Introduction to concrete building products
Practical Action
very small scale operation. Somewhat larger operations with a number of different types of products
can require operating areas several times this. If space is restricted consider putting up sturdy
shelving to store finished products. This can also help to display the products to the customers.
Cement needs to be stored in a dry storage shed as any exposure to water will cause it to start to
set and harden. More limited protection to wetting of the cement can be provided if the cement
bags are stored under a simple open roofed structure with the bags wrapped securely in plastic or
tarpaulin sheeting.
The sand also needs to be protected from heavy or prolonged rain. This is because most types of
sand readily absorb water and bulk up and increase in weight when they are wetted. It can then
become difficult to add sand in the right proportions to the mix, thus affecting the properties of the
concrete from which it is made. If rain is expected it is best to cover the sand securely with plastic
or tarpaulin sheeting.
Normal working clothes are recommended for the people working at the production site. These
clothes are bound to get covered in concrete. In addition, because of the risk of dropping heavy
moulds or concrete products when carrying them, stout shoes are recommended. Concrete is not
normally harmful to skin, but care should be taken that none get into the eyes. If this happens, the
affected eye should be washed out with plenty of clean water. Hands should always be washed
thoroughly after working with concrete before eating or drinking.
~8 m
~10 m
~6 m
Figure 4: Layout of Small Concrete Products Workshop and Yard Utilising Vibrating Table (page 6).
Illustration from Vibrated Concrete Products Production Manual (Draft), by Amon Ng’ang’a, Building Materials and Shelter
Programme of IT Kenya, October 1994.
Quality Control and Testing
The Importance of Quality Control
Good quality control is very important, even at a small yard, to minimise the use of cement, which
is an expensive commodity, and to ensure that most of the production run is usable. In addition, a
good quality consistent product is likely to be a major factor in ensuring the long-term survival of
the yard and customers will be very much attracted to buying the products.
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