Construction and Building Materials 37 (2012) 738–745
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Construction and Building Materials
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Assessment of compressed earth blocks made in Spain: International durability tests
Jaime Cid-Falceto a,⇑, Fernando R. Mazarrón b, Ignacio Cañas a
a
b
Construction and Rural Roads Department, E.T.S.I. Agrónomos, Polytechnic University of Madrid, Avda. Complutense s/n, 28040 Madrid, Spain
Rural Engineering Department, E.T.S.I. Agrónomos, Polytechnic University of Madrid, Avda. Complutense s/n, 28040 Madrid, Spain
h i g h l i g h t s
" We study the durability against rain of compressed earth blocks.
" We analyze the usefulness of test procedures proposed in the international normative.
" The lack of unified criteria in the tests produces differences in the results obtained.
" Spanish CEB are fit for exterior and/or interior walls depending on stabilization.
" This analysis could be a reference in the writing of future normative documents.
a r t i c l e
i n f o
Article history:
Received 20 December 2011
Received in revised form 25 July 2012
Accepted 11 August 2012
Available online 13 September 2012
Keywords:
Compressed earth block
Durability
Erosion test
Standards
Construction material
a b s t r a c t
This research studies the durability against rain of the most industrialized construction material based on
unbaked earth: compressed earth blocks (CEBs). The test procedures will be those ones proposed in the
international normative (44 normative documents studied), analyzing the usefulness of these tests. The
lack of unified criteria in the tests produces differences in the results obtained depending on the method
used. Spanish stabilized CEB are fit for both interior faces and exterior walls, while non-stabilized CEB are
just adequate to be used in exterior walls by applying a protection. This analysis could be a reference in
the writing of future normative documents for all the world.
Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction
1.1. Compressed earth blocks
Constructions based on unbaked earth date back since more
than 9000 years ago [1]. Compressed earth block (CEB) has become
more common in the last few years as an earth construction system [2], proving to be an industrialized material, besides its traditional value as an element of self-construction.
CEB includes all the variations of this product, whether or not
the earth is stabilized [3]. Although throughout the literature different designations are used, all refer to the same products: compressed earth block [4], pressed brick [5–7], pressed block [8],
compressed stabilized earth block – CSEB [9–12], soil cement solid
bricks [13–24], soil–cement block [25], ground blocks cements
⇑ Corresponding author. Tel.: +34 913365767; fax: +34 913363688.
E-mail addresses: jaime.cid@upm.es (J. Cid-Falceto), f.ruiz@upm.es (F.R. Mazarrón), ignacio.canas@upm.es (I. Cañas).
0950-0618/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.conbuildmat.2012.08.019
[26], compressed earth brick [8] or stabilized soil blocks [27]. The
most common format is a rectangular parallelepiped (or prismatic)
formal with a length ‘‘l’’, a width ‘‘w’’ and a height ‘‘h’’, obtained
from static or dynamic compression of wet earth, followed by an
immediate stripping, and that may contain stabilizers or additives
to achieve or develop the particular features of the products [4,26].
In Fig. 1, it compiles the sizes of the CEB accepted in the official
normative of the countries that have a standard of compressed
earth block. However, in the Spanish standard UNE 41410 [4],
NMAC 14.7.4 [28] or the American regulation published by ASTM
International [8], sizes and tolerance of the blocks are not specified,
allowing some liberty in the making of these earth materials.
It can define the CEB as the product obtained by compression of
wet earth, followed by a stripping, and that may contain stabilizers
or additives to achieve certain properties and which dry compressive strength equals or is more than 2 MPa.
Mechanic compression improves the physical properties of
these blocks. Benefits of using earth in this manner include
improved strength and durability as compared with adobe [29].
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J. Cid-Falceto et al. / Construction and Building Materials 37 (2012) 738–745
Fig. 1. Sizes of blocks (length, width, height) in international normative (CEB).
Besides, the advantages of these CEB are that they do not need the
high temperature curing as required by fired clay bricks [30] and
the optimum compression level is reached by hydraulic presses.
1.2. Standards for compressed earth block
The number of normative documents on compressed earth
block (CEB) that were identified and used in this article are forty
four. The totality of international norms in reference to the CEB
are:
The norm IS 1725 [25] from India, twelve norms NBR [13–24]
from Brazil, fourteen norms ARS [31–44] from African Regions,
two norms NT [45,46] from Tunisia, three norms NZS [5–7] from
New Zealand, one norm KS 02-1070 [27] from Kenya, one norm
XP P13-901 [47] from France, one norm NTC 5324 [26] from
Colombia, one norm UNE 41410 [4] from Spain, one norm ASTM
E2392M-10 [8] from the American Society for Testing and Materials, and lastly, one norm NMAC 147.4 [28] from New Mexico. In
addition to these, three normative documents of great international prestige are EBAA 2001 [48], HB 195 [49] and Bulletin 5 [9].
