Non‒Conventional Light‒Weight Clay Bricks from Homra and Kraft Pulp Wastes Original Research Article Journal of Chemistry and Materials Research Vol. 1 (4), 2014, 123–129 H. H. M. Darweesh,* and M. G. El-Meligy

1. Online available since 2014/ December /07 at www.oricpub.com
© (2014) Copyright ORIC Publications
Journal of Chemistry and Materials Research
Vol. 1 (4), 2014, 123–129
JCMR
Journal of Chemistry and
Materials Research
ORICPublications
www.oricpub.com
www.oricpub.com/jcmr
Cement notation: C: CaO, S: SiO2, A, Al2O3, F: Fe2O3, H: H2O.
Original Research
Non‒Conventional Light‒Weight Clay Bricks from Homra and Kraft
Pulp Wastes
H. H. M. Darweesh 1,
* and M. G. El-Meligy 2
1
Refractories, Ceramics and Building Materials Department, National Research Centre, Egypt
2
Cellulose and Paper Department, National Research Centre, Egypt
Received 24 September 2014; accepted 05 November 2014
Abstract
The main objective of this work is to study the reutilization of kraft pulp waste (KPW), which is the primary waste of the paper industry, in
clay brick. Due to the organic nature of the KPW, pore-forming ability in clay body was investigated. For this purpose, increasing amount of
residue (0, 2, 4, 6 and 8 wt. %) was mixed with clay (TC) and homra waste (H) to produce building bricks. The influence of KPW addition on
shaping, plasticity, density and mechanical properties of clay bricks was investigated. The addition of 2 to 6 % pulp waste was found to be
effective for the pore forming in clay body with acceptable mechanical properties. Moreover, the fibrous nature of pulp waste does not create
any extrusion problem, but the increase in its addition more than 6 wt. % increased the water content for the plasticity. As a conclusion, kraft
pulp wastes can be used safely as an organic pore-forming agent in the manufacturing of clay-bricks, The optimum batch composition was 6 %
KPW fired at 1000 ºC.
Keywords: Pulp waste; Clay brick; Plasticity; Density; Porosity; strength; SEM.
1. Introduction
It is well-known that the paper industry depends on four
major processes: (1): The chemical pulping Kraft or sulphate
pulping process; (2): The mechanical and chemo‒mechanical
pulping processes; (3): The recycled fiber process and (4): The
paper-making related processes. This industry often produces a
huge amount of waste material. The chemical pulping process
produces several residues including inorganic sludge (dregs
and lime mud), wood, straw or reed residues, sludge from
effluent treatment (inorganic material, fibers and biological
sludge), dust from boiler sand furnace. The by-products and
residues from mechanical and chemo‒mechanical pulping
include wood, straw and reed residues, fiber rejects and excess
sludge from an external biological waste water treatment [1,2].
The by‒products and residues from the pulp and paper
* Corresponding author.
E-mail address: hassandarweesh2000@yahoo.com (H.H.M. Darweesh).
All rights reserved. No part of contents of this paper may be reproduced or
transmitted in any form or by any means without the written permission of
ORIC Publications, www.oricpub.com.
industry are managed using several approaches including land
filling, incineration, use in cement plant and brickworks,
agricultural use and composting, anaerobic treatment,
recycling and others (Fig. 1). Owing to the high organic
contents and calorific values of these residues, incineration is
favored [2‒4]. Two types of organic residue are generated
during the bleached kraft pulp production (Fig. 1). The first is
from the initial milling operations and contains a coarse woody
part of raw material. This residue has low utilization potential
and usually landfill. The second is separated after the digestion
and washing operation by screening. These residues contain
short cellulose fibers and it could be utilized in the production
of moulded egg cartons. The second type of organic residue
was selected to use it in the brick production as a pore-forming
additive [2].
Moreover, the bulk density determines the thermal
conductivity [5]. One of the most conventional ways to
increase the insulation capacity of the brick is to generate
porosity in fired clay body. The addition of porosifers or pore
formers agents to a ceramic body can create pores. The most

2. 124 Darweesh and El-Meligy / Journal of Chemistry and Materials Research 1 (2014) 123–129
well-known pore formers used in clay brick manufacturing can
be divided into two groups (organic and inorganic). Sawdust,
styropor, paper sludge, coal and coke are some examples for
the organic pore formers. Perlite, diatomite, lime, pumice and
vermiculite are examples for the inorganic (mineral) type pore
formers.
