A study of pressure influences of phosphogypsum based bricks

International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 3, May - June (2013), © IAEME
143
A STUDY OF PRESSURE INFLUENCES OF PHOSPHOGYPSUM-
BASED BRICKS
Lamia Bouchhima(1), Mohamed Jamel Rouis (2), Mohamed Choura (3)
Unit of research environmental geotechnique and civil materials, Institute of the engineers of
Sfax, Tunisia
ABSTRACT
Housing is a great problem in today’s world. The most basic building material for
construction of houses is the usual burnt clay brick. A significant quantity of fuel is utilized
in making these bricks. Also, continuous removal of topsoil, in producing conventional
bricks, creates environmental problems. A feasibility study was undertaken on the production
of phosphogypsum-wade sand based bricks to build houses economically by utilizing
industrial wastes. All full bricks were made on a bench model, semiautomatic press, to
produce bricks under a static compaction of 15 and 20 MPa. The compressive strength,
flexural strength water absorption and density of these bricks are investigated. It is observed
that these bricks have sufficient strength for their use in housing development. Tests were
also conducted to study the pressure influences of bricks. The results suggest that
compressive and flexural strength increase with pressure. Tests were also conducted to study
behavior immersion of phosphogypsum- wade sand based bricks. The results suggest that
behavior immersion of bricks improves with increasing pressure.
Keywords: phosphogypsum-wade sand based bricks; strength; pressure.
1. INTRODUCTION
Phosphogypsum (calcium sulfate) is a naturally occurring part of the process of
creating phosphoric acid (H3PO4), an essential component of many modern fertilizers. For
every tonne of phosphoric acid made, from the reaction of phosphate rock with acid,
commonly sulfuric acid, about 3 t of phosphogypsum are created. There are three options for
managing phosphogypsum: (i) disposal or dumping, (ii) stacking, (iii) use-in, for example,
agriculture, construction, or landfill.The need to reduce solid waste volume has caused
scientists to invent new construction materials produced using waste materials.
INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND
TECHNOLOGY (IJCIET)
ISSN 0976 – 6308 (Print)
ISSN 0976 – 6316(Online)
Volume 4, Issue 3, May - June (2013), pp. 143-154
© IAEME: www.iaeme.com/ijciet.asp
Journal Impact Factor (2013): 5.3277 (Calculated by GISI)
www.jifactor.com
IJCIET
© IAEME

144
In Tunisia, for several years, a set of phosphoric acid production factories have
produced PG in large great quantities (approximately 10 million tons per year [1]. Currently,
the PG is stored into piles in the vicinity of the factory, by dry or wet process. The storage of
PG causes the pollution of the water table and the soils by acid and heavy metals infiltrations.
Its valorization leads to environmental protection and to minimization of the storage costs.
Several researchers had studied the use of PG in various fields. The PG was treated to be used
in the plaster manufacture. It has been found that the PG is suitable for making good quality
plaster showing similar proprieties to natural gypsum plaster [2-4]. This field is advantageous
for the countries which do not have natural quarries such as Japan and India. The PG has
been sought also to be used in agriculture [5]. It is as effective as the crushed natural gypsum.
However, the quantities used are limited and moreover the health standards became
increasingly restrictive. But the most interesting use of the PG is for the cement
manufacturing: either by natural gypsum substitution (about 5%), which will play the role of
a set retarder [6-7], or to reduce the clinkerization temperature [8]. The PG was also used in
soil stabilization [9]. Finally phosphogypsum PG has been studied to be used in hollow
blocks [10] and light brick [11].
In Tunisia, the PG was studied to be used in similar fields. The most successful
application so far is in the manufacture of cement; by substitution of the gypsum. The
obtained product is known under the name of cement ultimo. It showed good performances
but the used quantity is low [12-13]. Moussa et al [14] had studied the possibility of the use
of the PG in the embankments. The PG is studied in order to use it like a fill. This study
showed a behavior to the compaction not similar to that of a soil. Furthermore, the fill
showed also a continuous settlement because of the PG solubility. Moreover, Kuryatnyk and
Angulski- Ambroise- Pera [15] have employed the Gabes and Skhira PG to be used as a
hydraulic binder. But formation of ettringite led to cracking and strength loss. Finally, Sfar
[16] has explored the PG for a road use. The study proposed the following formulation:
46.5% of PG, 46.5% of sand and 7% of cement. But this study was conducted in the Tunisian
south region, where the rainfall is low.
In this paper compressive strength, flexural strength water absorption, density and
behavior immersion of phosphogypsum- wade sand-lime-cement bricks are investigated. The
influences of pressure on these characteristics are studied.
2. EXPERIMENTAL PROGRAM.
2.1. Chemical composition
The chemical analyses, considered most relevant to the prospect use in commercial
brick making, were undertaken on the PG. The results of these analyses are presented in
Table 1. The PG is primarily (about 77%) made up of calcium sulfate (CaSO4). The
remaining components are present at low percentage. It should be noted that the pH of PG
samples has been found to be around 2.9, indicating a high acidity of the PG.
Table1. Chemical composition of phosphogypsum
Elements (%)
CaO SO3 P2O5 F SiO2 Fe2O3 Al2O3 MgO
Ignition
loss at
1000°C
32.8 44.4 1.69 0.55 1.37 0.03 0.11 0.007 22.3