In this normative about compressed earth blocks, the application field in 85% of the analyzed standards and regulations contemplates the stabilization of the blocks. In the rest of the documents it
contemplates blocks with or without stabilizers always that
mechanical specifications referred in the document are accomplished. This is the case of the first European normative [4], which
limits the amount of stabilizers and additives to 15%.
A compressed earth block is considered valid if the proposed
mechanical specifications are complied, needing a minimum value
of compression (dry and wet values). The amount of moisture of
the block influences the values of compression [50], so that a dry
value is obtained when the CEB is tested when the weight is constant after two consecutive loads; or a wet value if the test is performed on the block previously submerged in water. In most of the
international standards, it considers CEB those blocks that have a
compression value in dry that is equal to or more than 2 MPa; case
of the Brazilian standards [13], Colombian standard [26], Indian
standard [25] or the experimental French standard [47].
1.3. Typologies of CEB: standards
The typologies of compressed earth blocks, which are defined in
the standards and regulations, are classified according to different
properties:
Table 1
Drip and spray erosion test, international normative.
Technical
documents
Reference
IS 1725
NZS
SAZS 724
SLS 1382
UNE 41410
ASTM E2395M-10
EBAA 2001
HB 195
Bulletin 5
[25]
[5–7]
[65]
[10–12]
[4]
[8]
[48]
[49]
[9]
Drip erosion
Spray erosion
Technical
X
X
X
X
X
X
b
a,
c
b
b
a,
a,
a,
a,
X
X
X
X
X
X
X
X
(a) Adobe; (b) compressed earth block; (c) rammed earth.
Fig. 2. Minimum values of dry and wet compressive strength in all international standards (CEB).
b, c
b,
b,
b,
b,
c
c
c
c
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J. Cid-Falceto et al. / Construction and Building Materials 37 (2012) 738–745
Table 2
Specifications of spray erosion test, according to International standards.
Technical documents
Sample
Tested face
Number of samples
Exposed area (area £ mm)
Spray time (min)
Observations (min)
Application distance (mm)
Pressure (kPa)
Outlet nozzle (£ mm)
Erosion rate (mm/min)
Evaluation system
Maximum impact velocity (m/s)
Maximun rain rate (mm/h)
Drop diameter (£ mm)
IS 1725
NZS
SLS 1382
ASTM E2395M10
EBAA 2001
HB 195
Bulletin 5
Whole block
Table of
block
3
–
120
–
180
147
100
No
Yes
6.5
15–30
2–4
Whole block
Table of
block
–
150
60
15
470
0–50
153
Yes
Yes
–
–
–
Whole block
Orientation as intended in wall
construction
3
150
60
15
500
50
–
–
Yes
–
–
–
Whole block
Table of block
Whole block
Table of
block
5
70–150
60
15
470
0–50
–
Yes
No
–
–
–
Whole block
Table of
block
5
70–150
60
15
470
0–50
–
Yes
Yes
–
–
–
Whole block
Table of
block
1
150
60
15
470
0–50
–
Yes
Yes
–
–
–
– According to the total volume of holes, two kinds of blocks are
defined: the solid block in which the total apparent volume (Vt)
is more than 85%; and the hollow block, in which the Vt is less
than 85% [26,16].
– According to the aspect or texture: ordinary blocks that will be
coated; face blocks that are to be used without render [4,26].
– Mechanic specifications, complying with the African regulations
[31–44], or from Tunisia [45,46], are classified in three categories: category 1, structural elements which are not load-bearing
and structural elements capable of withstanding limited external loads; category 2, structural elements capable of withstanding important external loads; category 3, structural elements
capable of withstanding high external loads. A summary of minimum values of dry and wet compressive strength needed by
the CEB, are detailed in Fig. 2.
– According to their capillarity specifications: weak capillarity
(index of absorption by capillarity, Cb 6 20); little capillarity
(Cb 6 40) [26,47].
– According to the environment where they are, it divides in three
categories: dry, wet with aggression of the water by lateral
sprinkling or wet with vertical penetration [31,45,46].
2. Durability of earth blocks in normative documents
Durability of the earth materials is one of the main aspects that
must be considered when characterizing a material based on unbaked earth, since its affinity for water is one of the main drawbacks of this material [51]. There are many authors [52–56] that
propose different laboratory tests for the study and analysis of
water erosion on the unbaked earth materials, getting dispersed
results due to the variability of their technical test specifications.