Organic pore formers are generally cheaper than inorganic
sand also when they are burnt; it gives oversupply of heat to
the firing furnace. However, CO2 emission is the main
drawback of the organic pore formers. Inorganic pore formers
have less environmental problems but they may change the pl-
asticity of the clay system negatively and may increase the
water demand for the plasticity [6–9]. Organic process resid-
ues are extensively used as a pore former in brick industry.
Paper making sludge or residues is one of the best known
organic pore-forming residues. It contains both organic and
inorganic materials such as lime, kaolin or bentonite etc. [10].
It should be mentioned that owing to the high fiber content, the
paper‒making residues have now become indispensable in
many clay products for the stabilization of drying behaviour,
so that apart from its pore forming action, it may also be
regarded as a production auxiliary [8‒10]. However, bleached
Kraft pulp production, which is early stage of paper
production, also generates an important amount of organic
residue, which contains short cellulose fibers without any
mineral content, and this has not been utilized sufficiently yet.
The main objective of this study is to study the possibility
of using the straw and reed residues, which are the byproducts
from the bleached kraft pulp production, to produce clay
bricks. The physical abd mechanical as well as thermal
properties of the prepared bricks are studied. The results are
confirmed by SEM images to study the microstructure and the
new phases that formed on firing.
Fig. 1. Bleached Kraft Pulp Flow Chart and Process residues.
2. Experimental
2.1.Raw materials
The clay sample was taken from Toshka region (TC).
Toshka region is located on latitude 20°30‫־‬ N and longitude
31°53‫־‬ E at 250 km south of Aswan which was related to the
Upper Cretaceous age. The selected clay deposit is belonging
to El‒Dakhla Shale Formation. About 50 kg clay was collected
from the 85th km north of Aswan/Abu‒simple asphaltic road.
It is a dark yellowish grey. The clay sample was first dried and
then crushed, ground and quartered to have a representative
sample which was fine ground to pass 200 mesh sieves. The
Homra (H) which is the broken fired bricks was used as a
grog, i.e. to reduce the firing temperature. A Kraft pulp waste
(KPW) sample was also well‒ground before its use. The
chemical analysis of clay (TC) and Homra (H) samples using
the X‒ray fluorescence (XRF) technique is shown in Table 1,
while the suggested batch composition from the raw materials
is given in Table 2. The measured particle size distribution of
the used raw materials is illustrated in Table 3 as analyzed by a
Laser Size Distribution Analyzer (Master Sizer X 1.2b). Fig. 2
shows the SEM image of the dry KPW sample which
demonstrates that the thickness of the cellulose fibers is
between 2 and 8 µm and there are traces of organic and
inorganic materials on its surfaces.
Table 1 The chemical composition of raw materials, wt. %.
Materials Oxides T-Clay (TC) Homra (H)
L.O.I 9.72 ‒
SiO2 53.47 58.22
Al2O3 26.78 28.25
Fe2O3 3.99 8.16
CaO 0.60 0.79
MgO 1.38 0.46
MnO 0.03 ‒
K2O 1.18 1.46
Na2O 1.15 1.32
TiO2 1.12 1.34
SO3 ‒ ‒
P2O5 0.51 ‒
Cl‒
‒ ‒
Total 99.93 100
Table 2 The batch composition of raw materials, wt. %.
Materials Mixes TC H KPW
B0 95 5 0
B1 93 5 2
B2 91 5 4
B3 89 5 6
B4 87 5 8

3. Darweesh and El-Meligy / Journal of Chemistry and Materials Research 1 (2014) 123–129 125
Fig. 2. The SEM micrograph of KPW fiber composites after one day
of hydration.
2.2.Preparation of cement pastes
The kraft pulp waste (KPW) was dried to a constant weight
to ensure the correct amount of addition and then was
dissolved in water. The clay (TC) and homra (H) were then
added to it and mixed together. Six brick batches containing
TC, H and KPW were prepared as 100:0, 98:2, 96:4, 94:6 and
92:8 wt. % with symbols B0, B1, B2, B3 and B4,
respectively. The batches were mixed well in a gate ball mill
for one hour using the wet method, dried at 105 ºC for 72
hours and then ground to pass 200 mesh sieve to obtain the
same homogeneity of all batches. The Pfetterkorn test method
was used to measure the plasticity of the prepared brick
batches (B0‒B5) where 33 x 40 mm2
cylindrical specimens
were moulded. Five disc‒shaped samples of 2 cm diameter
and 2 cm thickness for the physical properties in terms of
water absorption, bulk density and apparent porosity, five rod-
shaped samples of 2.5 x 2.5 x 7 cm3
for dry and firing bending
or flexural strength and five cubes of 2.5 x 2.5 x 2.5 cm3
for
crushing strength were moulded. The molding of specimens
were carried out under a shaping pressure of 20 KN/mm2
using
water as a binder. After demoulding, the samples were let to
dry in air (23 ± 2 ºC) for 48 hours and then dried to a constant
weight at 105 ºC in a suitable oven to ensure the complete
elimination of the free water and to avoid the cracks during
firing. The firing process was carried out by a slow rate
furnace Mod. VECSTAR with a heating rate of 5 ºC/min.
