Flowable concrete for economy, quality, speed and sustainability

1. International Journal of Zero Waste Generation
Vol.1, No.1, 2013; ISSN 2289 4497
Published by ZW Publisher
1
Alternative Aggregates for Sustainable
Construction
Lee Yee Loon*, Ahmad Tarmizi Abd Karim*, Ismail Abdul Rahman*, Koh Heng Boon*, Suraya Hani*, Sasitharan Nagapan*
Fetra Venny Reza *
* Faculty of Civil and Environmental Engineering, University Tun Hussein Onn Malaysia, Malaysia
Corresponding Author: ahloon@uthm.edu.my
Abstract - This paper summarizes the achievements of a long
term research programme focused on the exploitation of
solid wastes in construction. The objective of the research
programme is to develop an environmental-friendly and
economical process for the exploitation of solid wastes in
construction. The solid wastes experimented include fly ash,
timber industrial ash, rice husk ash and palm oil fuel ash.
Other solid wastes include biomass particularly rice husk
and palm fiber and paper sludge. Packaging wastes such as
recycled expanded polystyrene are also explored. An
engineered foamed grout and shear wall system with the
combination of recycled expanded polystyrene and
lightweight concrete has been developed. It provides an
environment-friendly and economical solution to
construction on soft soil, towards providing affordable
quality assured fast track method and to enhance the
competitive edge of the construction industry. Obstacles
toward achieving commercialization are briefly discussed.
Keywords-aggregates; solid wastes; environmental; fly ash;
commercialization
I. INTRODUCTION
A. Exploiting Wastes in Concrete
Among researchers who have made significant
contribution to knowledge include Samarin [1] who
reviewed the impact of Kyoto Protocol. New levels of
abatement of greenhouse gas emissions by the year 2012
was stipulated, on the utilization of cement extenders in
concrete, and on the use of wastes as new materials. Naik
et al. [2] studied the use of industrial by-products in
cement-based materials. He quoted that nearly 4.2 billion
tonnes of non-hazardous by-products are generated from
agricultural, domestic, industrial and mineral sources. He
emphasizes the need for recycling to conserve natural
resources and to provide technical and economic benefits.
Shoya et al. [3] studied the properties of self-compacting
concrete with slag fine aggregates. He conducted the
slump-flow test, the V-type funnel test and filling vessel
tests for the measurement of self compatibility of fresh
concrete. Mellmann et al. [4] investigated the exploitation
of processed concrete rubble for reuse as aggregates. He
described the feasibility of producing high-grade concrete
from the rubble. Rad and Bonner [5] studied the properties
and performance of recycled cementitious mortars. They
attempted to link the petrological observations to the
microstructural characteristics of cement gel interaction
and activation. Bijen [6] proposed the use of secondary
materials as a contribution to sustainability. He assessed
the environmental impact in accordance with the draft ISO
standards 14040 series. Ledham et al. [7] experimented on
simple treatments to reduce the sensitivity to water of
clayey concretes lightened by wood aggregates. They
envisaged the potential use of local materials with
hydraulic lime coating for the production of insulation
materials. Mimoune et al. [8] used fly ash in the compound
wood-cement. They concluded that the addition of fly ash
did not resolve elasticity problems during decompression.
II. ASH UTILIZATION RESEARCH
A. Fly ash
Coal ash production and its use in concrete were
studied by Manz and Stewart [9, 10]. They reviewed the
worldwide production and utilization of coal ash from
1959 to 1989 for the UN Group of Experts on the
Utilization of Ash. Quantities of fly ash recycled in each
sector of the construction industry are given. Wang [11]
stated that the fly ash production in China was
approximately 100 million tons per year in 1997. Puch
and Vom Berg [12] reported that the coal combustion by-
products in Germany are being recycled at a rate over
98%. Dube [13], Uchida [14], Bland et al. [15], and Zysk
& Volke [16], Colmar [17] and others [18, 19] review the
use and utilization of fly ash in cement manufacturing and
construction. Jagiella [20] studied the utilization of coal
combustion by-products such as fly ash, bottom ash, boiler
slag, flue gas desulfurization (FGD) material and fluidized
bed combustion (FBC) by-products. Barringer [21]
proposed a proportioning method based on the price,
availability, and strength-gaining ability of the fly ash.