2.1. Standards of durability with erosion test
After studying the normative international panorama [57], all
regulations, standards or normative documents regarding the
durability of the earth systems opposite to the erosion of water
are analyzed. The tests currently used to check the effect of water
on this kind of material are the spray erosion test and the drip erosion test. Table 1 shows normative documents in which any of
these two kinds of existing erosion tests are mentioned. Indicating
the constructive technique to which the proposed test is applied.
These tests have been proposed in numerous documents and are
the object of study of many authors [58–64]. Both are considered
empirical. The ‘‘spray erosion test’’ is referred to by some authors
as a direct replica of the erosion originated by rain water [58]
–
150
60
15
470
0–50
153
Yes
Yes
–
–
–
studying its application on real conditions. The ‘‘drip erosion test’’
is a good cheap test for testing bricks in areas of little rain [63].
2.2. International normative to CEB: specifications to erosion test
Spray erosion test is an empirical test developed by Commonwealth Scientific and Industrial Research Organization (CSIRO).
The drip erosion test was developed by the University of Technology of Swinburne, Australia, which is currently known as Swinburne accelerated erosion test. The drip erosion test is used in
the Spanish standard UNE 41410:2008 [4].
These tests are sometimes applicable to several construction
techniques with earth as it is the case of the New Zealand standard
[6] or to one technique only, as it is the case of Zimbabwe [65]. This
study focuses on the test methods applied internationally to CEB.
All the tests are based on the same ground of subjecting a test tube
to a pressure spray for a certain amount of time or until specimen
is penetrated (spray erosion), or else to a constant water fall for a
certain amount of time (drip erosion), in order to evaluate afterwards the damage caused in both cases.
In the spray erosion test the following parameters are defined:
sample, tested face, number of samples to be tested, exposed area,
spray time, observations, application distance (nozzle-specimen),
pressure, etc., Table 2 contains the explanations of the ‘‘spray erosion test’’ procedures for the compressed earth blocks. For the
cases of the drip erosion test the height of the water fall or the
inclination of the sample to be tested are indicated.
For the interpretation of the evaluation criteria regarding the
validity or invalidity of the sample, the erodibility indexes are
established (Table 3), case of the New Zealand standards [5–7].
Furthermore, the norm NZS 4299 [7], introduces a map with wind
zones limiting the materials according to the erodibility index
(Table 3), for which the criteria of acceptability of all materials is
to have an erodibility index inferior to five or a depth of erosion
inferior to 120 mm (D120mm).
Other standards limit the erosion of the block, to less than
10 mm, like in the standards IS 1725 [25] or SLS 1382 [10]. Differently, in the Australian documents EBAA 2001 [48] and HB 195
[49], the test is proposed and described, but no criteria are offered
for its evaluation.
3. Research objectives
The objective of this research, in addition to that of analyzing
the Spanish products, is to analyze the usefulness of the international tests as a reference in the writing of future standards.
J. Cid-Falceto et al. / Construction and Building Materials 37 (2012) 738–745
741
Fig. 5. CEB type 1 after 30 min in spray erosion test, with two different areas.
These tests help us to better know the applicability of the earth
products and to propose a series of modifications to obtain more
homogeneous results, allowing us to establish levels of quality
and safety of the products, characterize the materials and facilitate
comparative analysis between products.
The present article studies sole three Spanish products in industrial format that have these features.
4. Materials
Three kind of CEB are used that cover the present market in Spain, all of them
solid blocks. These are identified as type 1 (non-stabilized block) and as type 2 and
type 3 (stabilized blocks). The purpose of stabilizing earth-based materials is to improve their resistance to the detrimental effects of water, both blocks are stabilized
with cement at the 6% (block type 2), and cement–quicklime at the 8% (block type
3). Fig. 3 shows the orientation of the compression of each one of the blocks made in
Spain.
The CEB were analyzed to determine its characteristics. A granulometric analysis was developed to determine proportion of different sized particles in the soil,
expressing the quantity as the percentages which passed through the different
sieves according to UNE 103101 [66] and Atterberg Limits and group index of the
soil according to UNE 103103 [67] and UNE 103104 [68] (see Table 4).
For the application of international test, it develops two prototypes that have
great versatility in the system allowing the validation of all the technical specifications proposed in the analyzed normative documents. In the spray erosion test,
pressures, distances of application and/or area of the exposed zone can be changed
(Fig. 4). In the drip erosion test it can change the height of application and/or the
quantity of water.
0.05 MPa of pressure and an area of application of 0.150 m of diameter. It will indicate whether it is suitable (D < 120 mm) or not according to the criteria established
by the New Zealand standard and in the case where the analyzed CEB is suitable,
which erodibility index it corresponds to.
5.1.1.2. Procedure B. This method, complying with standard SLS 1282 [10–12]. It
keeps the same conditions than with procedure A. It modifies the distance of application to 0.500 m. According to the criteria of evaluation of this test procedure, the
perforations performed after the application of the spray erosion test must not be
more than 10 mm deep.
