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European Journal of Applied Sciences – Vol. 12, No. 6
Publication Date: December 25, 2024
DOI:10.14738/aivp.126.18094.
Akeke, G. A., Ewa, D. E., Takim, S. A., & Enang, A. E. (2024). Enhancing Access to Affordable Housing Through the Improved
Mechanical and Durability Properties of Mud-Crete Blocks. European Journal of Applied Sciences, Vol - 12(6). 811-823.
Services for Science and Education – United Kingdom
Enhancing Access to Affordable Housing Through the Improved
Mechanical and Durability Properties of Mud-Crete Blocks
G. A. Akeke
Department of Civil Engineering, University of Cross River,
Calabar, Nigeria and Department of Civil Engineering,
Gregory University Uturu, Nigeria.
D. E. Ewa
Department of Civil Engineering,
University of Cross River, Calabar, Nigeria
S. A. Takim
Department of Mechanical Engineering,
University of Cross River, Calabar, Nigeria
A. E. Enang
Department of Civil Engineering,
University of Cross River, Calabar, Nigeria
ABSTRACT
The results of an experimental study using cement, rice husk ash (RHA), sand, and
laterite as constituents to create solid mud-Crete blocks' mechanical and durability
characteristics are presented in this work. RHA and laterite partially replaced
cement and sand respectively in percentages of 10, 20 and 30%. Grade 32.5
Portland Limestone Superset cement was used and the experimental procedure
carried out on the blocks included compressive strength, water absorption and fire
resistance tests. Curing was by sprinkling and the results showed that at 7 days
curing time the average compressive strengths recorded were 2.97N/mm2 for the
control mix, and 2.65N/mm2, 1.72N/mm2 and 1.09N/mm2 for 10, 20 and 30%
replacements, and after 28 days curing 3.01N/mm2, 2.92 N/mm2 1.93N/mm2 and
1.31N/mm2. 7.12%, 8.10%, 8.52% and 8.78% were recorded as average values for
water absorption after 28 days of curing for the control mix and the replacements
at 10, 20 and 30% respectively. The fire resistance test showed that the specimen
had integrity for 8hrs, 6hrs 18mins, 5hrs 6mins and 3hrs 19mins approximately for
the control batch, 10%, 20% and 30% replacements respectively.
Keywords: mud-Crete, block, Strength, durability, shelter.
INTRODUCTION
Access to affordable and sustainable housing remains a significant challenge globally,
particularly in low-income and developing regions. The housing shortage is exacerbated by the
high cost of traditional building materials like burned bricks and concrete. As a sustainable
alternative, mud-Crete (a combination of stabilized mud and cement) has gained attention for
its potential to provide cost-effective and durable shelter solutions. This literature review
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explores advancements in the mechanical and durability properties of mud-Crete blocks and
their implications for enhancing accessibility to affordable housing. To overcome this
limitation, housing must be made accessible and inexpensive for the general public. Nigeria's
successive administrations have paid special attention to the lack of cheap housing and its high
cost, and they have created a variety of initiatives to increase housing accessibility for the
general people. In an attempt to address the housing crisis, the Nigerian government started
constructing affordable homes for laborers and low-income workers, as well as setting up
industries to generate locally produced building materials. Many nations throughout the world
have stressed the need for locally produced building materials, and there is a disparity between
the price of traditional building materials and their depletion. [1]. He claimed that by keeping
an eye out for inexpensive substitute building supplies, this predicament may be resolved.
Nigeria's past and present administrations have developed a number of programs to address
the housing issues that the nation's residents confront, but none of them have yet to produce
fruitful, tangible outcomes. There is no benefit, stating that the rising cost of housing makes it
unaffordable for those with low incomes. This is hardly surprising given how quickly building
materials like cement, roofing sheets, sanitary fixtures, planks, blocks, etc. are becoming more
and more expensive every day. The soaring cost of cement significantly influences the expense
of producing building blocks. These blocks, being essential structural elements of a building,
represent a substantial portion of the overall construction budget. According to [2], the primary
challenge facing the construction sector in developing countries is the high cost of building
materials, many of which rely on imports. Despite this, housing designs aimed at low-income
groups often overlook their financial constraints, as these designs are frequently tailored to
appeal to wealthier individuals, leaving the economically disadvantaged excluded.
