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International Journal of Civil Engineering and Technology (IJCIET)
Volume 10, Issue 10, October 2019, pp. 356-367, Article ID: IJCIET_10_10_035
Available online at http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=10&IType=10
ISSN Print: 0976-6308 and ISSN Online: 0976-6316
© IAEME Publication
EFFECT OF PARTIAL REPLACEMENT OF
COARSE AGGREGATE BY CRUSHED BROKEN
GLASS ON PROPERTIES OF CONCRETE
Onyeka, F. C
Department of Edo University, Iyamho, Edo State.
Email: [email protected]
ABSTRACT
The importance of coarse aggregate in concrete cannot be overemphasized. Glass
forms a major component of solid waste in many countries and can be recycled after
use. Although, small proportion used by consumers has been recycled and reuse while
about 70-80% is disposed in the landfill and this constitutes to environmental waste.
This work investigated the suitability of glass as a partial replacement of conventional
aggregate (crushed granite) in the production of concrete. The concrete was produced
with coarse aggregates and were replaced by glass at 15%, 25%, 35% and 45% using
a mix ratio of 1:2:4 with a water cement ratio of 0.6. Several tests were carried out
ranging from aggregate to fresh and hardened concrete test. It was observed that the
specific gravity of the glass was lower than that of granite was causing a reduction in
the densities of the concrete. Workability of the concrete increased with the increase
in the glass content which is indicated by the result of the slump test which gave 5mm,
10mm, 20mm, 40mm and 45mm for the 0%, 15%, 25%, 35% and 45% replacements.
Reduction of the strength of the concrete increased at the increase in the percentage of
the glass. The compressive strength of concrete with 100% granite at 28 days is
26N/mm2, while that of concrete gave 25.04 N/mm
2 strengths, 24.37N/mm
2, 22.22
N/mm2 and 21.55N/mm
2, for 15%, 25%, 35% and 45% replacement of granite with
glass respectively. Concrete up to 20 N/mm2 strengths can be used for structural work.
Therefore, it is recommended that aggregates can be replaced up to 45%, but 15% is
not recommended.
Keywords: Coarse Aggregate, Crushed Granite, Concrete Performance, Partial
replacement, Broken Glass
Cite this Article: Onyeka, F. C, Effect of Partial Replacement of Coarse Aggregate
by Crushed Broken Glass on Properties of Concrete. International Journal of Civil
Engineering and Technology 10(10), 2019, pp. 356-367.
http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=10&IType=10
Effect of Partial Replacement of Coarse Aggregate by Crushed Broken Glass on Properties of
Concrete
http://www.iaeme.com/IJCIET/index.asp 357 [email protected]
1. INTRODUCTION
Concrete is a composite material which comprises primarily of cement, the water's fine and
coarse aggregates. The coarse aggregates which are generally crushed rocks with sizes bigger
than 4.75mm while fine aggregates are basically sand which could be obtained from land or
water and their particle size should be less than 4.75mm. Increasing cost of these materials
has greatly hindered the development of shelter and other infrastructural facilities in Nigeria
and other developing countries. There arises the need for engineering consideration of the use
of cheaper and locally available materials to meet desired needs, enhance self-efficiency, and
lead to an overall reduction in construction cost for sustainable development.
One of the major problems of developing countries is improper management of the vast
amount of waste generated by various human activities (Robert, 2012). Quantities of waste
glass and steel wastes have been on the rise in recent years due to an increase in
industrialization and the rapid improvement in the standard of living. Unfortunately, the
majority of waste glass and steel wastes are is not being recycled, but rather abandoned and is,
therefore, the cause of serious problems such as waste of natural resources and environmental
problem. Some of the non-degradable waste, of which glass is included cannot be properly
disposed, except by recycling them and the limited number of properly constructed landfills in
Nigeria has made the disposal of the waste a serious challenge. Landfills do not constitute an
environmental solution to the disposal of non-degradable waste (EsraaEmam and Sherif,
2012).