5.1.1.3. Procedure C. This method, complying with standard IS 1725 [25]. It increases
the pressure of application up to 0.15 MPa and the distance of application is reduced to 0.180 m. According to the criteria of evaluation of this procedure, the
CEB must not suffer a weight loss higher than 5%.
5.1.2. Drip erosion test
The test procedure specified in diverse normative documents will be applied,
UNE 41410 [4], HB 195 [49] y EBAA [48].
5.1.2.1. Procedure D. This method, complying with standard UNE 41410 [4]. For
10 min a quantity of 500 ml of water is applied. It tests two samples of each type
of CEB and it applies the criteria of evaluation of the standard, if the hole is equal
or less than 10 mm, the CEB is apt, while if it is more than 10 mm, it will not pass
the criteria of the test.
The test method indicates that the height of the water fall must be 1 m, the time
of test 10 min and the positioning of the sample 27° respect of the horizontal.
5.2. Tested faced in CEB to erosion tests
5. Experimental work: methods
For this part of the present work, two different tests were programmed: the
spray erosion test and the drip erosion test. Initially the testing procedures are applied (procedure A–D) and afterwards it is analyzed whether testing one side or another of the block influences the erosion tests.
5.1. Erosion test: procedures
The different procedures used in this work are: procedure A (spray erosion test
according to standards NZS), procedure B (spray erosion test according to standards
SLS), procedure C (spray erosion test according to standard IS) and procedure D
(drip erosion test according to standard IS).
5.1.1. Spray erosion test
In the case of this test, it will develop the same test on each type of block, with
three different procedures according to the analyzed international regulations. That
is, it will test nine samples in each one of the procedures detailed below.
5.1.1.1. Procedure A. Complying with the standard NZS [5–7] and the Australian normative documents. Duration of the test, 60 min (interruption of the test every
15 min to observe and analyze the sample); a distance of application of 0.470 m;
This section of the investigation consists in analyzing whether the tested face
influences the results of the erosion. Both the spray erosion test and the drip erosion
test will be applied over both sides and faces of each one of the three blocks.
5.2.1. Spray erosion test
Three kinds of CEB will be tested on both sides and faces according to the three
procedures indicated by international norms. For each one of these procedures (A–
C) 12 blocks are tested.
5.2.2. Drip erosion test
Three kinds of CEB are tested on both sides and faces according to the procedure
indicated in the first non-experimental European norm UNE 41410. For the study of
these three types of blocks, twelve blocks have to be tested according to the procedure D.
6. Results and discussion
The first step consists of the analysis of the study of the tested
face and, based on the results, the procedures of testing here described will be applied.
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J. Cid-Falceto et al. / Construction and Building Materials 37 (2012) 738–745
Table 3
Erodibility indexes from spray erosion test, NZS 4298.
Erodibility index
Criteria (mm)
Result
1
2
3
4
5
0 6 D < 20
20 6 D < 50
50 6 D < 90
90 6 D < 120
D P 120
Pass
Pass
Pass
Pass
Fail
6.1. Study of the tested faces
Firstly, the results obtained when applying the ‘‘spray erosion
test’’ to the three kinds of compressed earth blocks are analyzed
(procedures A–C). When applying the three procedures of the test
to the sides and faces of block 1, the first results were negative
(fail), a rupture and a disgregation having been produced in every
case.
Block 1 does not meet any of the criteria of evaluation of the
three procedures at hand. In the case of blocks 2 and 3 a positive
evaluation is obtained (pass) when applying the three testing
procedures.
The application of the specifications of the three testing procedures (procedure A, B, and C), do not produce an erosion on the
side or face of the three blocks that were analyzed. This means that
the position of the block for this test does not influence the final
result, according to the criterias of evaluation proposed by the procedures A–C.
Secondly, a drip erosion test is applied (procedure D). All blocks
(blocks 1–3) meet the requirements of procedure D. In spite of differences in erosion having been found in block 1 when tested on
the side a (erosion 5 mm) or on side b (erosion 9 mm), while that
on their faces the same erosion is obtained on both cases (face a
and face b have a depth of erosion of 4 mm).
Fig. 3. Orientation of the compression, in CEB made in Spain.
Acknowledging this, it is recommended that the drip erosion
test is used for CEB 1 (procedure D) for side a, side b, and for one
of the two faces of each sample. The value of erosion of the block
to be selected will be the highest figure of erosion provided by
any of these. For the rest of the blocks it is recommended to test
in all cases the ‘‘face a’’ of the corresponding block, since no differences between the sets of results have appeared.
6.2. Study of the testing procedures
In each of the three kinds of CEB made in Spain, the four test
procedures described in the previous section were performed,
three of them are specifically of the spray erosion test and the procedure D is the drip erosion test specified in the CEB Spanish standard [4]. The results of the tests performed are shown in Table 5.
