Reinforced Concrete Slabs

In Rural Building we do not deal with the construction of flat roofs, even though these would be more appropriate to the local customs. The reason is because the materials to construct a safe, strong flat roof are expensive, and the construction of a reinforced concrete roof is very difficult and complicated.

Therefore, in this course we only treat the construction of relatively small reinforced concrete slabs such as manhole covers, latrine slabs, septic tanks, etc.

CONSTRUCTION

Reinforcement mats are a simple way of reinforcing slabs but they are sometimes hard to obtain and they are expensive. The Rural Builder usually has to rely on single reinforcement bars to reinforce slabs.

Fig. 1 shows a typical arrangement for a circular slab, and Fig. 2 shows that for a rectangular slab.

The distance between the 12 mm main bars is never more than 10 cm. The thickness of the slab can vary between 7, 5 cm for smaller slabs like manhole covers, and up tc 15 cm for covers of septic tanks, or slabs on which people may walk.

- NOTE: This book is not meant to train engineers; it merely gives basic information. If you need to construct a larger reinforced concrete member, you are advised to seek help from a building expert.