B. Materials Characterization
Galpern et al. [22] discussed the properties of ashes
from fluidized bed with and without addition of
lime/carbonate. They have reported that addition of up to
20-30% of low carbonate ash to cement does not affect the
durability. Ninomiya et al. [23] studied the effects of
adding carbonate to ashes during melting. High
temperature phase transformations were studied by XRD
analysis and the glass phase was studied by FT-IR
analysis. It was shown that addition of carbonates results
in a glass phase with a higher pozzolanic reactivity than
the parent coal glass. Hower et al. [24] studied the quality
of fly ash and its carbon content obtained from boilers
converted to low-NOx combustion. Other parameters
include fineness and the relative amount of glass versus

2. www.zwgm.org International Journal of Zero Waste Generation Vol. 1 No. 1, 2013
2
crystalline inorganic phases. It is shown that the post-
conversion fly ash was higher in carbon than the pre-
conversion ash from the same unit.
C. Effect of Grinding
Bouzoubaa et al. [25] studied the effect of grinding on
the physical properties of ASTM Class F fly ashes. The
specific gravity and the fineness are significantly increased
with grinding up to two hours. Ruan et al. [26] used fluid
energy mills to grind fly ash. Paya et al. [27] demonstrated
that the grinding fly ash increases its pozzolanic activity
and enhanced the mechanical properties of mortar. A
mathematical model was developed to predict the
mechanical properties of mortars containing ground fly
ash. Kruger [28] described means of separation of fly ash
particles to obtain fractions with different characteristics.
These methods include air classification, electrostatic
recovery, and density separation. Yoshida et al. [29] used
an air-cyclone to classify particles of fly ash to a mean
diameter 2 and 6 mm. Murai et al. [30] reported that fly
ash particles of less than 10 mm affect the rheology,
strength, water tightness, shrinkage, and durability of self-
compacting concrete in a comparable or better way than
ordinary fly ash, GGBS, and limestone filler. Okoh et al.
[31] investigated the kinetics of oxidation of residual
carbon as a step toward producing low-carbon fly ash from
high-carbon, low quality fly ash.
D. Biomass Fly Ash
Meyrahn et al. [32] reported that biomass fly ashes
have very low content of heavy metals and possess
pozzolanic as well as hydraulic properties. Ludwig and
Urbonas [33] and Bartscherer-Sauer et al. [34] studied
granulometric and chemical-mineralogical properties of fly
ash from biomass-fired power stations. Kahl et al. [35]
compared the composition of biomass fly ashes produced
in different power stations. Dietz et al. [36] studied the
composition, strength and durability properties of German
biomass fly ash. Volume stability, as well as carbonation
depth, sulfate resistance, and freeze-thaw resistance were
investigated. It was demonstrated that additions up to 10-
15% do not lead to negative effects on fly ash cement
properties.
E. Hydration and Microstructure
Chang et al. [37] measured various aspects of
workability, bleeding, setting, compressive and tensile
strengths, pore distribution, and crystal structure of cement
pastes containing fly ash from fluidized bed incineration
systems. Anthony et al. [38] studied the activation of
unreacted calcium by means of injecting limestone into the
furnace. They report hydrated tetracalcium aluminate as
the major hydration product of the activation process.
Poon et al. [39] studied the influence of two different
curing conditions (in water at 27°C, and in air at 15°C and
60% relative humidity) on the compressive strength,
chloride, and water penetration properties of fly-ash
cement pastes and mortars. Mercury intrusion porosimetry
showed that curing conditions has a significant influence
on the strength, porosity, and durability of cement pastes
and mortars.
F. Palm Oil Fuel Ash
The pozzolanic properties of palm oil fuel ash, a waste
material obtained on burning of palm oil husk and shell,
was studied by Hussin et al. [40]. Compressive strength
test with Portland cement substitution levels between 10-
60% indicate the possibility of replacing 40% ash without
affecting concrete strength. A maximum strength gain at
the 30% level was achieved. Awal et al. [41] utilized palm
oil fuel ash to reduce the expansion of mortar bars
containing tuff as a reactive aggregate. According to the
results, the palm oil fuel ash has a good potential in
suppressing alkali-silica reaction expansions.
G. Applications
Cabrera and Al-Hasan [42] used a pozzolanic
compound containing 70% Portland cement and 30% fly
ash for maintenance, repair and strengthening of concrete
structures. The compressive strength, bond strength,
porosity, and permeability were measured. Lee et al.
[43-53] explored the use of timber industrial ash in a
variety of blended cement products such as bricks, paver
blocks, lightweight palm clinker concrete, foamed concrete
engineered shear wall and foamed grout for soft soil
stabilization. Water permeability test system has been
developed based on ISO/DIS 7031.