Use of waste material as aggregates in civil engineering applications is beneficial because
it reduces the environmental impact and economic cost of quarrying operations, processing,
and transportation. According to Khatib et al., 2012, the energy required to reuse the
recyclable material is less than that of virgin materials. Over the years several attempts has
been made by researchers to use waste materials in the production of concrete and some of the
materials used includes sawdust, fly ash, fuel ash palm kernel shells, periwinkle shell, glass
etc. This has in great measure catered for the problem which could result from improper
disposal of the waste and the cost of disposal.
Since the demand of concrete in the construction industry is increasing day by day, this
study has a lot of significance in the assessment of the performance of concrete with partial
replacement of coarse aggregate with crushed broken glass. The use of crushed, broken glass
as coarse aggregate greatly enhances the aesthetic appeal of the concrete. The results from this
study will be useful and serve as a guide in knowing the percentage of glass replacement that
will achieve optimum compressive and flexural strength in the production of concrete using
glass in partial replacement of coarse aggregate.
The economic recession has led to the increase in prices of materials used in production of
concrete, which invariably impact on the rate at which infrastructural development take place
in the country.
Shelter which arguably the most important need of man has been jeopardised by this
problem as about seven million are without shelter according Punch (2012). This study is
timely as it is meant to address the present housing problem in Nigeria through the use of
waste materials which would have caused harm to the society.
Recent research findings have shown that concrete made with recycled glass aggregate
has shown better long term strength and better thermal insulation due to the better thermal
properties of the glass aggregates. Recycled glass as aggregate can also greatly enhance the
aesthetic appeal of the concrete. Glass is a unique inert material that could be recycled many
times without changing its chemical properties. The major aim of environmental authorities is
Onyeka, F. C
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to reduce, as far as possible, the disposal of postconsumer glass in landfill and diversion to
economically viable glass product is a great gain.
However, review study by Rashed (2014) showed that previous studies with glass addition
were not conclusive considering workability and strength while the chloride resistance of
glass added concrete was found to be similar with control condition. Therefore, this study will
examine critically the strength properties of concrete whose coarse aggregate is partially
replaced with glass.
The aim of this study is to assess the performance of concrete with partial replacement of
coarse aggregates with crushed broken glass. The specific objectives of the study are as
follows:
To design a concrete mixes using crushed glass products waste chips as aggregates
To ascertain compressive strength of concrete mode using glass waste as partial replacement
of coarse aggregate
To ascertain workability of concrete mode using glass product waste chip as partial
replacement of coarse aggregate
To compare the performance of conventional concrete and concrete produced with crushed
glass waste as coarse aggregate.
To determine the optimum percentage at which coarse aggregate can be replaced by crushed
glass waste chips
2. MATERIALS AND METHODOLOGY
2.1. Materials
In conducting the experimental studies in the laboratory to determine the performance of
concrete with partial replacement of coarse aggregate with crushed broken glass, the
following materials are used; Ordinary Portland Cement, Natural Fine Aggregate, Coarse
Glass Aggregate, Coarse Aggregate and Water.
2.2. Cement
The cement that will be used for this is Ordinary Portland Cement (Grade 42.5). Sourced from
Dangote Cement Plc., Obajana plant and it conformed to the requirement of BS 12, 1996. The
cement will be checked to ascertain that it is lump and cake free.
Table 1 Chemical Composition of Ordinary Portland Cement (Mtallib, 2009).
Name of Compound Oxide Composition Trade Name
Dicalcium Silicate 2CaO.SiO2 C2S
Tricalcium Silicate 3CaO.SiO3 C3S
Tricalcium Aluminate 2CaOAl2O3 C3A
TetracalciumAlumino-ferrita 4CaOAl2O3Fe2O3 C4AF
2.3. Fine Aggregate
Fine aggregates used in this study comprised of clean river sand with maximum size of
4.75mm obtained Ovim River in Isuikwuato Local Government Area of Abia State and the
impurities were flushed with water to reduce the level of impurities and organic matter and
latter sun dried to conformed to the requirements of BS 882 (1992).
Effect of Partial Replacement of Coarse Aggregate by Crushed Broken Glass on Properties of
Concrete
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2.4. Coarse Aggregate
The coarse aggregate used for this study is granite. The granite (coarse aggregate) used for the
study will be 20mm diameter in size. It will be sourced from a quarry site at Umunneochi
LGA Abia State Nigeria. And it will be washed to remove impurities from it.