The firing temperatures were 800, 900, 1000 and 1100 ºC with
one hour soaking time.
2.3.Densification Parameters
The densification parameters [11,12] in terms of water
absorption (WA), bulk density (BD) and apparent porosity
(AP) could be determined from the following equations:
W.A,% = (W1‒W2) / (W3) X 100 (1)
B. D, glcm3
= (W3) / (W1‒W2) (2)
A. P, % = (W1‒W3)/(W1‒W2) X 100 (3)
2.4.Mechanical properties
The mechanical properties in terms of flexural or bending
(BS) and crushing (CS) strengths [13,14]) of the fired units
could be calculated from the following equations:
B. S = 3 (PL) / 2 (b) (d) / 10.2 Mpa (4)
C.S = (D)/(L) x (w)/10.2 Mpa (5)
2.5.Dry and firing shrinkage
The dry and firing shrinkage [12,15] of the fired units
could be measured from the following equation:
F.S = (L -L) / (L ) X 100 % (6)
3. Results and Discusion
3.1.Characterization of raw materials
The physical properties of the clay (TC), Homra (H) and
kraft pulp waste (KPW0 samples as particle size distribution,
slaking time and nomenclature according to the Triangular
Folk Diagram [10,12,16] are summarized in Table 3. It is clear
that the TC sample is fine and has slaking or clay
characteristics and H is also fine but has no slaking or clay
characteristics. The KPW sample is not fine and is just fibers.
Fig. 3. The XRD patterns of Toshka clay sample (TC)
(ο: Quartz, ●: Kaolinite, ▲: Montmorillonite).
Fig. 4. The XRD patterns of Homra waste (H). (ο Quartz, A : Albite,
H: Hematite

4. 126 Darweesh and El-Meligy / Journal of Chemistry and Materials Research 1 (2014) 123–129
Table 3 The physical properties of raw materials.
Preparation Property TC H KPW
> 63 1.43 1.22 3.75
63‒16 1.68 1.46 2.16
16‒8 3.96 4.25 12.41
8‒2 9.14 10.32 17.34
< 2 (clay) 83.79
Nomenclature
according to Triangular
Folk Diagram
Clay silt fiber
Slaking Time H min.
1 30
H min.
2 15
H min.
‒ ‒
-190
-140
-90
-40
10
DTA,μV
-16
-14
-12
-10
-8
-6
-4
-2
0
2
0 200 400 600 800 1000 1200
Temperature, o
C
TGA,%
Exo
Fig. 5. The DTA - DTG thermograms of Toshka clay sample (TC).
The XRD patterns of the Toshka clay (TC) and Homra (H)
samples are shown in Figs. 3 and 4, respectively. The main
clay minerals are essentially the montmorillonite‒kaolinite
mixture and the quartz is the only non‒clay mineral impurity.
The DTA‒TGA analysis of the Toshka clay sample (TC) is
shown in Fig. 5. The two endothermic peaks at the temperature
range 100-120 and 500‒600 °C are due to the evaporation of
the absorbed and structural or hygroscopic water, respectively.
The endothermic peak at the temperature range of 800‒1000
°C is due to the calcination of calcite as follows:
CaCO3 → CaO + CO2 ↑ (7)
The endothermic peak at the temperature range 500‒650
°C is due to the conversion of kaolinite (AS2H2) to metakaolin
(A2S2), which in turn is converted to mullite phase (A2S2) at
980 °C as follows:
AS2H2 → AS2 → A2S2 (8)
3.2.Densification parameters
The densification parameters of the fired products in terms
of water absorption (WA), bulk density (BD) and apparent
porosity (AP) are plotted as a function of KPW content at
different firing temperatures in Figs. 6‒8, respectively.