III. OTHER SOLID WASTES
A. Paper Sludge
Paper sludge is one of the solid wastes produced by
paper industry. Paper sludge contains fragments of paper
fiber. These fibers are not suitable for use in recycled
paper. Disposal options include landfill and energy
production. Usually in the paper production, only 65% of
the paper pulp will be turn into paper, the other 35% will
be the waste material in the form of paper sludge. Paper
sludge contains a high percentage of very fine kaolin clay
and fillers, which is used to create a smooth finish on fine
paper. Besides kaolin, there are also other contaminants in
the paper sludge, such as de-inking compounds,
surfactants, residuals from inks and dyes, compounds from
laser printing, photocopying and also coagulant that has
been used to coagulate the paper sludge during the
disperser process. Heavy metals is one of the contaminants
exist in paper sludge. Some of these metals are toxic to
plants, animals and also human being. When the paper
sludge is dumped in the dumpsite, there are possibilities
for leachate from the sludge to get into groundwater, stock
ponds, or drinking wells. Besides, when the paper sludge is
dumped in the dumpsite, it will undergo anaerobic
decomposition and this will cause odour problem. A paper
mill in Malaysia. produces 30 metric tonnes of paper
sludge per day and the cost for transporting the paper
sludge to the dumpsite is approximately RM 10,000 per
month.
B. Rice Husk
Rice is a basic food in Asian countries such as
Malaysia, Thailand, Indonesia, India and Japan. It is
abundantly available in most part of the world. Substantial
amounts are also cultivated in various countries in
America and Europe. The present world rice production of

3. www.zwgm.org International Journal of Zero Waste Generation Vol. 1 No. 1, 2013
3
about 400 million tons per year will probably increase in
the future, owing to the great increase in population,
particularly in Asian countries. When rice grains are
husked, the husks make up about 14 to 35%, depending on
the variety of rice. Since the husks have a low bulk weight
of about 100 kg/m3
, they take up 560 to 1400 million m3
.
Although rice husk has its traditional uses, it is mostly
under-utilized and causing disposal problem in most
countries. It is estimated that 54 million tons of rice husk is
produced in China every year. According to a recent study,
Malaysia generates about 3.41 million m3
of rice husk
annually. Innovative exploitation is crucial to avoid the
waste of energy and environmental pollution.
IV. LIGHTWEIGHT CONCRETE
Lightweight concrete containing palm clinker fine
aggregate and micronized silica was known as TIA
composite. It is a mixture of cement, fine sand, water and
special foam, which once harden results in a strong,
lightweight concrete containing millions of evenly
distributed, consistently sized air bubbles. It differs from
conventional concrete in that the use of coarse aggregates
is eliminated. The density of TIA composite is determined
by the amount of foam added to the cement, sand and
water mixture. TIA composite’s density ranges from 250
to 1800 kg/m3
, as compare to 2400 kg/m3
for conventional
concrete. Therefore, the weight of a structure built of TIA
composite will be reduced significantly. TIA composite is
water-resistant and possesses enhanced sound and thermal
insulation properties. Foam generation requires a foaming
agent and a foam generator. A foam generator is developed
from a compressed air vessel incorporating a foaming
compartment which allows the foaming agent to be
agitated by a stream of compressed air.
Fine sand, cement and water are mixed in accordance
with the design-mix charts taking into consideration
suitable property-enhancing materials like fiber and other
pozzolan and/or cementitious products. Cement and Sand
are mixed first. Water is then added to the mix to form
slurry. Foam is then added to achieve controlled density. If
1 liter of this mix weighs 1 kg then the density is 1000
kg/m3 (Normal concrete has a density of 2400 kg/m3
).
Curing is the same as normal concrete. TIA composite can
be remolded after 16 hours. TIA composite is
recommended to be moist-cured at least for the first 2
days.
The water/cement ratio must be strictly followed since
too little water might cause the cement to draw its
requirement from the foam, causing the latter to collapse
partly or in total. The foam allows any density of concrete
from as low as 250 kg/m3
to 1800 kg/m3
to be produced
with an optimum ratio of strength-to-density. The possible
wide range of densities achievable thus offers multiple and
diversified applications, such as site mixing, off-site
mixing, prefabrication, pre-cast or cast in place.
An average compressive strength of 2.86 MPa has been
achieved for TIA composite cubes with an average density
650 kg/m3
subjected to 28 days of standard moist-curing.