6.2.1. Spray erosion test
When applying this test, all CEB stabilized, block type 2 and
block type 3, are apt according to the technical specifications of
the different methods. Instead, block type 1 (unstabilized block),
does not pass the conformity criteria.
Comparing the different test procedures, procedure C is a more
aggressive method than the rest of test procedures (processes A
Fig. 4. Spray erosion test, UPM model.
Table 4
Results of the granulometric analysis, Attemberg limits and size of the CEB.
CEB type 1
CEB type 2
CEB type 3
Percent passing (%)
Atterberg limits
UNE sieve designation
Liquid limit (%)
Plastic limit (%)
Plastic index (%)
a (mm)
b (mm)
c (mm)
20.3
20.2
28.3
14.1
18.5
19.2
6.2
1.7
9.1
306
295
290
166
140
145
103
90
95
10
6.3
5
2
0.5
0.32
0.08
98.6
100
100
98.3
99.6
100
98.3
99.4
100
93.9
86.9
92.4
75.3
48.2
57.1
59.1
31.2
45.5
14.4
11.4
18.8
Size
Table
15
Pass 4 mm
Pass – mm
Pass – mm
Faila
Pass – mm
Pass – mm
Faila
Pass – mm
Pass – mm
743
and B). However, this difference does not affect the results according to their criteria of evaluation.
Furthermore, as for what the area of application is concerned,
many of the studied standards appoint the area in a circular surface of 0.150 m of diameter, but if it analyzes the size of the CEB
currently made all over the world (Fig. 1), in a great number of
them, the area of exposure is bigger than the faces of the tested
CEB. This also happens with the CEB made in Spain. To solve this
problem, it proposes to modify the area of application into a circular area of 125 mm of diameter, an area that covers the face
of the CEB made in Spain (Fig. 5). Different results are obtained
depending on the stabilization of the blocks:
Edge b
14
Pass 9 mm
Pass – mm
Pass – mm
9
8
Edge a
13
Pass 5 mm
Pass – mm
Pass – mm
– For the non-stabilized CEB (type 1), the erosion degree decreases
considerably if a smaller exposed area is used (125 mm of diameter). And the penetration of water is less than when the area of
application does not cover the table of the block, as seen on the
edge of the tested CEB. If the surface affected by the applied
stream of water being applied is adjusted to the tested face of
the block, the erosion produced will be inferior (g < f), see
Fig. 5. In the same way the shaded area shows the advance of
humidity over the block, being inferior if the surface where it
is applied is the same as the face being tested.
– In stabilized CEB, decreasing the area exposed according to the
geometry of the tested CEB does not affect the results obtained.
6.2.2. Drip erosion test
All the analyzed CEB are apt for their use in construction,
according to the trial procedures analyzed at the international level. In the non-stabilized CEB, the media depth of the erosion is
6 mm deep 10 min after it is tested. On the other hand, for the stabilized blocks the erosion depth is practically zero.
The maximum erosion produced on the blocks that were not
stabilized (block 1) is not produced due to the direct fall of the
drop of water but rather by the runoff that takes place, resulting
in a greater loss due to this effect. It is recommendable to use a
criteria of evaluation relating the blocḱs loss of mass, around 5%
of the maximum loss of weight, as has been proposed in other
articles on the subject of international norms of erosion [25].
Table
12
Pass 4 mm
Pass – mm
Pass – mm
Faila
Pass – mm
Pass – mm
Faila
Pass – mm
Pass – mm
Faila
Pass – mm
Pass – mm
Faila
Pass – mm
Pass – mm
7
6
5
Proc. B (deep in mm)
4
Proc. C (deep in mm)
J. Cid-Falceto et al. / Construction and Building Materials 37 (2012) 738–745
Edge b
11
Pass 9 mm
Pass – mm
Pass – mm
Rupture of the block.
Edge a
10
Pass 5 mm
Pass – mm
Pass – mm
This article presents an analysis of the durability properties
when exposed to water of the three kinds of CEB made in Spain to
be used as construction material. It has been tested according to
the test procedures of international standards for construction
materials with earth, specifically for compressed earth blocks. Both
tests (spray and drip erosion tests) have been applied to the products made in Spain, reaching the following conclusions, which can
serve as a base for the normalization of the durability test:
a
Type test
Samples
Block 1
Block 2
Block 3
Faila
Pass I.E 1
Pass I.E 1
Block 1
Block 2
Block 3
Drip test
Faila
Pass I.E 1
Pass I.E 1
Faila
Pass I.E 1
Pass I.E 1
1
Samples
Proc. D (deep in mm)
3
2
Spray test
Proc. A (deep in mm)
Type Test
Table 5
Results of the spray and drip erosion tests in all CEB.