Consequently, low-income earners and peasants are seeking more affordable alternatives for
obtaining construction materials within their budget. One such method, according to landlords
and property developers surveyed in Ogun State's Idiroko area, is to employ 100mm and
125mm strong sand Crete blocks for manufacture.
According to [3], sand Crete blocks are formed or molded using sand, water, and binder- containing cements and defined Sand Crete blocks as comprising of sand, water and binder, an
Evaluation of the Solid Sand Crete Blocks' Compressive Strength -The costliest component in
the creation of sand-Crete blocks in the Idiroko Area of Nigeria is cement, which is used as a
binder. They also confirmed that in order to make their products profitable and accessible to
the general public, manufacturers of Sand Crete blocks use less Ordinary Portland Cement
(OPC) in their production. They believe that in order to reduce the cost of construction, the
general public has come to tolerate these subpar blocks because to the high rate of poverty in
West African nations, especially Nigeria. Blocks made of sand Crete have long been used in
various countries, including Nigeria [4]. A mixture of sand, cement, and water is used to make
Hollow Sand Crete blocks, which are widely used across the world, particularly in Africa. Sand
Crete blocks are one of the main expenses of the most typical buildings in various parts of
Nigeria [5]. Because of its naturally low compressive strength, it is vulnerable to seismic action.
[6] claims that previous studies by other researchers have shown disappointing production
results of commercial sand Crete blocks, with compressive strength significantly lower than
specified strength for building. Blocks made of Sand Crete can be categorized as solid, hollow,
or cellular. These days, sand Crete skin panels and blocks are utilized to improve a building's
appearance as well as to limit wind and moisture intrusion [7]. Sand Crete block is defined by
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Akeke, G. A., Ewa, D. E., Takim, S. A., & Enang, A. E. (2024). Enhancing Access to Affordable Housing Through the Improved Mechanical and Durability
Properties of Mud-Crete Blocks. European Journal of Applied Sciences, Vol - 12(6). 811-823.
URL: http://dx.doi.org/10.14738/aivp.126.18094
the Nigerian Business Preferred as a composite material molded into various sizes using
cement, sand, and water. Sand Crete blocks are construction materials that are generally made
of ordinary Portland cement, water from streams or boreholes, and sharp sand that has been
collected from rivers or streams. The ingredients are combined in the right amounts and
molded into the required shapes and sizes [8]. The most typical sizes of Sand Crete blocks are
450mm × 225mm × 225mm and 450mm × 150mm × 225mm. The blocks can be hollow or solid
[9]. According to [9], the NIS specifically recognizes two types of blocks: load-bearing type A
blocks and non-load-bearing type B blocks. They can both be hollow or solid. Comparing Sand
Crete bricks to other materials reveals how inexpensive they are. They offer exceptional
resistance to harm without requiring the additional cost of protective devices. They no longer
use any environmentally hazardous fabric in their products. Sand Crete blocks don't rust,
degrade, or harbor undesirable insects like other building materials can. Sand Crete blocks are
widely accepted in many construction structures due to their usefulness and adaptability to
various climatic conditions. This is especially true in nations with tropical rainforests that
experience high temperatures and precipitation [10]. Again, in the works of [11], varieties of
sand Crete blocks are distinctive by NIS, type A (load bearing blocks), and Type B (non-load
bearing blocks), and that there are 4 fundamental households of blocks; are solid blocks, hole
blocks, perforated blocks, interlocking blocks. About ninety% of buildings constructed in West
Africa are constructed with sand Crete blocks, making them important constructing material
[12]. After curing, sand Crete block has a relative high compressive strength; variety of
minimum power laid out in NIS 87:2007 is among 2.5N/mm2 to 3.45N/mm2, which
accelerated with increase in density [13] Sand Crete blocks are produced in lots of parts of
Nigeria without reference to any global or countrywide specs, sand Crete blocks are
enormously cheap when in comparison to different construction materials. In addition, they've
higher resistance to rusting, insect and pest assault, crumbling, and are nonhazardous whilst as
compared with different constructing substances [14]
The frequent collapses of buildings in Nigeria, along with the resulting deaths and destruction
of homes, have become a great concern. A subpar and outmoded building material, notably sand
Crete blocks, was one of the many explanations given for these disasters [15] One very
important feature of blocks is their compressive electricity, which is a measurement of how
resistant they are to load software when they are in the crushing mechanism. The quality,
grading, and density of fine aggregates/sand, curing conditions, satisfactory manage, vibration
time, amount of water used, cement-sand blend ratios, hollow space extent, center-web to stop- web ratio, and the type and grade of cement are found to affect the energy of hollow sand Crete
blocks [16]. According to [17], the compressive electricity is defined as the average
compressive energy of five blocks and, for machine-vibrated blocks, cannot be less than
3.45N/mm2 for load-bearing walls and 0.5N/mm2 for non-load-bearing walls. For hand- compacted blocks, it cannot be less than 2.45N/mm2 for load-bearing partitions and 1.8
N/mm2 for non-load-bearing walls.