2.5. Coarse Glass Aggregate
Waste glass materials used throughout this study were gathered from the disposal of
reconstruction and building demolishing projects. These materials were primarily originated
from pure and clear glass windows. The whole quantity was cleaned out of the dirt materials
and impurities, and then crushed manually and sieved.
2.6. Water
In accordance with BS 3148, Potable water was used for mixing the concrete mix in the entire
investigation and for curing the concrete in finding the performance of concrete with partial
replacement of coarse aggregate with crushed broken glass.
Table 2 Summary of the design for Concrete Cube (Compressive Strength)
Percentage of
Glass chips
Water (m3) Cement (Kg) Sand (Kg) Broken glass
chips (Kg)
Coarse Aggregate
(Kg)
0%GC 6.40 10.66 21.23 0.00 42.63
15%GC 6.40 10.66 21.23 6.39 36.24
25%GC 6.40 10.66 21.23 10.66 31.97
35%GC 6.40 10.66 21.23 14.92 27.71
45%GC 6.40 10.66 21.23 19.18 23.45
2.7. Testing Method
The test will be carried out in three phases which includes Aggregate test, Fresh concrete test,
Hardened concrete test.
The test that will carried out on the samples are summarized as follows; they are the test
on the aggregates to determine its suitability as materials to be used for the test, then the test
on the fresh and hard concrete will also be carried.. Finally a comparative analysis will be
made on the result obtained when using glass as the coarse aggregate or granite only.
Onyeka, F. C
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2.8. Summary of the Methodology for the Study
Figure 1 Flow chart showing the processes involved in the study
3. PRESENTATION, ANALYSIS OF RESULT AND DISCUSSION
3.1. Particle Size Distribution Analysis for Aggregates:
Sieve analysis with respect with material (Sand, Aggregate and Cement) weight and specific
gravity was performed in accordance with BS 1377: PART 2:1990 specification.
From results in figures 2, 3 and 4, the uniformity coefficient and fineness modulus
calculated.
Uniformity coefficient Cu:
For sand D60= 0.6, D10= 0.45, D30=0.52
Cu=
=
= 1.3333; Cc=
=
= 1.0015
COMPARISON AND ANALYSIS OF RESULT and
SPECIMEN
START
DESK STUDY
MIXING EXPERIMENT PROCESS
(CONCRETE SAMPLE)
MIXING EXPERIMENT PROCESS OF
GLASS CONCRETE
EVALUATION
OF MIXTURE
EVALUATION
OF MIXTURE
CASTING OF THE CONCRETE
CUBES
CURING PROCESS
FOR 7, 14, 21, 28 DAYS CASTING OF THE CONCRETE CUBE
TEST ON THE HARD
CONCRETE
Effect of Partial Replacement of Coarse Aggregate by Crushed Broken Glass on Properties of
Concrete
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The uniformity coefficient Cu and the coefficient of curvature Cc for sand is 1.3333 and
1.0015 respectively. From the following result which has values within the range for well
graded aggregate with Cu less than 4 and Cc within (1-3) for soil required for concrete.
Figure 2 Particle Size distribution Graph of Sand
Figure 3 Particle Size distribution Graph of Coarse Glass Aggregate
Figure 4 Particle Size distribution Graph of Coarse Aggregate
Onyeka, F. C
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3.2. Specific Gravity of Aggregates
The specific gravity of Sand, Coarse Aggregate and Glass Coarse Aggregate and Dangote
Cement (to determine on relative paraffin value for the OPC (Dangote) was carried out at
room temp thus yielding the following results.