7. Conclusions
– The criteria of evaluation in the spray erosion test are varied making it difficult to carry out the comparison between these two criteria. There is a need to unify the procedures in a single test.
– Spray erosion test is a method applicable to the stabilized CEB
(types 2 and 3), while for non-stabilized blocks (type 1) it is too
aggressive. Those blocks that are not suitable must be rendered
if they are to be used in exterior, or they must be used mainly
for interior faces.
– Performing the spray erosion test with procedures A, B and C
do not show differences in the results for the CEB types 2
and 3 since the content of the stabilizer increases the CEB́s
capacity of resistance to erosion.
– In the case of the CEB analyzed in this study (CEB made in
Spain), it has been proven that the erosion results (spray erosion test) do not vary depending on which face of the object
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J. Cid-Falceto et al. / Construction and Building Materials 37 (2012) 738–745
is tested. However, if a testing method for a ‘‘spray erosion test’’
is developed for a new regulation, it is necessary to indicate
which is the tested face. It is because of this that it is recommendable to initially test one or the other faces or sides of the
object at random, and in the case of obtaining different results,
the value of the erosion should come to be considered that of
the most unfavorable result.
– To decrease the area exposed in the spray erosion test affects
only affects non-stabilized CEB, thus, it is advised to keep the
following ratio:
e<a
where ‘‘a’’ is the width of the CEB and ‘‘e’’ the diameter of the circular area of application (Fig. 5).
– After evaluating the three procedures (A–C) of the spray erosion
test, the procedure B is considered the most recommendable
due to its methodology and the system of evaluation it applies.
– Drip erosion test is a valid method for not-stabilized CEB, whilst
for stabilized Spanish blocks, not quantifiable differences are
found in their results.
– It is concluded that the criteria of evaluation of the ‘‘drip erosion
test’’ should be modified. The criteria of evaluation must be
related to the loss of weight of the CEB (loss of weight >5–
10%) and not to the depth of the erosion produced at that
moment.
Applying these durability tests to the CEB made in Spain, it confirms that all the stabilized CEB tested in this article are apt for
constructions with earth, since they comply with the specifications
of international standards. The use of non-stabilized CEB is valid
for interior faces and exterior walls by rendering them or applying
a similar protection.
Acknowledgements
This study has been carried out as part of the BIA2006-099170
research project ‘‘Development of earth-based material to rural
construction: adobe, compressed earth blocks, rammed earth and
poured earth as sustainable construction systems’’, funded by the
Spanish Ministry of Science and Innovation.
References
[1] Minke G. Manual de construcción en tierra. 1994 ed. Montevideo-Uruguay:
Editorial Nordan-comunidad; 2001.
[2] Reddy BW, Lal R, Rao KSN. Optimum soil grading for the soil–cement blocks. J
Mater Civil Eng 2007;19(2):139–48.
[3] CRATerre-EAG C. Compressed earth blocks: standards. Brussels: CDI; 1998.
[4] AENOR. Compressed earth blocks for walls and partitations. Definitions,
specifications and test methods. UNE 41410. Madrid (Spain): Spanish
Association for Standardisation and Certification; 2008.
[5] SNZ. Engineering design of earth buildings. NZS 4297. Wellington: Standards
New Zealand; 1998.
[6] SNZ. Materials and workmanship for earth buildings. NZS 4298. Wellington:
Standards New Zealand; 1998.
[7] SNZ. Earth buildings not requiring specific design. NZS 4299. Wellington:
Standards New Zealand; 1999.
[8] ASTM. Standard guide for design of earthen wall building systems.
Pennsylvania (United States): ASTM International; 2010. p. 19428–2959.
[9] Middleton G. Bulletin 5. Earth Wall Construction. In: 1992 rbSLM, editor. North
Ryde (Australia): CSIRO Division of Building, Construction and Engineering;
1987.
[10] SLSI. Specification for compressed stabilized earth blocks. Part 1:
Requirements. SLS 1382-1. Sri Lanka: Sri Lanka Standards Institution; 2009.
[11] SLSI. Specification for compressed stabilized earth blocks. Part 2: Test
Methods. SLS 1382-2. Sri Lanka: Sri Lanka Standards Institution; 2009.
[12] SLSI. Specification for compressed stabilized earth blocks. Part 3: Guidelines on
production, design and construction. SLS 1382-3. Sri Lanka: Sri Lanka
Standards Institution; 2009.
[13] ABNT. Tijolo macico de solo-cemento. Especificacao. NBR 8491. Rio de Janeiro:
Associacao brasileira de normas tecnicas; 1986.
[14] ABNT. Tijolo maciço de solo-cimento. Determinacao da resistencia a
compressao e da absorcao d’agua. NBR 8492. Rio de Janeiro: Associação
Brasileira de Normas Técnicas; 1986.