145
2.2. Preparation of phosphogypsum, wade sand, lime-cement bricks
The mix proportions of phosphogypsum, wade sand (WS), lime and cement (cement
HRS 42.5) for bricks are given in table 2. The mix proportions are given in terms of dry
weights of the ingredients. The water content of Phosphogypsum-wade sand-lime mixtures
was fixed to 4 %. Bricks produced with more than 4 % showed cracks after fabrication due to
excessive water.
Table 2. Mix proportions of WS-NHL-C-PG full bricks
Mix désignation
Constituant materials (Weight %)
Phosphogypsum Sand (WS) Cement Lime
M-1 60 32 5 3
M-2 60 29.5 7.5 3
M-3 60 27 10 3
M-4 70 22 5 3
M-5 70 19.5 7.5 3
M-6 70 17 10 3
M-7 80 12 5 3
M-8 80 9.5 7.5 3
M-9 80 7 10 3
The dry phosphogypsum was sieved through 1 mm sieve. The weighed quantity of
phosphogypsum, wade sand, lime and cement were first thoroughly mixed in dry state for a
period of 10 minutes to uniform blending. The required water was then gradually added and
the mixing continued for another 5 min.
All solid bricks were made on a bench model, semiautomatic press having a capacity of 25
tons, to produce bricks of 51×95×203 mm in size under a static compaction of 15 and
20MPa.
2.3. Testing of bricks
All bricks were dried to the free air for a period of 28, 56 and 90 days. Compressive
strength, density, water absorption, and leaching tests of bricks from different mixes of
phosphogypsum, wade sand, lime and cement with available mixing water content were
determined.
Compressive strength of the units was determined according ASTM C67 [17]. Test
bricks consist of a half brick with full height and width. Flexural strength tests on the bricks
were performed according to ASTM C 67 [17]. Test specimens were taken as full-size brick
units.
Rate of absorption is an important property of brick because it affects mortar and
grout bond. If the rate of absorption is too high, brick will absorb moisture from the mortar or
grout at a rapid rate, thus impairing the strength and extend of bend.
Water absorption was determined according to ASTM C67 [17]. The test specimens
were consisted of half bricks. Five specimens were tested. This test was determined on bricks
tested after 28 days of casting.
In order to determine the density of each brick, dry bricks were weighed accurately
and their volumes were measured.