Table 3 Specific Gravity of Sand
DESCRIPTION SAMPLE A SAMPLE B
Weight of pyconometer bottle (W1) (g) 618.7 618.7
Weight of Pyconometer bottle + sample (W2)
(g)
1023.9 1054.3
Weight of Pyconometer + sample + water (W3)
(g)
1704.9 1749.0
Weight of Pyconometer + water (W4) (g) 1493.0 1493.0
P=
= 2.1
=
2.42
Average specific gravity 2.26
Table 4 Specific Gravity of Coarse Aggregate and Water Absorption
Table 5 Specific Gravity of Glass Coarse Aggregate
DESCRIPTION SAMPLE A SAMPLE B
Weight of pyconometer bottle (W1) (g) 618.7 618.7
Weight of Pyconometer bottle + sample (W2) (g) 995.5 990
Weight of Pyconometer + sample + water (W3) (g) 1700 1695.5
Weight of Pyconometer + water (W4) (g) 1493.0 1493.0
P=
=
2.2293
= 1.996
Average specific gravity 1.8584
DESCRIPTION SAMPLE A SAMPLE B
Mass of Air Dried Sample (A) 2266.2 2312.5
Mass of Basket + Sample in Water (B)(g) 1566.7 1595.2
Mass of Basket in Water (C) (g) 244.6 244.6
Mass of Oven Dried Sample (D) (g) 2212 2303
P=
= 2.40
= 2.404
Average Specific Gravity 2.402
Water Absorption =
= 2.6%
= 2.3%
Average Water Absorption 2.45%
Effect of Partial Replacement of Coarse Aggregate by Crushed Broken Glass on Properties of
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Table 6 Specific Gravity of Dangote Cement
DESCRIPTION SAMPLE A SAMPLE B
Mass of empty bottle(W1) (g) 28.0 27.8
Mass of bottle +cement (W2) (g) 50.2 49.6
Mass of bottle+cement+ kerosene (W3) 85.1 85.4
Mass of bottle +kerosene (W4) (g) 68.5 68.1
Mass of bottle + water (W5) (g) 77.9 78.4
SPof kerosene=
= 0.82 0.80
SP of Cement
= 3.08 3.11
Average specific gravity 3.1
From table 3, 4, 5 and 6 the specific or unit weight of sand having an average of 2.26and
coarse aggregate 2.45 whereas that of glass is 1.8584 this which is approximately 1.3 times or
about 25 to 30 % lighter than the coarse aggregate used making it a great light aggregate and
it will reduce the overall weight of the concrete.
3.3. Slump Analysis of the Fresh Concrete Mix
The slump ranged from 10 to 45mm which indicates and increase in the workability of the
concrete at the increase in the percentage of the glass. It is obvious that the bond between the
cement and the aggregate reduced at the increase in the glass percentage leading to increase in
the workability.
The following results were obtained from the cone slump test having height 300mm
performed within 2minutes of batching and mixing.
Figure 5 Results for Slump Test
3.4. Density Analysis of Hardened Concrete
From the concrete weight, different densities are thus computed below after 24 hours of
moulding with cubes having surface volume of 150mmx150mmx150mm in accordance to EN
12390-7, BS1881:114.
Densities of the normal concrete is higher than that of the glass concrete. The concrete
density decrease at the increase in the percentage of the glass. This reduction in density is as a
result of low specific gravity of glass compared to normal coarse aggregate. The light density
of glass concrete makes it suitable for Super structure especially in high rise structures.
0
10
20
30
40
50
10
20
40 40 45
Slu
mp
(m
m)
Plot of the % of Glass repalcement against the Slump
0% Glass 15% Glass 25% Glass 35% Glass 45% Glass
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After batching casting and de-moulding after 24 hours the following results were obtained
for the various concrete from control to glass at various water cement ratio. As shown below.
Figure 6 Average Density of Concrete after curing for 7, 14 and 28 days
From the figure above the lowest glass concrete density is 2394.07kg/m3 which is not too
far from the normal concrete density of 2400 kg/m3
minimum.
3.5. Water Absorption of Concrete after the Curing Period
This is presented as the percentage of water absorbed by standard and sawdust Concrete for
various curing period. The water absorption capacity of the concrete is determined by the
changes in the weight of the cubes after the curing days and this done with the formula below
Wabs =
the percentage absorption for the different water
cement ratio.
The result obtained from the water absorption test is summarized in the table below.
It was observed that the percentage of water absorbed by the concrete decrease at the
increase in the percentage of glass. This could be attributed to the impermeable nature of the
glass and this reduces the effects the curing would have hard on the strength of the concrete.