Generally, as the firing temperature increased, the densific-
ation parameters of the fired products gradually improved
which in turn reflected positively on the mechanical properties
[12,16]. Both water absorption and apparent porosity decree-
sed as the firing temperature increased, while bulk density
increased. On the other side, as the KPW content increased up
to 4 wt. %, the water absorption and apparent porosity also
decreased while the bulk density increased. The same trend
was displayed with all firing temperatures. This is mainly
attributed to the formation of new crystalline phases resulting
from the thermal reactions during firing either through
decomposition and/or recombination changes [17,18], i.e.
during firing, the main crystalline phases in the green bodies
were completely replaced by the development of new
amorphous and crystalline phases [7].
Fig. 6. Water absorption of clay bricks containing 0, 2, 4, 6 and 8
wt.% KPW waste fired at 800‒1100 °C.
Fig. 7. Bulk density of clay bricks containing 0, 2, 4, 6 and 8 wt.%
KPW waste fired at 800‒1100 °C.

5. Darweesh and El-Meligy / Journal of Chemistry and Materials Research 1 (2014) 123–129 127
Fig. 8. Apparent porosity of clay bricks containing 0, 2, 4, 6 Fig. 9. Bending strength of clay bricks containing 0, 2, 4, 6
and 8 wt.% KPW waste fired at 800‒1100 °C. and 8 wt.% KPW waste fired at 800‒1100 °C.
Moreover, the existence of high amounts of fluxing oxides
(H) increased the rate of thermal reactions and liquid phase,
which in turn flows directly and settled inside the pore system
of the fired units. On solidification, a product of more compact
and glassy structure with a minimum porosity resulted. This
tends to improve and enhance all the densification parameters
of the produced ceramic units [16‒19]. The ceramic units
containing more than 6 wt. % KPW, the water absorption and
apparent porosity tended to increase, while bulk density decre-
ased, i.e. the all the densification parameters are adversely aff-
ected. The same property was also displayed even with the inc-
rease of firing temperature. This is essentially due to the crea-
tion of a more pore structure resulting from the evolution of
gases through the matrix of articles which results from the enh-
ancement of the thermal decomposition of some components
during firing [4], i.e. the addition of high amounts of KPW
into the ceramic bodies is undesirable due to its adverse action
on the physical properties of the resulted ceramic products.
3.3.Bending strength
The bending strength of the ceramic units containing
various ratios of KPW fired at different firing temperatures are
graphically represented in Fig. 9. As it is clear, the bending
strength increased with firing temperature. This is due to the
fact that as the firing temperature increases, the rate of densifi-
cation properties improves and enhances resulting in the form-
ation of a ceramic product having good mechanical properties
on cooling [12,19]. Therefore, it could be estimated that many
strengthening mechanisms of ceramic bodies took place
simultaneously during firing of the green bodies. Furthermore,
the good compaction of samples during moulding using a high
shaping pressure allows a suitable contact between the various
ingredients to react with each other forming new ceramic
phases which contribute to the high bending strength [2,5,20].
The bending strength of the ceramic products increased
with KPW content up to 4 wt. % due to that the presence of
(H) with the ceramic materials, increases the formation rate of
glassy phase and reduces its viscosity during sintering. On
cooling, the glassy matrix solidifies and cements all the unmel-
ted particles together. As a result, a ceramic product of high
mechanical properties could be obtained compared with those
containing no KPW, i.e. the presence of CaO, Fe2O3, Al2O3,
MgO and alkali oxides (Na2O and K2O) in (H) helps to form
sufficient quantities of liquid phase which promotes the
crystallization of Ca-rich phases, especially with mullite phase
[12,16]. On the other hand, as the KPW content increased
more than 6 wt. %, the bending strength of all units gradually
decreased even with the increase of firing temperature. This
may be due to that the higher amounts of KPW may be prevent
and hinder the suitable contact between the various ceramic
particles and those of KPW to react normally and freely with
each other. This in turn led to a reduction in the glassy or
liquid phase content. Hence, the new phases that responsible
for the enhancing of mechanical strength were reduced. In
addition, the migration of high rate of gases through the matrix
created a ceramic body with a high porosity. So, the
mechanical properties diminished [2,5,6,12]. Accordingly, the
optimum ceramic products are those containing 4 wt. % KPW.