[15] ABNT. Fabricação de tijolo maciço de solo-cimento com a utilização de prensa
manual. NBR10832. Rio de Janeiro (Brasil): Associação Brasileira de Normas
Técnicas; 1989.
[16] ABNT. Solid soil–cement bricks and hollow blocks using hydraulic
brickmaking machine – procedure. NBR 10833. Rio Janeiro (Brasil):
Associação Brasileira de Normas Técnicas; 1989.
[17] ABNT. Solo-cimento – ensaio de compressão simples de corpos-de-prova
cilíndricos. NBR 12025. Rio de Janeiro (Brasil): Associação Brasileira de Normas
Técnicas; 1990.
[18] ABNT. Solo-cimento – ensaio de compactação. NBR 12023. Rio de Janeiro
(Brasil): Associação Brasileira de Normas Técnicas; 1992.
[19] ABNT. Solo-cimento – moldagem e cura de corpos-de-prova cilíndricos. NBR
12024. Rio de Janeiro (Brasil): Associação Brasileira de Normas Técnica; 1992.
[20] ABNT. Bloco vazado de solo-cimento sem função strutural. NBR 10834. Rio de
Janeiro (Brasil): Associação Brasileira de Normas Técnicas; 1994.
[21] ABNT. Bloco vazado de solo-cimento sem função estrutural – forma e
dimensões. NBR 10835. Rio de Janeiro (Brasil): Associação Brasileira de
Normas Técnicas; 1994.
[22] ABNT. Bloco vazado de solo-cimento sem função estrutural – determinação da
resistência à compressão e da absorção de agua. NBR 10836. Rio de Janeiro
(Brasil): Associação Brasileira de Normas Técnicas; 1994.
[23] ABNT. Solo-cimento – ensaio de durabilidade por molhagem e secagem. NBR
13554. Rio de Janeiro (Brasil): Associação Brasileira de Normas Técnicas; 1996.
[24] ABNT. Solo-cimento – determinação da absorção d’água. NBR 13555. Rio de
Janeiro (Brasil): Associação Brasileira de Normas Técnicas; 1996.
[25] BIS. Specification for soil based blocks used in general building construction. IS
1725 Indian Bureau of Indian Standards; 1982.
[26] ICONTEC. Ground blocks cement for walls and divisions. Definitions.
Especifications. Test methods. Conditions of delivery. NTC 53242004.
[27] KEBS. Specifications for stabilized soil blocks. KS02-1070:1993. Nairobi: Kenya
Bureau of Standards; 1999.
[28] CID. New Mexico earthen buildings materials code. NMAC 1474. Santa Fe:
Construction Industries Division; 2009.
[29] Mesbah A MJC, Walker P, Ghavami K. Development of a direct tensile test for
compacted earth blocks reinforced with natural fibers. J Mater Civil Eng
2004;16(1):95–8.
[30] Shon CS, Saylak D, Zollinger DG. Potential use of stockpiled circulating
fluidized bed combustion ashes in manufacturing compressed earth bricks.
Constr Build Mater 2009;23(5):2062–71.
[31] ARSO. Compressed earth blocks, standard for terminology. ARS 670. Nairobi
(Kenya): African Regional Standard; 1996.
[32] ARSO. Compressed earth blocks, definition, classification and designation of
compressed earth blocks. ARS 671. Nairobi (Kenya): African Regional
Standard; 1996.
[33] ARSO. Compressed earth blocks, definition, classification and designation of
earth mortars. ARS 672. Nairobi (Kenya): African Regional Standard; 1996.
[34] ARSO. Compressed earth blocks. Definition, classification and designation of
compressed earth blocks masonry. ARS 673. Nairobi (Kenya): African Regional
Standard; 1996.
[35] ARSO. Compressed earth blocks. Technical specifications for ordinary
compressed earth blocks. ARS 674. Nairobi (Kenya): African Regional
Standard; 1996.
[36] ARSO. Compressed earth blocks – Technical specifications for facing
compressed earth blocks. ARS 675. Nairobi (Kenya): African Regional
Standard; 1996.
[37] ARSO. Compressed earth blocks – technical specifications for ordinary earth
mortars. ARS 676. Nairobi (Kenya); 1996.
[38] ARSO. Compressed earth blocks – technical specifications for facing earth
mortars. ARS 677. Nairobi (Kenya): African Regional Standard 1996.
[39] ARSO. Compressed earth blocks – Technical specifications for ordinary
compressed earth block masonry. ARS 678. Nairobi (Kenya): African
Regional Standard; 1996.
[40] ARSO. Compressed earth blocks – technical specifications for facing
compressed earth block masonry. ARS 679. Nairobi (Kenya): African Regional
Standard; 1996.