Figure 7 Water Absorption capacity of the Concrete for 7, 14 and 28 days
From figure 7, the best water absorption capacity of the concrete was achieved at the 20%
replacement with glass while the normal concrete gave the best water absorption capacity.
2250
2300
2350
2400
2450
2500
2550
2600
2650
0 15 25 35 45
De
nsi
ty (
(Kg/
m3
)
% of Glass
Densities of the Glass Concrete (Kg/m3)
7
14
28
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 15 25 35 45
% o
f w
ate
r ab
sorb
ed
% of Glass
Water Absorption of the Concrete
7
14
28
Effect of Partial Replacement of Coarse Aggregate by Crushed Broken Glass on Properties of
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3.6. Compressive Strength of Concrete after 7, 14, and 28 Days Curing
After the curing and the concrete crushed with the compression machine, the load tabulated in
Table 16, thus the compressive strength calculated using the expression
Fcu =
for the mean crushing load.
The compressive strength of the concrete reduced gradual at the increase in the percentage
of the coarse aggregates replaced with coarse glass aggregate. It was observed that the 7days
strength of the glass concrete was higher than that of the normal aggregate, but the strength as
the curing days increased could not improve more that of normal concrete.
The best strength of the concrete was achieved at the 25% replacement with glass, since
the in 28days compressive strength
Figure 8 Compressive strength of the Concrete for 7, 14 and 28 days
3.7. The Engineering Properties of the Various Concrete Sample at 28 days of
Curing.
From the table it observed that at 25% replacement of coarse aggregate with glass gives an
optimal value of various properties of concrete after 28 days curing.
Table 7 Summary of the Engineering properties of the Concrete.
% of Glass Compressive
Strength (N/mm2)
Density
(Kg/m3)
Slump (mm) Water Absorption
0 26
2612.71 10 1.5129
15 25.04
2530.37 20 1.25
25 24.37 2444.44 40 1.23
35 22.22 2446.91 40 1.0797
45 21.55 2530.37 45 1.0262
15.85
24.96 26
16.96
24.15 25.04
16.59
23.74 24.37
16.15
20.81 22.22
15.78
19.19 21.55
0
5
10
15
20
25
30
com
pre
ssiv
e s
tre
ngt
h o
f co
ncr
ete
(N/m
m2
)
COMPRESSIVE STRENGTH OF THE GLASS CONCRETE (N/mm2)
0% GLASS
15% GLASS
25% GLASS
35% GLASS
45% GLASS
7DAYS 14 DAYS 28DAYS
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4. CONCLUSION AND RECOMMENDATION
4.1. Conclusion
The major objectives of this work are examining the possibility of re-using glass waste as a
partial replacement for coarse aggregates in concrete production. The properties of the glass
such as it particle distribution and specific gravity were determined. It was observed that the
specific gravity of the glass used for the study fall below the specific gravity in the normal
granite coarse aggregate by about 1.3 times and this caused a reduction in the overall weight
and densities of the concrete.
It was observed that the percentage of water absorbed by the concrete decrease at the
increase in the percentage of the glass. This could be attributed to the impermeable nature of
the glass and this reduced the effects the curing would have hardened on the strength of the
concrete.
The workability of the concrete increase with increase in the glass percentage owing to the
fact that the bond between the aggregates and the reduced to the reduction in the plasticity of
the concrete at the increase in the glass content.
The compressive strength of the concrete reduced gradually at the increase in the
percentage of the coarse aggregates replaced with coarse glass aggregate. It was observed that
the 7days strength of the glass concrete was higher than that of the normal aggregate, but the
strength as the curing days increased could not improve more that of normal concrete.
The control mix generally gave more strength than that of the glass concrete, but the best
strength of the concrete was achieved at the 25% replacement with glass, since the in 28days
compressive strength. The 25% strength is 25.04KN/m3 which is just about 3.8% lower than
that of the normal concrete mix therefore it is concluded that the aggregates can be replaced
effectively by waste glass up to 25%.