3.4.Crushing strength
The crushing strength of the ceramic units containing
various ratios of KPW (2‒8 wt. %) fired at different firing

6. 128 Darweesh and El-Meligy / Journal of Chemistry and Materials Research 1 (2014) 123–129
temperatures are plotted as a function of KPW content in
Fig.10. The crushing strength of the prepared ceramic units
increased with firing temperature up to 1100 ºC. This is due to
the fact that the presence of (H) increases the formation of
glassy or liquid phase and reduces its viscosity during
sintering. On cooling, the glassy matrix solidifies and cements
all the unmelted particles together. As a result, a ceramic
article of high mechanical properties could be produced
compared with those of the blank, i.e. the increase of glassy
phase which improves and enhances the thermal reactions
between the various ingredients. As the liquid phase increased
the total porosity decreased to a large extent which in turn will
enhance the bulk density and increased the mechanical
properties. This led to the formation of well‒developed
crystals [12,19,20]. On the other side, the presence of KPW
fibers which converted to ash on firing increases the crushing
strength up to 4 wt % KPW content. But as the KPW content
increased more than 4 wt. %, the crushing strength of all
ceramic products gradually decreased even with the increase
of firing temperature up to 1100 ºC. This may be attributed to
that the higher amounts of KPW prevent and hinder the
suitable contact between the various ceramic particles to react
freely with each other and with those of KPW and moreover
the increase of KPW content on the expense of the clay
affected negatively on the strength due to the deficiency of the
main ceramic material [12,21,22]. This in turn led to a
reduction in the rate of the formed glassy or liquid phase. So,
the new phases that responsible for the enhancing of
mechanical strength were reduced. Also, the migration of
gases through the matrix created a ceramic body with high
pore structure which reflected negatively on the mechanical
properties [12,19]. Therefore, the high amounts of KPW fibers
must be avoided. Hence, the results of densification properties
of all samples are in a good agreement with those of mechani-
cal strength. Accordingly, the optimum ceramic units are those
containing 4 wt. % KPW fired at 1100 ºC.
3.5.Dry and firing shrinkages
Fig. 11 shows the dry and firing shrinkages of the ceramic
products containing various ratios of KPW fired at different
firing temperatures. The dry shrinkage of all ceramic units was
equal to zero, i.e. all dimensions of the prepared green ceramic
units are unchanged on drying. On firing, the firing shrinkage
increased slightly at 800 and 900 ºC and increased forward up
to 1100 ºC. The same trend was displayed by all samples [4].
The ceramic units containing no KPW exhibited the lowest
values of firing shrinkage and those containing 10 wt. % KPW
achieved the highest values nearly at all firing temperatures.
The lower values of firing shrinkage are mainly due to the
removal of residual and combined water contents as well as the
conversion of KPW fibers to ashes which evidently diminish
its volume, but the higher values are due to the migration of
gases from the dissociation of carbonates (CO2↑) and sulfates
(SO3↑) [12] in addition to the conversion of KPW to ashes,
respectively. Moreover, the presence of larger amounts of CaO
and alkali oxides in KPW tends to lower the melting point of
the fired units which contributes to the formation of large
amounts of glassy phase. This is the essential cause of the
sharp increase of the total firing shrinkage of ceramic bodies
containing 8-10 mass % KPW. However, the firing shrinkage
of ceramic bodies containing 8‒10 wt. % KPW lies in the
permissible limits in all standard specifications. Accordingly,
the optimum base batch is that containing 4 wt. % KPW. So,
the dry and firing shrinkage of ceramic bodies are also in a
good agreement with those of densification and mechanical
properties.
Fig. 10. Crushing strength of clay bricks containing 0, 2, 4, 6 Fig. 11. Dry and firing shrinkage of clay bricks containing 0, 2,
and 8 wt.% KPW waste fired at 800-1100 °C. 4, 6 and 8 wt.% KPW waste fired at 800-1100 °C.

7. Darweesh and El-Meligy / Journal of Chemistry and Materials Research 1 (2014) 123–129 129
4. Conclusions
The densification parameters in terms of Water absorption,
apparent porosity and bulk density as well as mechanical
properties in terms of bending and crushing strengths are
improved and enhanced with firing temperature up to 1100 ºC
and also with the partial substitution of the kraft pulp waste
(KPW) up to 4 wt. % and then adversely affected. The dry
shrinkage is nearly unchanged, while the firing shrinkage
slightly increases with KPW content and firing temperature.
The ceramic products with 4 wt. % KPW waste recorded the
best results at all firing temperatures compared with the others,
particularly at 1100 ºC. Accordingly, the optimum amount of
KPW substitution is 4 wt. % and the optimum firing temperat-
ure is 1100 ºC. This clearly points out that the ceramic
products fired at lower temperatures (800‒900 ºC) are suitable
for porous light‒weight bricks, while those fired at high
(1000‒1100 ºC) are not favorable because the dimensional
stability are not good due to the surface bloating appearance.
