This research work means to determine
the different properties of sandcrete blocks moulded with a locally excavated
sand, in terms of compressive strength, durability and cost and economic
importance, and that of River Sand. And
after, compare the two strengths of the sandcrete which will help in
recommending the right give the desired strength for the designed strength for
a particular purpose.
as case study, Nsude is in Udi, Enugu west, Enugu State.
1.1 BACKGROUND OF THE STUDY
Sandcrete is a yellow-white building
material made from a binder (Portland cement), sand in a ratio of circa 1:8,
and water. Sometime other ingredients may be added to reduce the amount of
Portland cement such as “pozzolanas and rice husk ash”. Sandcrete is similar
but weaker than mortan for which the ratio is 1:5.
Sandcrete is usually used as hollow
rectangular blocks similar to concrete masonry units, often 45cm (18”) wide,
15cm (5.9”) thick and 30cm (12”) with hollows that run from top to bottom and
occupy around one third of the volume of the block.
1.2 STRENGTH AND USAGE
final compressive strength of sandcrete can be as high as 4.6N/mm2
which is much less than concrete’s 40N/mm2. Sandcrete is unsuitable
for load-bearing columns, and is mainly used for
of a house
tank and soak away tank’s
a generator’s house.
In Nigeria, measured strength of
commercial available sandcrete blocks was found to be between 0.5 and 1N/mm2,
which is well below the 3.5N/mm2 that is legally required. This
development may be due to the need of the manufacturers to keep the price low,
and since the main cost-factor is the Portland cement, they reduce that, which
results in a block that starts behaving more like loose sand.
1.3 SANDCRETE BLOCK SIZES
They are many different types of
blocks used in modern building, they include:
9” hollow blocks (450mmx225mmx225mm)
hollow blocks (450mmx150mmx225mm)
solid blocks (450mmx150mmx225mm)
solid blocks (450mmx125mmx225mm)
solid blocks (450mmx225mmx225mm)
1.4 CONSTITUENT MATERIALS OF
These include cement, fine aggregate
(sharp sand) and water.
This refers to any adhesive and the
material used in connection with block and it is referred to as “hydraulic
cement” because the setting and hardening depends on the preserve of water. The
cement widely used in civil work is called “Ordinary Portland Cement”.
1.4.2 FINE AGGREGATE
The two major types of sand used are
white and coloured sand. The sand were not free from materials such as dust,
silt, tree roots etc. The sources of sand include pits, rivers and sea.
type of water available can be used to mould sandcrete blocks. This includes
water from stream, rivers, boreholes etc.
1.5 STATEMENT OF THE PROBLEM
Apart from bad mixing ratios, which
happen even some sandcrete blocksproducers add more yield of blocks, some other
things can cause blocks to be in bad condition which can affect the quality of
the sandcrete produced.
USING OF BAD CEMENT
Due to the
prevailingadverse economic conditions, some sandcrete block makers tend to go
for very cheap cement which may not have the required quality to bind a solid
block. These block break soon after they are made. Some cement sellers who had
cement keptin stock for so long sell it at give away price to the sandcrete
block makers if the notice that the quality of the cement has detoriated.
1.5.2 RE-BAG CEMENT
Another thing to note with cement is
that some cement sellers re-bag cement, removing some quantity of cement or put low quality cement
product in a bag of a high quality and trust cement brand. Theration you thought
you are using to produce a given quality has been compromised and it will
produce a low quality block that can easily break even before it is being used
for the project.
1.6 THE OBJECTIVE OF THE STUDY
This project research will help us to understand the
different strength of sandcrete blocks produced with locally excavated sand and
This will also help to know the properties of Nsude
sand after laboratory test has been carried out.
This will help us in determining the moulding methods
and properties of sandcrete blocks. These properties are determined by the
ratio of block constituents such as cement, water and sand.
1.7 SCOPE OF THE STUDY
of this project work is limited to obtaining the comparison of locally
excavated sand with River sand in terms of strength in sandcrete blocks.(Nsude
as case study).
1.8 SIGNIFICANCE OF THE STUDY
1. To help us
understand the strength of sandcrete blocks produced with locally excavated
sand and River sand in Nsude.
2. To help us
determine the properties of Nsude sand after carrying out laboratory test.