A concrete block is an artificial building unit made from cement, sand, aggregate and water. Unlike fired clay bricks, concrete blocks are not kiln-heated but harden through the hydration process of cement. They are widely used in construction because of their low cost, uniform dimensions and good compressive strength.
Properties
- Compressive strength — available in various strength classes, from lightweight to structural grade
- Dimensional accuracy — factory production ensures highly consistent dimensions
- Moisture sensitivity — concrete blocks absorb more moisture than fired bricks and are therefore more susceptible to frost damage
- Colour — standard grey, but other colours are available through the addition of pigments
Application
- Internal walls — non-loadbearing partition walls
- External walls — as the inner leaf of a cavity wall (with a facing material on the outside)
- Garden walls and boundary walls — combined with concrete coping stones
- Foundation masonry — below ground level, provided the blocks are frost-resistant
Difference from calcium silicate brick
Concrete blocks are sometimes confused with calcium silicate (sand-lime) bricks. The difference lies in the binder: concrete blocks use Portland cement, while calcium silicate bricks use lime that is hardened under steam and pressure (autoclaving).
Related terms
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