Tests on other densities revealed that 28-day strength
exceeding 15 MPa is achievable depending on the density
of the mix. Studies also show that compressive strength of
above 20 MPa is possible with the addition of short fiber
and mesh reinforcements. TIA composite is expected to
have a life span of over 100 years. Previous investigation
has shown that sectioned blocks of similar foamed
concrete cast 10 years ago indicated only 75 percent of the
cement hydrated. It is expected that the strength would
continue to increase with continuing hydration. The
availability of TIA composite in many cases provides a
better alternative to other man-made products such as clay
bricks and other insulation materials.
Curing is essential as in conventional concrete, as
cement-based elements need moisture for hydration at an
early age. This is particularly true in the presence of direct
sunlight that is known to cause rapid dehydration of
concrete surfaces. Curing compound can be applied as an
alternative barrier. TIA composite is also suitable for
special roof deck with enhanced acoustic thermal
insulation and water proofing properties. TIA composite of
density between 250 – 550 Kg/m3
is primarily used for
thermal insulation or fire protection. It uses only cement
(or with a small proportion of sand), water and foam for
insulation board as an alternative to polystyrene,
polyurethane or mineral wool, with no hazardous elements
to health and environment.
V. ENGINEERED COMPOSITE WALL
SYSTEM
A composite building system is developed from a
combination of lightweight concrete containing micronized
silica and recycled expanded polystyrene (EPS) insulation
panels for wall and floor. The system offers advantages of
economy and speed, comfort and energy efficiency. The
salient features include the use of EPS panel with
interlocking profile, webs and pipes, designed to achieve
enhanced acoustic and thermal insulation properties
compared to the traditional building system.
The engineered composite wall system is a novel
method of construction. It combines the art of
manufacturing a modular system formed from a self-
compacting lightweight reinforced concrete and a method
of vertically moulding it. The system is aimed at providing
a new and improved moulded building panel, construction
and connection methods for optimal control of the
moulding and interconnecting process for such precast
building panels, towards enhancing construction safety,
quality and productivity.
A long felt need in the construction industry is to find a
durable, yet relatively inexpensive construction method
and material that would allow the construction of attractive
and durable homes in a quick and economic manner.
Although the thrust of this need has initially been to
provide housing for low-income families or for the first
time home buyers, any such construction method and
material could also be easily adapted for more expensive
homes and multi-family housing units.
VI. SOFT SOIL FOUNDATION SYSTEM
A method of improving soft ground containing organic
material may consist of cement, water, fly ash, micronized
silica, bentonite and a lightweight particles such as

4. www.zwgm.org International Journal of Zero Waste Generation Vol. 1 No. 1, 2013
4
volcanic ash. The composition is injected at prescribed
locations to effect replacement of portions of the soft
ground. The composition which solidifies in situ can be
used in combination with lightweight friction piles to offer
the optimum solution for soft soil stabilization. TIA
composite in the form of slabs of 600mm thick can be cast
to achieve required level. Experimental construction of
load bearing block with hollow section in filled with
lightweight concrete has been done in Sibu Sarawak.
VII. RESEARCH SHOWCASE – ALTERNATIVE
AGGREGATES
A. Biomass aggregate
Twenty years of intensified research into the synthesis
of biomass aggregate www.biomass.org.my is beginning
to create the impact. It is derived primarily from the
innovative exploitation of solid wastes from controlled
incineration of biomass. A novel process for the synthesis
of micronized silica from controlled incineration of
biomass in a rice husk-fired power plant has won the EC
cogen award in 2003. It has been initiated in collaboration
with a rice mill in Bukit Raya, Kedah, Malaysia.
Cementitious composites and concrete products containing
micronized silica have attracted much research interest and
the award of research grants. A summary of research
showcase is available online via a research achievement
portal www.1.net.my. The effective use of information and
communication technology enables interested researchers
to share useful research knowledge and skill towards
exploration and discovery beyond the frontiers of
knowledge. A rotary furnace is developed to provide
controlled incineration of rice husk to study the effect of
incineration temperature and retention time on the quality
of rice husk ash. The system will be integrated with
opposed jet mill to produce micronized silica.