146
To simulate the action of the weather, the bricks are soaked in water for two days [18]
after 90 days of treatment. The effect of immersion on compressive strength and flexural
strength has been studied.
The leaching tests had been performed according to the French norm NF EN 12457-3
[19] at an ambient temperature (20 ± 5°C). The specimens (three different samples for each
mix-design) were crushed and an amount of 0.175 kg was taken to be analyzed. The distilled
water was added to obtain a liquid/solid ratio of 10 l/kg.
The leaching test was determined on bricks tested after 28 days of casting.
3. TEST RESULTS AND DISCUSSION
3.1. Dry density
The densities of WS-NHL-C-PG full bricks are shown in table 3. These densities
range from 1434.5 to 1760.5 kg/m3
. Therefore the WS-NHL-C-PG full bricks have high
density. We note that the densities of bricks increases with the phosphogypsum and cement
additions. Also densities of all full bricks increase with increasing pressure.
Table 3. Dry densities (kg/m3
) of WS-NHL-C-PG full bricks versus pressure
Mix design
Dry densities (kg/m3
)
15MPa 20MPa
28 days 56 days 90 days 28 days 56 days 90 days
M1 1434.5 1495 1526.5 1523 1575 1590
M2 1499 1545 1560.5 1562.5 1600 1618.5
M3 1559.5 1601 1620 1589.5 1635.5 1650
M4 1520.5 1538 1544 1550.5 1588 1600
M5 1560.5 1585 1593 1595 1620.5 1630
M6 1592 1620.5 1630 1620 1646 1660.5
M7 1587 1650 1691.5 1602 1675.5 1706
M8 1614.5 1690 1714.5 1625.5 1690.5 1724
M9 1667 1750 1783 1670 1760.5 1760.5
3.2. The 24-h cold water absorption of studied bricks
The water absorption is a principal factor for the durability of the product and its
behavior to natural environment. Table 4 presents the results of the water absorption for the
selected percentages of the bricks. It was observed that the water absorption of bricks
decreased with the increase of pressure. Also, it was observed that the values obtained were
favorable when compared with those of clay bricks (0 to 30%) [20]. the addition of pressure
produces a decrease in the internal pore size. Thus, the brick becomes less porous causing an
increase in the water absorption.

147
Table 4. Water absorption 24 h cold water of WS-NHL-C-PG full bricks
Mix designation Water absorption
after 24 hr cold water
(%) (15MPa)
Water absorption
after 24 hr cold water
(%) (20MPa)
M1 28.9 26.97
M2 28.4 26.09
M3 27.4 24.29
M4 28 25.56
M5 27.3 24.05
M6 26 23.06
M7 27.5 24.5
M8 26 23.04
M9 25 22.33
3.3. Compressive strength of studied bricks
The results, obtained as an average of measurements performed on three specimens,
are shown in table 5. The BS6073-Part 1 [21] (require minimum compressive strengths of 7.0
MPa and 11.7 MPa after a 28-day curing period for load-bearing concrete masonry units. All
mixtures described in this study satisfied the standard for compressive strength.
For all the studied cases, the strength of the 90 days cured full bricks was higher than 10.3
MPa, which is the minimum strength indicated by the standards [22]. Cement and lime as a
source of reactive silica and alumina are given to silicate and aluminate hydrates, which are
responsible for the development of strength. These Figures show also increase in the strength
with the pressure. The maximum of compressive strength is reached with 20 MPa.
This result confirms the water absorption test outcome, where it has been indicated that the
brick becomes less porous causing an increase in the mechanical strength.
Table 5. Compressive strength (MPa) of WS-NHL-C-PG full bricks versus pressure
Mix design
Compressive strength (MPa)
15MPa 20MPa
M1 9.04 10.526 10.78 11.24 12.028 12.316
M2 10.182 11.364 11.647 12 13.473 13.747
M3 11.278 12.1 12.366 13 13.955 14.247
M4 10 10.94 11.2 11.718 12.41 12.7
M5 10.406 11.547 11.811 12.45 13.35 13.805
M6 11.46 12.4 12.634 13.63 14.289 14.523
M7 10.441 11.25 11.42 12.179 12.9 13.2
M8 11.461 12 12.2 13.4 14.331 14.63
M9 11.964 12.69 12.874 14.21 14.765 15.01
3.4. Flexural strength of studied bricks
are shown in table 6. The code ASTM does not specify a requirement for flexural strength.

