017.
The wood from the trees: The use of timber in construction. Renewable and Sustainable Energy
Reviews, 68(1), pp. 333-359.
Raposo, P.C., Correia, J.A.F.O., Sousa, D., Salavessa, M.E., Reis, C., Oliveira, C. & de Jesus, A., 2017.
Mechanical properties of wood construction materials from a building from the 19th century. Procedia
Structural Integrity, 5(1), pp. 1097-1101.
Ravenshorst, G., 2015. Species independent strength grading of structural timber. Delft, Netherlands:
Delft University of Technology.
Reyes-Rivera, J., Canché-Escamilla, G., Soto-Hernández, M. & Terrazas, T., 2015. (2015) Wood Chemical
Composition in Species of Cactaceae: The Relationship between Lignification and Stem Morphology.
PLoS ONE, 10(4), pp. 1-10.
Ritschel, F., Brunner, A. & Niemz, P., 2013. Nondestructive evaluation of damage accumulation in tensile
test specimens made from solid wood and layered wood materials. Composite Structures, 95(1), pp. 44-
52.
Rocha, M.F.V., Costa, L.R., Costa, L.J., de Araujo, A.C.C., Soares, B.C.D. & Hein, P.R.G, 2018. Wood knots
influence the modulus of elasticity and resistance to compression. Wood Science and Technology, 25(4),
pp. 1-6.
Shanbhaq, R. & Sundararaj, R., 2013. Physical and Chemical Properties of Some Imported Woods and
their Degradation by Termites. Journal of Insect Science, 13(63), pp. 1-8.
Song, Y. & Zhang, H., 2018. Research on sustainability of building materials. IOP Conference Series:
Materials Science and Engineering, 452(1), pp. 1-4.
Vecchio, M., Loganes, C. & Minto, C., 2016. Beneficial and Healthy Properties of Eucalyptus Plants: A
Great Potential Use. The Open Agriculture Journal, 10(1), pp. 52-57.
Xu, M., Cui, Z., Tu, L., Xia, Q. & Chen, Z., 2019. The effect of elevated temperatures on the mechanical
properties of laminated bamboo. Construction and Building Materials, 226(1), pp. 32-43.

Eucalyptus Timber 31
Yang, N. & Zhang, L., 2018. Investigation of elastic constants and ultimate strengths of Korean pine from
compression and tension tests. Journal of Wood Science, 64(1), pp. 85-96.
Zabihi, H., Habib, F. & Mirsaeedie, L., 2012. Sustainability in Building and Construction: Revising
Definitions and Concepts. International Journal of Emerging Sciences, 2(4), pp. 570-578.