B. Recycled aggregate
Recycled aggregates are defined as aggregates
resulting from the reprocessing of mineral construction
materials (i.e. composed predominantly of crushed
concrete and brick masonry). Waste aggregates produced
from construction industry have increased rapidly around
the world [56]. Construction waste such as material wasted
on construction sites generated from ordering errors,
damages caused by third parties, vandalism at site, effect
of weather, rework, inventory of materials not well
documented, damage caused by workers, supplier errors,
wrong material delivery procedures, poor attitudes of
workers etc, as well as demolition waste, may provide
source material. Recycled aggregates can contain, in some
circumstances, significant quantities of natural aggregates;
but excessive quantities of other materials such as wood,
metal and plastic need to be removed before the aggregate
is fit for use.
With world population hitting the 7 billion mark at the
end of 2011, there is a need to assess the demand for
sustainable construction materials. Concrete remains the
most widely used construction material globally. The
annual production of concrete is estimated to be 7 billion
cubic meter. The demand for aggregate is estimated to be
15 billion tons per year. Effort to use alternative aggregates
have to consider technical, environmental and economical
advantages. Singapore BCA has approved the use of
copper slag as an alternative aggregate in concrete.
Expanded coal aggregate [57] has been studied in UTHM
for the development of a mix design nomograph.
VIII. CONCLUSION AND CHALLENGES AHEAD
Much attention is focused recently on the
commercialization of research products. Despite the fact
that researchers are given tax exemption on income such as
royalty received from the commercialization of their
research products, the success rate of commercialization
has been modest in Malaysia. Most researchers need
support services from patent agents to draft patent
specification and the involvement of successful
businessmen in the preparation of winning business plan.
There is also a need for researchers to be aware of the
mindset of businessmen in order to enhance their
negotiation skill.
A method of soft soil stabilization with foamed
concrete and biomass aggregate has been experimented in
Sibu Sarawak. It is envisaged that such system is
competitive and have potential to expedite the
development of the areas with deep deposit of soft soil.
Innovative foundation system with the utilisation of used
tyres is being experimented in some projects. The
engineered wall system which is expected to revolutionize
the construction process has been demonstrated in UTHM
to pave way for industrialization.
ACKNOWLEDGMENT (HEADING 5)
The authors wish to acknowledge Cradle Fund
(www.cradle.com.my), Ban Heng Bee Rice Mill (1952)
Sdn. Bhd. (www.malaysiarice.com) for the proof-of-
concept activities and Your Website Solution Sdn. Bhd.
(www.1.com.my) for the maintenance of the research
portal www.1.net.my.
REFERENCES
[1] Samarin, A., “Wastes in concrete: Converting liabilities into
assets,” Proceedings of the International Seminar on Exploiting
Wastes in Concrete, Thomas Telford , 7 September 1999 p 1-21.
[2] Naik, T.R.; Kraus, R.N., “Use of industrial by-products in cement-
based materials," Proceedings of the International Seminar on
Exploiting Wastes in Concrete, Thomas Telford , 7 September
1999 p 23-35.
[3] Shoya, M.; Sugita, S.; Tsukinaga, Y., Aba, M., Tokuhasi, K.,
“Properties of self-compacting concrete with slag fine aggregates,”
Proceedings of the International Seminar on Exploiting Wastes in
Concrete, Thomas Telford , 7 September 1999 p 121-130.
[4] Mellmann, G.; Meinhold, U., Maultzsch, M., “Processed concrete
rubble for the reuse as aggregates”, Proceedings of the
International Seminar on Exploiting Wastes in Concrete, Thomas
Telford , 7 September 1999 p 172-178.
[5] Rad, T.; Bonner, D.G., “Properties and performance of recycled
cementitious mortars”, Proceedings of the International Seminar on
Exploiting Wastes in Concrete, Thomas Telford , 7 September
1999 p 189-197.
[6] Bijen, J.M.,“Secondary materials: A contribution to sustainability?
,” Proceedings of the International Seminar on Exploiting Wastes
in Concrete, Thomas Telford , 7 September 1999 p 209-216.
[7] Ledham, A.; Bouguerra, A., Dheily, R.M., Queneudec, M.,
“Simple treatmens to reduce the sensitivity to water of clayey

5. www.zwgm.org International Journal of Zero Waste Generation Vol. 1 No. 1, 2013
5
concretes lightened by wood aggregates,” Proceedings of the
International Seminar on Exploiting Wastes in Concrete, Thomas
Telford , 7 September 1999 p 217-225.
[8] Momoune, F.Z.; Momoune, M.; Laquerbe, M., “The use of fly ash
in the compound wood-cement,” Proceedings of the International
Seminar on Exploiting Wastes in Concrete, Thomas Telford , 7
September 1999 p 1-21.