Blocks are defined by [18] as Mansory units of big length in all dimensions, except for bricks,
but no dimension may be greater than 650 mm, nor may the height exceed the length or six
times the thickness of the block. The sizes of the sand Crete blocks vary: they are 225 mm, 150
mm, 125 mm, and 10 mm, in that order. In Nigeria, sand Crete blocks are used in the
construction of almost 90% of the country's physical infrastructure [19]. For institutional and
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commercial properties, they are highly sought-after as an affordable and durable remodeling
option [20]. In many parts of the United States of America (Nigeria), sand Crete blocks are
produced without regard to neighborhood construction codes or correct shape and satisfactory
work. It has been established that throughout the past ten years, the inclusion of mineral
admixtures in manufacturing materials has significantly improved their workability, strength,
and durability [21]. In an attempt to enhance the aesthetics of the production process and
superior materials in 2000, the Old Business Enterprise of Nigeria (SON) presented a guideline
that outlined the basic requirements and utilized several designs of sand Crete blocks [22]. The
records were evaluated in 2004, and as a result, NIS 87:2004 - general for sand Crete blocks
became the industry standard for sand Crete in the United States. Following additional
examination, NIS 87:2007 recommended for sand Crete block became the accepted reference
report for sand Crete block production in Nigeria. Sand Crete blocks come in two popular sizes:
450mm × 225mm × 225mm and 450mm × 150mm × 225mm. They can be hollow or stable
rectangular shapes. The degree of acceptable control used has an impact on compressive
strength. According to [23], among other factors, the compressive strength of sand Crete blocks
can be affected by a great selection of materials and an appropriate curing procedure.
According to [24], if sufficient energy is required, blocks must be allowed to grow for at least
28 days (by means of curing them) before they are laid demonstrating advancements in
material selection and curing techniques as a means of improving the extraordinary
performance of sand Crete blocks.
One major problem with producing sand Crete hollow blocks is that their tested compressive
electricity did not match the required standards, even when they were made with the help of
the largest commercial block building enterprises [25]. The majority of the blocks made by
commercial block-making companies in Nigeria had 28-day dry strengths ranging from 0.50 to
1.05 N/mm2, according to research on the evaluation of block quality. The cost-effective
production of inferior sand Crete hole blocks was justified by a number of factors. Inadequate
curing, poor craftsmanship, and a negative cement to sand mix ratio had been the main causes
[26]. Thus, the goal of this study is to perform well-conducted experimental investigations into
the mechanical houses of mud Crete blocks made from readily available domestic materials in
order to reduce building costs.
Affordable Housing and Sustainable Building Materials
The demand for low-cost and sustainable building materials is increasing, driven by rapid
urbanization and population growth [27]. Conventional construction materials like cement,
steel, and fired bricks are resource-intensive and contribute significantly to environmental
degradation [28. The adoption of alternative materials such as mud-Crete, which utilizes locally
available soil stabilized with minimal cement, offers a promising solution to this problem [29].
Mud-Crete blocks can be produced using simple and low-energy techniques, making them ideal
for rural and peri-urban areas where infrastructure and resources are limited [30]. Their
affordability and sustainability are critical to addressing the housing deficit in economically
disadvantaged regions.
Durability Properties of Mud-Crete Blocks
The long-term durability of mud-Crete blocks is critical for their adoption in affordable housing
projects. Durability is affected by moisture content, exposure to weathering, and resistance to
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Akeke, G. A., Ewa, D. E., Takim, S. A., & Enang, A. E. (2024). Enhancing Access to Affordable Housing Through the Improved Mechanical and Durability
Properties of Mud-Crete Blocks. European Journal of Applied Sciences, Vol - 12(6). 811-823.
