Topic Menu

Cyber-chess a chess instruction site

Questions on Expansion and Contraction

Q4. When laying concrete slabs (or brick pavers) in a patio a gap it left between them. This gap is filled with a soft substance such as sand.

Why is this done?

When the weather gets warmer the slabs will expand. If they had been tightly fitted the expansion would put a strain on them and they would crack or buckle. The sand would allow them to expand, as it is easily compressed.

When the weather gets colder the slabs would contract. This would result in larger gaps between them, but as the gaps have sand in them they would be less of a trip hazard than if they had no filling at all.

Always state what happens in hotter and colder conditions if the temperature change is not indicated.

(5 marks)