[9] Manz, O.E.; Stewart, B.R., “Highlights of worldwide production
and utilization of coal ash - a survey for the period 1959-1989,
"Proceedings of the American Power Conference Proceedings of
the 1997 59th Annual American Power Conference. Part 2 (of 2) v
59-2 1997 Chicago, IL, USA.
[10] Manz O.E., “Worldwide production of coal and utilization in
concrete and other products,” Fuel 1997, 76(8), pp. 691-696.
[11] Wang, L.L., “Study of the comprehensive utilization of flyash and
its sustainable development uses in China,” Proceedings of the
1997 Annual Conference - Canadian Society for Civil Engineering,
Sustainable Development, Environment, Geotechnical
Engineering, Transportation. Part 5 (of 7) May 27-30,1997
Sherbrooke, Canada.
[12] Puch, K.H.; vom Berg, W., “Nebenprodukte aus kohlebefeuerten
Kraftwerken By-products from coal-fired power plants - analysis
of VGB surveys for the years 1985 to 1995 VGB
Kraftwerkstechnik v 77 n 7 Jul 1997 p 604-610.
[13] Dube, S.K., “Need of advanced technologies for coal ash
utilization programs,” Proc. American Power Conference 1997,
59(2), pp. 818-823 (Chem. Abs. 127, 152092).
[14] Uchida S., “Characteristics and use of coal ash.,” Muki Materiaru
1997, 4(270), pp. 544-547 (Chem. Abs. 127, 322060).
[15] Bland A.E.; Brown T.H.; Wheeldon J.M., “Pressurized fluidized
bed combustion ash .1. Construction-related use options," FUEL
1997, Vol 76, Iss 8, pp 733-740.
[16] Zysk K.H.; Volke, K., “The use of residues from power plants in
building materials and mining," DGMK Tagungsber. 1997, 9704,
(Proc. ICCS '97 Vol.3), pp.1943-1946 (Chem. Abs.127, 322063)".
[17] Colmar, J.A., “Economic realities of coal combustion by-product
utilization ,,"Proceedings of the American Power Conference
Proceedings of the 1997 59th Annual American Power
Conference. Part 2 (of 2) v 59-2 pp. 812-817 1997 Chicago.
[18] Williams, D., “Ashes to cash: utilities are building steam in
recycling,” Pollution-Engineering, v. 29 Apr. '97 p. 46-7.
[19] Xu, A.“Fly ash in concrete,” Waste Materials Used in Concrete
Manufacturing, 1997, pp.142-183 (Chem. Abs. 127, 69693).
[20] Jagiella, D., “Reuse of coal combustion by-products: A new profit
center,” Proceedings of the 59th Annual American Power
Conference. Part 2 (of 2) v 59, pp. 812-817 Chicago, IL, USA.
[21] Barringer,W.L.,“Before using fly ash” Concrete International. v. 19
Apr. '97 p. 39-40.
[22] Galpern E. I.; Pashchenko, L. V.; Borisov A.P., “The utilization of
coal ash in building materials production," DGMK Tagungsber.
1997, 9704, (Proc. ICCS '97 Vol.3) pp. 1935-1938 (Chem. Abs.
127, 322087)".
[23] Ninomiya, Y.; Sato, A., “Ash melting behavior under coal
gasification conditions,” Energy Conversion and Management
Proceedings of the 1995 International Symposium on Advanced
Energy Conversion Systems and Related Technologies, Dec 4-6
1995 v 38 n 10-13 Jul-Sep 1997 Nagoya, Japan, pp.1405-1412.
[24] 2Hower,J.C.; Rathbone, R.F.; Robl,T.L., “Case study of the
conversion of tangential-and wall-fired units to low-NOx
combustion: impact on fly ash quality,” Waste-Management,
v.17,no4,97,p.219-29.
[25] Bouzoubaa, N.; Zhang, M.H.; Bilodeau, A.; Malhotra, V.M.,
“Effect of grinding on the physical properties of fly ashes and a
Portland cement clinker,” Cement and Concrete Research v.27 n12,
Dec 1997, pp1861- 1874.
[26] Ruan, Y.; Pan, G.; Gao, Q., “Study of super high strength concrete
by adding ground ultrafine fly ash,” Dalian Ligong Daxue
Xuebao/Journal of Dalian University of Technology, v. 37, No.1,
Aug 1997.