148
However the values obtained were favorable when compared with the minimum flexural
strength required by BS6073-Part 1 (0.65 MPa) after a 28-day curing period wich was
surpassed by all the samples.
These Figures show also increase in the flexural strength with the pressure. The maximum of
compressive strength is reached with 20 MPa.
Table 6. Flexural strength (MPa) of WS-NHL-C-PG full bricks versus pressure
Mix design
Flexural strength (MPa)
15MPa 20MPa
M1 5.59 5.915 6.015 7.65 7.9 8
M2 5.65 6.053 6.203 7.79 8.062 8.198
M3 5.8 6.118 6.319 7.93 8.24 8.342
M4 5.68 6 6.2 7.73 8.12 8.267
M5 5.79 6.19 6.323 7.85 8.27 8.36
M6 5.9 6.3 6.439 7.97 8.385 8.532
M7 5.79 6.115 6.316 7.82 8.175 8.386
M8 5.85 6.25 6.464 8.08 8.503 8.723
M9 5.98 6.356 6.57 8.18 8.606 8.846
3.5. Behavior immersion of bricks
3.5.1. Compressive strength of full bricks after 2 days immersion
are shown in table 7. The loss of compressive strength after 2 days of immersion in water is
given in figs.1-3. It is observed that loss in compressive strength decrease with
phosphogypsum and cement content. So bricks with more phosphogypsum and cement have
better compressive strength after 2 days immersion.
Also, we note a decreasing of loss in compressive strength with increasing pressure. So the
behavior immersion of bricks becomes better with increasing pressure.
Table 7 Compressive strength of WS-NHL-C-PG full bricks after 2 days of immersion in
water
Mix design
Compressive strength after 2 days of
immersion in water (MPa)
15MPa 20MPa
M1 8,55 10,38
M2 9,58 11,98
M3 10,38 12,67
M4 9,02 10,79
M5 9,81 12,1
M6 10,68 13
M7 9,33 11,29
M8 10,22 12,84
M9 10,95 13,49

International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 3, May
Fig.1 Loss in compressive strength of WS
0
5
10
15
20
25
5
lossincompressivestrength(%)
0
5
10
15
20
5
Online) Volume 4, Issue 3, May - June (2013), © IAEME
149
Loss in compressive strength of WS-NHL-C-PG full bricks (phosphogypsum=60%)
7.5 10
cement (%)
15MPa
20MPa
7.5 10
cement (%)
15MPa
20MPa
June (2013), © IAEME
PG full bricks (phosphogypsum=60%)
(phosphogypsum=70%)
15MPa
20MPa
15MPa
20MPa

3.5.2. Flexural strength of full bricks after 2 days immersion
are shown in table 8. The loss of compressive strength after 2 days of immersion in water is
given in figs.4-6. It is observed that loss in
and cement content. So bricks with more phosphogypsum and cement have bette
strength after 2 days immersion.
Also, we note a decreasing of loss in
decreasing is rather significant than decreasing in loss of compressive strength with pressure.
Table8. Flexural strength of WS
Mix design
M1
M2
M3
M4
M5
M6
M7
M8
M9
0
5
10
15
20
5
150
. Flexural strength of full bricks after 2 days immersion
hown in table 8. The loss of compressive strength after 2 days of immersion in water is
6. It is observed that loss in flexural strength decrease with phosphogypsum
and cement content. So bricks with more phosphogypsum and cement have bette
Also, we note a decreasing of loss in flexural strength with increasing pressure.
rather significant than decreasing in loss of compressive strength with pressure.
WS-NHL-C-PG full bricks after 2 days of immersion in water
Flexural strength after 2 days of immersion in
water (MPa)
15MPa 20MPa
3,75 6,68
4 6,96
4,46 7,49
4 7,05
4,28 7,23
4,7 7,71
4,22 7,32
4,5 7,84
4,92 8,18
7.5 10
cement (%)
15MPa
20MPa
hown in table 8. The loss of compressive strength after 2 days of immersion in water is
strength decrease with phosphogypsum
and cement content. So bricks with more phosphogypsum and cement have better flexural
strength with increasing pressure. The
rather significant than decreasing in loss of compressive strength with pressure.
PG full bricks after 2 days of immersion in water
Flexural strength after 2 days of immersion in
15MPa
20MPa

Fig.4 Loss in flexural strength of WS
0
5
10
15
20
25
30
35
40
5
lossinflexuralstrength(%)
0
5
10
15
20
25
30
35
40
5
151
Loss in flexural strength of WS-NHL-C-PG full bricks (phosphogypsum=60%)
7.5 10
cement (%)
15MPa
20MPa
7.5 10
cement (%)
15MPa
20MPa
15MPa
20MPa
15MPa
20MPa