URL: http://dx.doi.org/10.14738/aivp.126.18094
erosion. Cement stabilization significantly improves water resistance and durability, as shown
in studies by [31]. Mud-Crete blocks stabilized with cement exhibit lower water absorption
rates, reducing their vulnerability to weathering and erosion. Moreover, proper curing
methods, such as water curing and controlled drying, enhance the durability of the blocks [32].
Recent studies have explored the use of additives such as fly ash, rice husk ash, and waste
plastic fibers to improve durability. For instance, [33] showed that the inclusion of fly ash
reduces water permeability and enhances the durability of soil blocks.
Environmental and Economic Implications
One of the primary advantages of mud-Crete blocks is their minimal environmental impact
compared to conventional building materials. The production of stabilized soil blocks requires
lower energy inputs and generates fewer carbon emissions [24] Additionally, the use of local
soil reduces transportation costs, further enhancing affordability [25]. Economic assessments
have shown that mud-Crete blocks are 30-50% cheaper than conventional fired bricks or
concrete blocks, depending on the availability of raw materials [26] This cost-effectiveness
makes them a viable solution for affordable housing projects in developing economies.
Challenges and Future Directions
Despite their benefits, mud-Crete blocks face challenges related to standardization, acceptance,
and quality control. Variability in soil properties and the need for skilled labor in stabilization
processes can hinder large-scale adoption [27]. Further research is needed to develop
standardized guidelines for soil selection, stabilization, and testing.
Advancements in material science, such as the use of nanotechnology and bio-stabilizers, offer
new opportunities for improving the mechanical and durability properties of mud-Crete blocks.
Future studies should focus on optimizing stabilizer content, reducing production costs, and
improving the long-term performance of these blocks.
MATERIALS AND METHODS
Materials
Cement:
The cement type used was the Dangote Superset of grade 32.5
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Laterite:
The laterite was gotten from Cross River State Nigeria, with its characteristic red pigmentation.
RHA:
Rice Husk Ash from Obubra Local Government Area of Cross River State, Nigeria, was used for
the research work.
Fine Aggregate:
Sand was gotten from the Adiabo beach of the Calabar river, Cross River State, Nigeria.
It was sharp, clean and without dirt and other deleterious materials.
Water:
The water used for the research was free from salt and other deleterious materials
Mold:
Size of mould used was 112.5mm width x 225mm height x 450mm length.
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Akeke, G. A., Ewa, D. E., Takim, S. A., & Enang, A. E. (2024). Enhancing Access to Affordable Housing Through the Improved Mechanical and Durability
Properties of Mud-Crete Blocks. European Journal of Applied Sciences, Vol - 12(6). 811-823.
URL: http://dx.doi.org/10.14738/aivp.126.18094
Methods
Using a calibrated container, the quantities were measured in volume according to the
predetermined percentages.
First a control mix was done with 100% of cement and sand and no injection of laterite or RHA.
Subsequently, there was replacement of cement and sand with RHA and laterite respectively to
10, 20, and 30%. Mix ratio and water cement ratio adopted were 1:6 and 0.45 respectively.
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Laboratory Tests
Both the blocks and the aggregates were subjected to tests. Among the tests carried out are:
Classification:
This was carried out on the block's laterite and sand components. Before the real check was
performed, the samples were let out to dry in the sun for a whole day. 200g of the samples were
weighed, then loaded into the sieve apertures and subjected to a 5-minute intense vibration
period. The proportion of the samples that passed through the sieve sets was calculated by
measuring and recording the mass of the samples that were retained in each sieve.
Sand Crete Blocks Test:
Compressive Test:
The blocks obtained from the mixes were labelled and weighed in their dry states and recorded.
The compressive tests on the blocks were carried out for early strength at 7 days and also at 28
days of curing. The block's dimensions match the measured and documented inside
measurements of the Mold. The sand Crete block's compressive strength was measured using
a motorized Concrete Compression Testing Machine in compliance with NIS-87, 2004. The
experiments were run after seven and twenty-eight days of melding. Each block was attached
to the machine's compression cell and steadily compressed during the testing procedure until
failure happened.