[27] Paya, J.; Monzo, J.; Borrachero, M.V.; Peris, E.; Gonzalez Lopez,
E., “Mechanical treatments of fly ashes .3. Studies on strength
development of ground fly ashes (GFA) - Cement mortars,”
Cement and Concrete Research, 1997, Vol 27, Iss 9, pp 1365-1377.
[28] Kruger RA, “Fly ash beneficiation in South Africa: Creating new
opportunities in the market-place,” FUEL 1997, Vol 76, Iss 8, pp
777-779.
[29] Yoshida, H.; Yamamoto T.; Okanishi K.; Morisaki H.; Nakamura
T.; Ilinoya K., “High-accuracy classification of fly-ash particles by
a bench-scale air-cyclone,” Kagaku Kogaku Ronbunshu , 1997,
23(3), pp.363-370.
[30] Murai, H.; Kobayashi, T.; Nagaoka, S., “The application of
classified fly ash to self compacting concrete,” Semento Konkurito
Ronbunshu 1997, 51, pp. 316-321. (Chem. Abstr. 128, 208174)".
[31] Okoh, J.M.; Dodoo, J.N.D.; Diaz, A.; Ferguson, W.; Udinskey, J.R.
Jr.; Christiana, G.A., “Kinetics of beneficiated fly ash by carbon
burnout,” Proceedings of the 22nd International Technical
Conference on Coal Utilization & Fuel Systems, Mar 16-19,1997
Clearwater, FL, USA.
[32] Meyrahn, H.; Paeffgen, H.P.; Reich-Walber, M.; Greif, H.G.,
“Verwertung von rheinischen Braunkohlenflugaschen Utilization
of Rhine brown coal fly ash, VGB Kraftwerkstechnik v 77 n 1 Jan
1997 p 61-65 ISSN: 0372-5715.
[33] Ludwig, U.; Urbonas, L.“Untersuchungen zur Verwertung
mitteldeutscher Flugaschen aus braunkohlebefeuerten Kraftwerken
zur Herstellung von Baustoffen Investigations into the utilization
of fly ash from lignite-fired power stations in central Germany for
the production of construction materials, VGB Kraftwerkstechnik
v.77 n.2, Feb 1997, pp150-155.
[34] Bartscherer S. A.; Miskiewicz, K.; Kirchen, G.; “Eignung von
rheinischer Braunkohlenfilterasche fuer Baustoffe Suitability of
Rhine lignite filter ash for construction materials,” VGB
Kraftwerkstechnik, v.77 n1, Jan 1997, p 66-71, ISSN: 0372-5715.
[35] Kahl, D.; Piper, Kristina; Zabel, P., “Konzepte zur Verwertung von
Lausitzer Braunkohlenflugaschen Concepts for the utilization of
lignite fly ash from Lusatia,” VGB Kraftwerkstechnik v 77 n 2 Feb
1997 p 143-149.
[36] Dietz S.; Miskiewicz K.; Schmidt M., “Properties of cement
containing German lignite fly ashes”, 10th International Congress
on the Chemistry of Cement, 1997, Volume 3.
[37] Chang, Yu-Min; Lin, Lee-Kuo; Chang, Tien-Chin “Preliminary
assessment on reusage of flyash emitted from fluidized bed
incineration of sludge cake”, Resources, Conservation and
Recycling v 20 n 4 Aug 1997 pp.245-266.
[38] Anthony, E. J.; Iribarne, A. P.; Iribarne, J. V. “Study of hydration
during curing of residues from coal combustion with limestone
addition,” Journal-of-Energy-Resources-Technology. v. 119 June
'97 p. 89-95.
[39] Poon, C.S.; Wong, Y.L.; Lam, L., “Influence of different curing
conditions on the pore structure and related properties of fly-ash
cement pastes and mortars,” Construction and Building Materials
v. 11 n. 7-8 Oct-Dec 1997.
[40] Warid Hussin, M.; Abdul Awal, A.S.M.,“Palm oil fuel ash - a
potential pozzolanic material in concrete construction ,” Journal of
Ferrocement, v27 n 4 Oct 1997 Int. Ferrocement Information
Center Bangkok, Thailand p 321-327.
[41] Abdul Awal, A.S.M.; Warid Hussin, M.,“Effectiveness of palm oil
fuel ash in preventing expansion due to alkali-silica reaction,”
Cement & Concrete Composites v 19 n 4, Aug 1997 p 367-372.