[41] ARSO. Compressed earth blocks. Code of practice for the production of
compressed earth blocks. ARS 680. Nairobi (Kenya): African Regional
Standard; 1996.
[42] ARSO. Compressed earth blocks. Code of practice for the preparation of earth
mortars. ARS 681. Nairobi (Kenya): African Regional Standard; 1996.
[43] ARSO. Compressed earth blocks. Code of practice for the assembly of
compressed earth block masonry. ARS 682. Nairobi (Kenya): African
Regional Standard; 1996.
[44] ARSO. Compressed earth blocks. Standard for classification of material
identification tests and mechanical tests. ARS 683. Nairobi (Kenya): African
Regional Standard; 1996.
[45] INNORPI. Blocs de terre comprimée ordinaires – spécifications techniques. NT
2133: Tunisian Standards; 1996.
[46] INNORPI. Blocs de terre comprimée – définition, classification et désignation.
NT 2135: Tunisian Standards; 1996.
[47] AFNOR. Compressed earth blocks for walls and partitions: definitions –
specifications – test methods – delivery acceptance conditions. XP P13-901.
Saint-Denis La Plaine Cedex: Association française de Normalisation; 2001.
J. Cid-Falceto et al. / Construction and Building Materials 37 (2012) 738–745
[48] EBAA. Earth building book. In: Australia EBAA, editor. Draft for comment.
Wangaratta (Australia); 2001.
[49] Australia S. The Australian earth building handbook. HB 195. Sydney
(Australia): Standards Australia; 2002.
[50] Walker P, Morel JC, Pkla A. Compressive strength testing of compressed earth
blocks. Constr Build Mater 2007;21(2):303–9.
[51] GalanMarin C RG-C, Petric J. Clay-based composite stabilized with natural
polymer and fibre. Constr Build Mater 2010;24(8):1462–8.
[52] Ogunye FOBH. Development of a rainfall test rig as an aid in soil block
weathering assessment. Constr Build Mater 2002;16(3):173–80.
[53] Mbumbia LWAM, Tirlocq J. Performance characteristics of lateritic soil bricks
fired at low temperatures: a case study of Cameroon. Constr Build Mater
2000;14(3):121–31.
[54] Hall MR. Assessing the environmental performance of stabilised rammed earth
walls using a climatic simulation chamber. Build Environ 2007;42(1):139–45.
[55] Ola SA. Durability of soil–cement for building purposes. Rain erosion
resistance test. Constr Build Mater 1990;4(4):182–7.
[56] Venkatarama BVJKS. Spray erosion studies on pressed soil blocks. Build
Environ 1987;22(2):135–40.
[57] Cid J, Mazarron FR, Canas I. The earth building normative documents in the
world. Inf Constr. 2011;63(523):159–69.
[58] Walker PJ. Strength and erosion characteristics of earth blocks and earth block
masonry. J Mater Civil Eng 2004;16(5):497–506.
[59] Heathcote KA, Ravindrarajah RS. Relationship between spray erosion test and
the performance of test specimens in the field. In: Proceedings of the
[60]
[61]
[62]
[63]
[64]
[65]
[66]
[67]
[68]
745
international conference on sustainable construction into the next
milenium: environmentally friendly and innovative cement-based materials.
Brazil, Sydney: University of Technology; 2006. p. 327–6.
Heathcote KA. An investigation into the erodibility of earth wall units. PhD
Thesis, Sydney (Australia): University of Technology Sydney; 2002.
Guettala AAA, Houari H. Durability study of stabilized earth concrete under
both laboratory and climatic conditions exposure. Constr Build Mater
2006;20:119–27.
Weisz AMK, Nataatmadju A. Durability of mudbrick. Comparison of three test
methods. In: Proceedings of the 4th Australasian masonry conference, Sydney;
1995. p. 249–58.
Heathcote KA. Durability of earthwall buildings. Constr Build Mater
1995;9(3):185–9.
Obonyo EEJ, Baskaran M. Durability of compressed earth bricks: assessing
erosion resistance using the modified spray testing. Sustainability
2010:3639–49.
SAZ. Standard code of practice for rammed earth structures. SAZS 724. Harare
(Zimbabwe): Standards Association of Zimbabwe; 2001.
AENOR. Particle size analysis of a soil by screening. UNE 103101. Madrid
(Spain): Spanish Association for Standardisation and Certification; 1995.
AENOR. Determination of the liquid limit of a soil by the Casagrande apparatus
method. UNE 103103. Madrid (Spain): Spanish Association for Standardisation
and Certification; 1994.
AENOR. Test for plastic limit of a soil. UNE 103104. Madrid (Spain): Spanish
Association for Standardisation and Certification; 1993.