Utilization of waste glass in concrete production will invariably help to reduce the
negative impact of these waste on the environment and will reduce in no small measure the
over cost of concrete production.
4.2. Recommendations
Based on the results, discussions and conclusions, the following recommendations are made:
A compromise between the strength of concrete, cost savings of fine aggregate replacement
and reduction of pollution to the environment would allow a replacement of up to 25% of the
coarse aggregate by waste glass. Since the concrete produced is light weight it will can
efficiently use in high rise structures will load reduction is needed.
The concrete mix with coarse aggregate replaced by waste glass should be incorporated with a
good admixture such as plasticizer to reduce the rate of segregation and bleeding. This will
definitely improve the strength of the concrete by up to 50%.
I recommend a further research on the effect of the chemical composition of the glass
aggregate on the concrete strength and as well as examination of the strength properties of the
glass such as aggregate split tensile strength and abrasion test.
Due to its low water absorption capacity in its core matrix it is should not be used in areas
prone to concrete shrinkage resulting from excess heat like the Northern part of Nigeria.
Effect of Partial Replacement of Coarse Aggregate by Crushed Broken Glass on Properties of
Concrete
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REFERENCES
[1] ASTM C33 / C33M, “Standard Specification for Concrete Aggregates”, National
Bookstore, Manila, (2004).
[2] British Standards Institution (1975) BS 812-1:1975 Testing aggregates – Part 1: Methods
for determination of particle size and shape, London; BSI.
[3] B.S. 1377 (1990): Methods of Testing of Soils for Civil Engineering Purposes, British
Standards Institute, London, United Kingdom.
[4] EN 12390-2BS 1881:111 Testing Hardened Concrete – Part 2: Making and Curing
Specimens for Strength Tests
[5] EN 12390-3UNI 6132 Testing Hardened Concrete – Part 3: Compressive Strength of Test
Specimens
[6] EN 12390-6BS 1881:117 Testing Hardened Concrete – Part 6: Tensile Splitting Strength
of Test Specimens NF P18-408
[7] EN 12390-7 BS 1881:114 Testing Hardened Concrete – Part 7: Density of Hardened
Concrete
[8] Esraa Emam A. and Sherif H.A., (2012) “Recycled glass as a partial replacement for fine
aggregate in self-compacting concrete” Construction and Building Materials 35 (2012)
785–791
[9] Khatib J.M., Negim E.M., Sohl H.S., and Chileshe N (2012). Glass powder utilisation in
concrete production. European Journal of Applied Sciences, 2012; 4 (4):173-176.
[10] Mtallib, M. O. A; Rahiu, A (2009): Effect of Egg Shell Ash on the Setting Time of
Cement. Nigerian Journal of Technology, Vol. 28, No. 2.
[11] Punch Neswpaper, (December, 2012), „‟ FHA seek 300b naira intervention fund for
housing sector‟‟ Lagos, Nigeria
[12] Rashed, A.M., (2014). Recycled Waste Glass as Fine Aggregate Replacement in
Cementitious Materials Based on Portland cement. Constr. Build. Mater. 72, 340–357.
[13] Robert Boakye, (2012). Impact of waste on Urban Water Surface resource: case study of
Aboabo Kumasi Ghana.
[14] Taha, B. and Nounu, G. (2008a) Properties of concrete contains mixed colour waste
recycled glass as sand and cement replacement, Construction and Building Materials,
22(5), pp. 713-720.
[15] Terro, M. J. (2006) Properties of concrete made with recycled crushed glass at elevate
temperatures, Building and Environment, 41(5), pp. 633-639.
[16] Topcu, I. B. and Canbaz, M. (2004) Properties of concrete containing waste glass, Cement
and Concrete Research, 34(2), pp. 267-274.
[17] Zammit, L., Montesin, F. E. and Torpiano, A. (2004) the use of crushed glass waste as
fines in concrete construction, Proceedings of the international conference on sustainable
waste management and recycling: glass waste, University of Malta, pp.125-131.
[18] Zhu, H. Y. and Byars, E. (2005) Potential for use of waste glass in concrete, Department
of civil engineering, University of Sheffield, concrete London, 39(2) pp.41-45.
