(b) State in sequence, five stages involved in the manual method of manufacturing a sandcrete block after the materials have been batched.
Most candidates were able to state:
- the functional requirements of a concrete foundation;
- in sequence, the stages involved in the manual method of manufacturing a sandcrete block after the materials have been batched.
However, some were unable to sketch the pictorial view of a stepped
foundation correctly.
The expected response to question 4 is as given below:
(a) (i) Functional requirements of a foundation
These include:
- level base to support the element to be placed on it.
- adequate strength to support the building and safely transmit its loads to the subsoil.
- ability to withstand slight ground movement.
- resistance to sulphate or other chemical attacks in the subsoil.
- the property of not being affected by the presence of ground water.
(b) Manufacture of sandcrete blocks
(i) Mix the materials dry by turning them together until the cement is well
blended with the sand and spread out.
(ii) Add the required amount of water and remix to a uniform consistency.
(iii) Fill the mould with the mix and tamp to achieve a dense mass.
(iv) Extrude the moulded block onto a prepared surface and protect against damage.
- Cure the blocks and stack for use.
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