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INVESTIGATION INTO THE PROPERTIES OF LONG-SPAN ALUMINIUM ROOFING MATERIALS USED IN CONSTRUCTION INDUSTRIES IN NIGERIA

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The paper presents the results of experimental investigation on the properties of Aluminum long-span roofing sheets used in building construction in Nigeria. The determination of the properties was done in accordance with ASTM E-466(2000) and NIS 488(2004) using specimens manufactured by three most common aluminum roof material producers in Nigeria. The three most common gauges: 0.45, 0.55 and 0.70 were chosen for the investigation. The results of the tests revealed that the tensile strength, flexural strength and the impact resistance properties increase as the thickness of the aluminum sheet materials increases. The specific gravity of the specimens, also, increases with the thickness of the materials. These results are in consistency with the ASTM standard. It is also evident from the results that the specimen gauge of 0.45 failed to meet the ASTM E-466 and NIS 488 standards for all the variants of the roofing sheets. It is therefore recommended that 0.55 gauge should be the minimum thickness for structural aluminum roofing sheets in the Nigerian building industry.
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JOURNAL OF ENGINEERING AND TECHNOLOGY (JET), VOL.5 NO.2, AUGUST, 2010
INVESTIGATION INTO THE PROPERTIES OF LONG-SPAN ALUMINIUM
ROOFING MATERIALS USED IN CONSTRUCTION INDUSTRIES IN NIGERIA
+Uche, O.A.U and Oyedipe, A.K.
Civil Engineering Department, Bayero University, Kano, P.M.B 3011, Kano, Nigeria
+Email: OKOAUCHE@yahoo.co.uk
ABSTRACT
The paper presents the results of experimental investigation on the properties of Aluminum long-span roofing
sheets used in building construction in Nigeria. The determination of the properties was done in accordance
with ASTM E-466(2000) and NIS 488(2004) using specimens manufactured by three most common aluminum
roof material producers in Nigeria. The three most common gauges: 0.45, 0.55 and 0.70 were chosen for the
investigation. The results of the tests revealed that the tensile strength, flexural strength and the impact
resistance properties increase as the thickness of the aluminum sheet materials increases. The specific gravity
of the specimens, also, increases with the thickness of the materials. These results are in consistency with the
ASTM standard. It is also evident from the results that the specimen gauge of 0.45 failed to meet the ASTM E-
466 and NIS 488 standards for all the variants of the roofing sheets. It is therefore recommended that 0.55
gauge should be the minimum thickness for structural aluminum roofing sheets in the Nigerian building
industry.
1.0 INTRODUCTION
Long-span Aluminum roofing products have
been discovered lately to be largely replacing
other roof covering materials such as asbestos,
clay tiles, concrete, asphalt shingles, etc. in
construction industry in Nigeria. This
particular trend in building industry has led to
importation of different variants of this
material. Aluminum roofs come in a great
variety of beautiful colours designed to accent
the style and add grace to our homes. Earlier
report in Roofing Directory (2008) reveals that
aluminum roofing material is one of the most
common metal roofing materials widely used
in roof industry across the world. This wide
acceptance may not be unconnected with its
properties that were reported by Baker (1984)
and Smith (2008) which include strength,
lightweight, rust resistance and attractive
posture. Its numerous benefits include
durability, easy installation, easy to work with
and lightweight, energy efficiency and rust
resistance among others.
Premature structural roof collapses have been
recorded in building industry as a result of the
use of less than adequate roofing materials for
the environment to which the roof is exposed.
For instance, asphalt shingle roof is reported to
start losing its protective properties once it
becomes exposed to the action of sun, wind,
snow, rain and ice. Also Aluminum roofing
materials have been preferred to steel
galvanized roof materials in coastal areas
where heightened concentration of salt in the
environment can make the steel materials
susceptible to corrosion over the time (Smith,
2008). In choosing an appropriate roof
material, it is necessary to consider economy,
quality, aesthetics, as well as application and
service life. Most materials used today in
Nigeria roof industry are factory finished
sheets referred to as prefabricated roofing
sheets (Queensway Aluminum, 2007). Some
appear of much higher quality while some are
easily punctured, cut-burnt or deteriorated by
common contaminants. The performance
behaviour of many variants of the long span
aluminum roof materials used in roof industry
in Nigeria has elicited the investigation into
the properties of the materials
Uche, O.A.U. and Oyedipe, A.K.