[42] Cabrera, J.G.; Al-Hasan, A.S. “Performance properties of concrete
repair materials”, Construction and Building Materials v 11 n 5-6
Jul-Sep 1997 pp. 283-290.
[43] Lee, Y.L., Koh, H.B., Yeoh, David E.C., Shahabudin bin Mustapa,
Pang C. F., Yung-Tse Hung, “Exploiting solid wastes in
construction-Challenges ahead,” Proceedings Civil Engineering
Research Seminar, KUiTTHO (presented on 14 August 2004).
[44] Lee, Y.L., M.Warid Hussin & Khoo, K.O. (2000). "TIA Concrete
Mix Design Nomograph". Proceedings of the 4th Asia-Pacific
Structural Engineering & Construction Conference, pp. 279-287.
[45] Lee, Y.L., Hussin, M.W. & Khoo, K.O. (1999). "Timber Industrial
Ash Concrete". Proceedings of Sixth International Conference on
Concrete Engineering and Technology (CONCET '99). The
Institution of Engineers Malaysia, MARA Institute of Technology
& University of Malaya, (presented on 30 June 1999).

6. www.zwgm.org International Journal of Zero Waste Generation Vol. 1 No. 1, 2013
6
[46] Lee, Y.L., Khoo, K.O., Chong, S.S.F. & Hussin, M.W. (1999).
"Strength Development and Water Permeability of High Strength
TIA Concrete". Proceedings of International Congress on Creating
with Concrete University of Dundee, pp. 175-181.
[47] Lee, Y.L., A. Aziz Abu Bakar., M. Warid Hussin, Khoo, K.O.,
(2000). "TIA cement-lined pipes for waterworks", Proceedings of
3rd International Conference on Quality Reliability Maintenance,
University of Oxford-UNECIA-I Mech E, (presented on 31st
March, 2000).
[48] Lee, Y.L., Siow, K. & Hussin, M.W. (1997). "Agricultural Fly Ash
(AFA) - A Potential Alternative to Silica Fume for High
Performance Concrete", ITTHO-PERKOM-IEM Seminar on
Concrete Technology (R&D-97) themed Research & Development
for Competitive Advantage (presented on 2 October 1997).
[49] Lee, Y.L., Bani, S., McNulty, G.J. & Hussin, M.W. (1997).
"Acoustics Performance of AFA Concrete Paver Blocks", ITTHO-
PERKOM-IEM Seminar on Concrete Technology (R&D-97)
themed Research & Development for Competitive Advantage
(presented on 2 October, 1997).
[50] Lee, Y.L., M.Warid Hussin & Ken Siow, (1999). "Experimental
Production of Timber Industrial Ash (TIA) Cement Bricks:
Malaysian Experience". Proceedings of International Conference
on Infrastructure Regeneration and Rehabilitation. University of
Sheffield, pp. 287-296.
[51] Lee, Y.L., A. Aziz Abu Bakar., M. Warid Hussin, (1999). "Rice
Husk Ash and Timber Industrial Ash Composite - Potential
Materials for Low-Cost Housing", UTM Research Seminar, pp.
168-174 (presented on 4 February, 1999).
[52] Lee, Y.L. (1998). "Towards Achieving Quality Assured
Maintenance - Malaysian Experience" Proceedings of 2nd
International Conference on Planned Maintenance, Reliability and
Quality, Oxford, England, pp.143-148.
[53] Lee, Y.L. (1997). "Non-Destructive Testing of Concrete Structures
- Some Practical Aspects". Proceedings of Fifth International
Conference on Concrete Engineering and Technology (CONCET
'97), pp. 165-177 (presented on 6 May 1997).
[54] ISO/DIS 7031, (1983). Concrete hardened - Determination of the
depth of penetration of water under pressure.
[55] DIN 1048, (1972). Test Methods for Concrete – Impermeability to
Water, pp. 10.
[56] Nagapan, S., Rahman, I. A., Asmi, A., & Adnan, N. F. (2013).
Study of Site's Construction Waste in Batu Pahat, Johor. Elsevier
Procedia Engineering,53, pp. 99-103.
[57] Koh Heng Boon, Yew I Ying, Lee Yee Loon & Abu Bakar
Mohamad Diah. (2009) Design of ECS Concrete Mixes,
International Conference on Building Science and Engineering.G.
Eason, B. Noble, and I. N. Sneddon, “On certain integrals of
Lipschitz-Hankel type involving products of Bessel functions,”
Phil. Trans. Roy. Soc. London, vol. A247, pp. 529–551, April
1955.