3.5. Leaching tests
The average values of the leachi
concentrations of the selected metal species, i.e., Cd, Cu, Zn, Ni, Pb, and Cr, for
design, were well below the regulatory limits. Thus, this result
brick specimens can be considered as non hazardous materials.
Table 9. Leaching test results, in mg/kg for L/S = 10 l/kg (15MPa)
Eléments M1 M2 M3 M4
Cr 0.09 0.087 0.86 0.08
Ni 0.088 0.083 0.073 0.079
Zn 0.068 0.066 0.064 0.064
Pb 0.12 0.098 0.093 0.1
Cu 0.15 0.1 0.098 0.12
Cd 0.08 0.077 0.072 0.07
0
5
10
15
20
25
30
35
5
152
The average values of the leaching test are presented in Table 9 and 10
concentrations of the selected metal species, i.e., Cd, Cu, Zn, Ni, Pb, and Cr, for
the regulatory limits. Thus, this result indicates that PG amended
brick specimens can be considered as non hazardous materials.
Leaching test results, in mg/kg for L/S = 10 l/kg (15MPa)
M4 M5 M6 M7 M8 M9
Limit
values
acceptable
as inert
0.08 0.078 0.08 0.068 0.069 0.063 4
0.079 0.074 0.066 0.074 0.07 0.068 0.4
0.064 0.062 0.06 0.06 0.058 0.06 4
0.1 0.095 0.09 0.095 0.093 0.09 0.5
0.12 0.098 0.096 0.099 0.096 0.094 2
0.07 0.05 0.045 0.055 0.041 0.04 0.04
7.5 10
cement (%)
15MPa
20MPa
9 and 10. The
concentrations of the selected metal species, i.e., Cd, Cu, Zn, Ni, Pb, and Cr, for all mix-
indicates that PG amended
Leaching test results, in mg/kg for L/S = 10 l/kg (15MPa)
Limit
values
acceptable
as inert
Limit
values
acceptable
as non
hazardous
50
10
50
10
50
1
15MPa
20MPa

153
Table 10. Leaching test results, in mg/kg for L/S = 10 l/kg (20MPa)
Eléments M1 M2 M3 M4 M5 M6 M7 M8 M9
Limit
values
acceptable
as inert
Limit
values
acceptable
as non
hazardous
Cr 0.069 0.066 0.65 0.059 0.056 0.048 0.046 0.037 0.031 4 50
Ni 0.066 0.061 0.051 0.057 0.052 0.044 0.052 0.049 0.046 0.4 10
Zn 0.046 0.044 0.042 0.042 0.04 0.039 0.038 0.036 0.034 4 50
Pb 0.095 0.09 0.088 0.091 0.089 0.087 0.088 0.087 0.085 0.5 10
Cu 0.1 0.095 0.093 0.09 0.092 0.089 0.088 0.086 0.079 2 50
Cd 0.06 0.057 0.052 0.05 0.03 0.02 0.035 0.02 0.02 0.04 1
4. CONCLUSION
Based on the experimental investigation reported in this paper, following conclusions are
drawn:
(1) The WS-NHL-C-PG bricks manufacturing a static compaction of 15 and 20 MPa have
sufficient strength and have potential as a replacement for load-bearing concrete masonry
units and conventional full clay bricks grade NW.
(2) Phosphogypsum has more pronounced binding action than wade sand.
(3) The increase of the pressure resulted in increase in the mechanical strengths of bricks.
(4) The increase of the pressure resulted in decrease in water absorption of bricks.
(5) The increase of the percentages of PG and cement resulted in increase in the compressive
and flexural strength of full bricks after 2 days of immersion in water.
(6) The increase of pressure resulted in increase in the compressive and flexural strength of
full bricks after 2 days of immersion in water.
REFERENCES
[1] Sfar Felfoul H, Clastres P, Carles GA, Ben Ouezdou M. (2002) Amelioration des
caracteristiques du phosphogypse en vue de son utilisation en technique routiere.
Dechets Sci Tech; vol. 28, pp. 21–5 [in French].
[2] Singh M. (2002) Treating waste phosphogypsum for cement and plaster manufacture.
Cem Concr Res; vol. 32; No. 7, pp. 1033–8.
[3] Singh M. (2003) Effect of phosphatic and fluoride impurities of phosphogypsum on the
properties of selenite plaster. Cem Concr Res; vol. 33; No. 9, pp. 1363–9.
[4] Singh M. (2005) Role of phosphogypsum impurities on strength and microstructure of
serenity plaster. Constr Build Mater; vol. 19; No. 6, pp. 480–6.
[5] Mullins GL, Mitchell CC. (1990) Wheat forage response to tillage and sulfur applied as
PG. In: Proceedings of the third international symposium on PG, Orlando, USA, vol. I.
Publication FIPR no. 01-060-083; pp. 362–75.