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JOURNAL OF ENGINEERING AND TECHNOLOGY (JET), VOL.5 NO.2, AUGUST, 2010
2.0 MATERIALS AND METHODS
2.1 Materials: There are various types of
long-span Aluminum roofing products used in
Nigerian construction industry. These products
can be analysed based on their profiles,
Gauges (thickness), colours, flashings and
other fixtures. Samples of Aluminum material
used for the tests were obtained from three
Longspan Aluminum manufacturing
companies namely; Queensway Aluminum
company Ltd, Kaduna; First Aluminum Ltd,
Port-Harcourt and Qualitec Aluminum Ltd,
Abuja. The materials were obtained in three
common thickness variants of 0.45mm,
0.55mm and 0.70mm gauges.
2.2 Methods: Tensile strength, flexural
strength, specific gravity, impact resistance
and weather resistance tests were carried out in
accordance with the relevant standards on at
least three samples of each variant thickness
for each identified manufacturer.
2.2.1 Tensile strength test. The tensile
strength test was carried out in accordance
with ASTM E-466: 2000. A 50mm x 150mm
sized specimen was loaded destructively using
Makewa universal testing machine of 98.07kN
capacity. Load was applied at rate of
7.84N/mm per second until the specimen
failed in tension. The test was repeated for all
the selected samples and average values taken.
The result is as presented in Table 1.
Table 1: Tensile Strength of Longspan Aluminum Roofing Sheets Tested.
Manufacturer
Profile Thickness
(mm)
Load
(kN)
Average Tensile
Strength (N/mm2)
First Aluminum
0.45
0.63
28.00
0.55
1.30
47.00
0.70
2.52
72.00
Qualitec
Aluminum
0.45
0.60
27.00
0.55
1.10
40.00
0.70
2.35
67.00
QueensWay
Aluminum
0.45
0.65
29.00
0.55
1.35
49.00
0.70
2.70
77.00
2.2.2 Flexural Strength Test. The
compressive strength test was also carried out
in accordance with ASTM E- 34: 2000 and
NIS 488:2004. The same sized specimen was
tested using simple compression equipment
with magnifiers as the free end was bent to
angle of 90o in a smooth and uniform manner.
The operation continued until the bent end
completes a 180o bend. The bent specimen was
then examined for possible cracks using lens
or low power microscope. The results on the
three thickness variant of the manufacturing
company as test are shown in Table 2.
Table 2: Specific Gravity of Longspan Aluminum Roofing Sheets Tested
Profile Thickness
(mm)
Observations
First
Aluminum
0.45
Minor Cracks
0.55
No Cracks
0.70
No Cracks
Qualitec
Aluminum
0.45
Visible Cracks
0.55
Minor Cracks
0.70
No Cracks
QueensWay
Aluminum
0.45
Minor Cracks
0.55
No Cracks
0.70
No Cracks
Uche, O.A.U. and Oyedipe, A.K.
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JOURNAL OF ENGINEERING AND TECHNOLOGY (JET), VOL.5 NO.2, AUGUST, 2010
2.2.3 Specific Gravity Test. The test was
conducted in accordance with the Archimedes
principles using the pyconmeter bottle. The
result is as shown in Table 2.
2.2.4 Impact and Weather Resistance Test.
Impact and Weather Resistance tests were
conducted in accordance with NIS 487:2004
using rapid deformation, ultra violet ray light,
oxygen and water. The specimen used was
100mm x 200mm in size for both tests. The
test results are as shown in Tables 3.
Table 3: Impact and Weather Resistance of Long span Aluminum Roofing Sheets Tested
Specimen
Profile
Thickness
(mm)
Impact Resistance
on 14mm punch size
Weather Resistance
Corrosion
Fungi growth
First
Aluminum
0.45
Slight crack(4.6mmØ)
Free
No Attack
0.55
No Crack
0.70
No Crack
Qualitec
Aluminum
0.45
Visible Crack(10mmØ)
Free
No Attack
0.55
Slight Crack(5mm Ø)
0.70
No Crack
QueensWay
Aluminum
0.45
Slight crack (3mm Ø)
Free
No Attack
0.55
No Crack
0.70
No Crack
3.0 ANALYSIS AND DISCUSSION
3.1 Tensile Strength: The result of the tensile
strength shown in Table 1 showed that the
tensile strength increases as the thickness of
the various long-span Aluminum increases.
When compared to provision of the ASTM
standard which provided for 49N/mm2 as the
minimum tensile strength, it is evident that the
thickness range of 0.45mm is unsatisfactory
for all the variants of the long-span Aluminum
tested. Also the 0.55mm thick products of
First Aluminum and Qualitec Aluminum
barely satisfied the minimum standard leaving
only the 0.55mm of QueensWay Aluminum
and 0.70mm thick products of all the
Aluminum samples as satisfactory. According
to NIS 488: 2004, the minimum prescribed
standard thickness is 0.55mm. Any thickness
less than this specified are easily susceptible to
leakages and discolouration due to corrosion
and tear. The variations in tensile strength may
be as a result of production variants in the
material properties. This is also depicted as in
Figure 1.