Thus, the optimum ceramic batch is that containing 4 wt %
KPW waste fired at all firing temperatures specially 1100 ºC.
The bricks fired at higher firing temperatures (1100 ºC) are not
recommended.
References
[1] United Nations Economic and Social Council, Report Number:
Executive summary of the status report on the management of
byproduct/residue containing persistent organic pollutants. EB. Air /
Wg. 5 / 9, 2001, 12–13.
[2] Demir, I., Baspınar, M.S. and Orhan, M. (2005). Utilization of kraft
pulp production residues in clay brick production. J. Building and
Environment, 40, 1533–1537.
[3] Shao, Y., Qui, J. and Shah, S.S. (2001). Microstructure of extruded
cement bonded fiberboard. Cem. Concr. Res., 31(1), 153–61.
[4] Seminar, I.Z.F. (1994). Brick‒making raw materials‒properties,
treatment, product quality Part 1. Ziegelindustrie International, 2(11),
779–90.
[5] Schmidt-Reinholz, Ch. (1990). Suggestions for the reduction of bulk
density through additives. Tile and Brick International, 6(3), 23–7.
[6] Junge, K. (2000). Additives in the brick and tile industry.
Ziegelindustrie International, 8(12), 25–39.
[7] Krebs, S., Mörtel, H. (2001). The use of secondary pore-forming agents
in brick production. Tile and Brick International, 15(1), 23–27.
[8] Junge, K. (2001). Oversupply of energy due to combustible additives.
Ziegelindustrie International, 9(12), 10–14.
[9] Dondi, M., Marsigli, M., Fabbri, B. (1997). Recycling of industrial and
urban wastes in brick production—a review. Tile and Brick
International, 13(1), 218–225.
[10] Junge, K. and Pauls, N. (1994). Pore forming of lightweight, vertical
coring bricks and blocks ecological evaluation of the production
process. Ziegelindustrie International Jahrbuch, 90–96.
[11] ASTM-Specification. (1980). Standard Test Method for water
absorption, bulk density, apparent porosity and specific gravity of
whiteware products”, Part 17, C373-72, 159-167, Reappr. pp. 308-309.
[12] Darweesh, H.H.M., Wahsh, M.M.S., Negim, E.M. (2012). Densification
and Thermomechanical Properties of Conventional Ceramic Composites
Containing Two Different Industrial Byproducts. Amer.-Eurasian
Journal of Scientific Research, 7 (3), 123-130.
[13] ASTM- Designation. (2002). Standard Test Method for flexural strength
of concrete using simple Beam with Third-Point Loading. C78-02, pp.
1-3.
[14] ASTM- Specification. (1993). Standard Test Method for cold crushing
strength of dimensional stones. C170-90, Reappr. pp. 828-830.
[15] ASTM- Specification. (1980). Standard Test Method for shrinkage of
ceramic whiteware clays after drying and firing. Part 17, C326-32-76,
Reappr. pp. 266-267.
[16] Darweesh, H.H.M., Awad, H.M., Tawfik, A. (2011). Red Bricks from
Dakhla Formation Clay - Tushka area-Incorporated with some Ind.
Wastes or byproducts” Industrial Ceramics, 31(3), 201-207.
[17] El-Alfi E.A., Radwan, A.M., Darweesh, H.H. (2004). Effect of sand as
non-plastic material on ceramic properties of clay bricks. InterCeram
(Intern. Cer. Review), 53(5), 330-333.
[18] Darweesh, H.H. (2001). Building materials from siliceous clay and low
grade dolomite rocks. Ceramic International, 27, 45-50.
[19] Turgut, P. and Algin, H.M. (2007). Limestone dust and wood sawdust
as brick material. Building and Environment, 42, 3399-3403.
[20] Sabrah B.A. and Ebied, E.A. (1985). Interbrick, A Verlag Schmid
Publ., Inten. J. Structural Clay Ind., 1(5), 29-33.
[21] Chiang, Y.M., Birnie, D.P., Kingery, W.G. (1997). Physical Ceramics-
Principals for Ceramic Science and Engineering. 3rd edn., John Wiley
and Sons, Lehigh Press. Inc., USA.
[22] Turgut, P. (2008). Properties of masonry blocks produced with
limestone sawdust and glass powder. Construction and Building
Materials, 22, 1422-1427.