154
[6] Potgieter JH, Potgieter SS, McCrindle RI, Strydom CA. (2003) An investigation into
the effect of various chemical and physical treatments of a South African
phosphogypsum to render it suitable as a set retarder for cement. Cem Concr Res. 33,
pp. 1223–7.
[7] Altun IA, Sert Y. (2004) Utilization of weathered phosphogypsum as set retarder in
Portland cement. Cem Concr Res; vol.34, pp. 677–80.
[8] Kacimi L, Simon-Masseron A, Ghomari A, Derriche Z. (2006) Reduction of
clinkerization temperature by using phosphogypsum. J Hazard Mater; vol. B137, pp.
129–37.
[9] Degirmenci N, Okucu A, Turabi A. (2007) Application of phosphogypsum in soil
stabilization. Build Environ; vol. 42, pp. 3393-8.
[10] Sunil K. (2003) Fly ash-lime-phosphogypsum hollow blocks for walls and partitions.
Building and Environment; vol. 38, pp.291-295.
[11] Abalı YK, Yurdusev MA, Zeybek MS, Kumanlıog˘lu AA. (2007) Using PG and boron
concentrator wastes in light brick production. Constr Build Mater ; vol. 21, pp. 52–6.
[12] Karray MA, Mensi R. (2000) Etude de la Deformabilite des Poutrelles en Beton Arme a
base du Ciment Ultimax. Ann Batiment Travaux Publics;2, pp. 5–14 [in french].
[13] Charfi FF, Bouaziz J, Belayouni H. (2000) Valorisation du phosphogypse de Tunisie en
vue de son utilisation comme substituant au gypse naturel dans la fabrication du ciment.
[14] Moussa D, Crispel JJ, Legrand CL, Thenoz B. (1984) Laboratory study of the structure
and compactibility of Tunisian phosphogypsum (Sfax) for use in embankment
construction. Resour Conserv; vol. 11; No. 2, pp. 95–116 [in French].
[15] Kuryatnyk T, Angulski da Luz C, Ambroise J, Pera J. (2008) Valorization of
phosphogypsum as hydraulic binder. J Hazard Mater; vol. 160, No. 2–3, pp. 681–7.
[16] Sfar Felfoul H. (2004) Etude du phosphogypse de Sfax (Tunisie) en vue d’une
valorisation en technique routiere. PhD thesis, Department of Civil Engineering,
National Engineering School of Tunis/INSA Toulouse.
[17] Ahmadi BH. (1989) Use of high strength by product gypsum bricks in masonry
construction. PhD dissertation, University of Miami, Coral Gables, Florida, USA. 245p.
ASTM international: C62-08, Standard specification for building brick: Solid Masonry
Units Made from Clay.
[18] FEKI N., (1991) : Utilisation du phosphogypse en assises de chaussées. Projet de fin
d’études de la filière longue, Génie Géologique, ENIS, 93 p.
[19] AFNOR. Lixiviation (2002) – Essai de conformite pour Lixiviation des dechets
fragmentes et des boues. NF EN 12457-3; [in French].
[20] Deboucha S, Hashim R, Aziz AA. (2011) Engineering properties of cemented peat
bricks Scientific Research and Essays Vol. 6. No. 8, pp. 1732-1739.
[21] BS 6073: Part 1: precast concrete masonry units, Part 1. Specification for precast
concrete masonry units. British Standards Institution, 1981.
[22] ASTM international: C62-08, Standard specification for building brick: Solid Masonry
Units Made from Clay (2008) 4p.
[23] Lamia Bouchhima, Mohamed Jamel Rouis and Mohamed Choura, “Behavior
Immersion of Phosphogypsum- Crushing Sand Based Bricks”, International Journal of
Advanced Research in Engineering & Technology (IJARET), Volume 4, Issue 4, 2013,
pp. 96 - 106, ISSN Print: 0976-6480, ISSN Online: 0976-6499.

A study of pressure influences of phosphogypsum based bricks

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (19)

Similaire à A study of pressure influences of phosphogypsum based bricks

Similaire à A study of pressure influences of phosphogypsum based bricks (20)

Plus de IAEME Publication

Plus de IAEME Publication (20)

Dernier

Dernier (20)

A study of pressure influences of phosphogypsum based bricks