3.2 Flexural Strength: According to NIS
488:2004 the Flexural strength of the
aluminum materials is its ability to resist
cracks or deformation when subjected to 180o
bend test. A comparison of compressive
strength results of the three products tested in
Table 2 shows that visible to minor cracks
were observed in the 0.45mm thickness variant
for all the products. Whereas Qualitect
Aluminum brand of 0.55mm thickness still
displayed evidence of failure in bending with
minor crack, the 0.55mm thickness brands for
First Aluminum and Qweensway proved
satisfactory in bending. All the brands with
0.70mm thickness satisfied the bending stress
test.
3.3 Specific Gravity: The results shown in
Table 2 reveal that Specific Gravity increases
as the thickness increases. All the values
obtained in the tests are within the
recommended values in the code.
Uche, O.A.U. and Oyedipe, A.K.
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JOURNAL OF ENGINEERING AND TECHNOLOGY (JET), VOL.5 NO.2, AUGUST, 2010
3.4 Impact and Weather Resistance: The
Impact and Weather resistance test results
presented in Table 3 showed that the
Aluminum brands displayed these same results
as in bending stress test. Whereas the 0.45mm
thickness failed impact tests for all brands, the
0.70mm thickness was satisfactory. Qualitec
brand was adjudged weakest as its 0.55mm
thick brand still failed the impact test. The
results also indicate that all the Aluminum
brands satisfied the weather resistance test in
respective of the thickness variants. It shows
that all the brands contain Aluminum Oxide’s
coating which provide resistant to attack by
the environment. This simply implies that all
the Aluminum brands are basically sound in
terms of colours coated on them as they will
stay many years without discolouring.
Figure 1: Tensile Strength of Long-span Aluminum Roofing sheets used in Construction Works in
Nigeria
4.0 CONCLUSION
The results of the investigation into the
properties of some long-span Aluminum
roofing materials used in construction industry
in Nigeria has been presented. The following
conclusions are hereby made.
1. The strength of Aluminum roofing
material increases with increase in
thickness of the variants, which conforms
with facts established in the literature.
2. The tests on the common thickness
variants of 0.45mm, 0.55mm and 0.70mm
showed that long-span roof materials of
0.45mm thickness failed all standard
specifications of tensile, bending stresses
and impact resistance test.
3. All the long span roof materials tested
passed the specifications on weather
resistance as there were no corrosion or
fungi attack on the materials.
4. The quality grade of the three sample
variants showed that Queenways
Aluminum rates highest. This is followed
0
10
20
30
40
50
60
70
80
90
0.45
0.55
0.7
Tensile Strength (N/mm2)
Product Thickness (mm)
Qualitec
FIRST ALU
QUEENS
STD SPEC
Uche, O.A.U. and Oyedipe, A.K.
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JOURNAL OF ENGINEERING AND TECHNOLOGY (JET), VOL.5 NO.2, AUGUST, 2010
by First Aluminum and then Qualitec
Aluminum.
5. It is recommended that 0.45mm thick of
any long-span Aluminum products
employed in roof work in Nigerian
construction industry should be
discontinued.
5.0 REFERENCES
ASTM D-466(2000): Aluminum Material
Testing, ASTM International Corporation West
Conshohocken, U.S.A
Baker, M.C (1984): New Roofing Material,
Canadian Digest, Ottawa Canada
NIS 488(2004): Nigerian Industrial
Standards’ Test Methods for Profile Aluminum
Roofing Sheet, Standard Organisation of Nigeria
Publications, Lagos Nigeria.
Queensway Aluminum Co. Ltd (2007):
Complete Roofing Systems, Manufacturers’
Catalogue, Kaduna Nigeria
Smith, S.E (2008): What is Aluminum;
Conjecture Corporation, Sparks NV432, U.S.A.
Roofing Directory (2008): Roofing Industry
Practices, Directory of Roof Contractors;
www.roofingdirectory.com. Retrieved 6/09/2009
Uche, O.A.U. and Oyedipe, A.K.
108
ResearchGate has not been able to resolve any citations for this publication.
New Roofing Material, Canadian Digest
  • M Baker
Baker, M.C (1984): New Roofing Material, Canadian Digest, Ottawa Canada NIS 488(2004): Nigerian Industrial Standards' Test Methods for Profile Aluminum Roofing Sheet, Standard Organisation of Nigeria Publications, Lagos Nigeria. Queensway Aluminum Co. Ltd (2007):