Decorative Concrete Information – Bricks and Blocks

Introduction

There are numerous factors to be taken into account when making quality concrete bricks and blocks. The type of aggregate and cement as well as how the bricks and blocks are cured will have an influence on quality.

A good aggregate is free from chemicals, clay and organic material. A good aggregate will bond well with the cement paste and not react with it.

The denser the finished brick or block is, the stronger it will be. To achieve a dense block with an aggregate that can be vibrated and compacted down easily you need to have an aggregate with evenly graded particles ranging from fine dust up to larger stone of around 9mm. Blending different aggregates often produces the best results.

There are a number of types of aggregates that can be used for brick and block making. These need to be blended to suit the quality of the final product.

NEVER use aggregate that has clay, organic matter or excessive salts in it.

Sand

We supply many types of sand. Some types are more suitable than others for use in brick and block making. Other sand may need to be blended with other aggregates to get the correct consistency and suitability.

Coarse River Sand

This sand is suitable for brick and block making. It should have particle sizes ranging evenly in proportion from fine dust up to 5mm in size.

Coarse Sand

A sand suitably good for brick and block making. As it tends to be more cohesive than other sands, it means that the brick/block compacts down well and the freshly made product does not fall apart easily. Sand is also evenly graded from dust to larger particles. Always check that the sand does not contain clay. Particle sizes should all be smaller than 5mm.

Natural Mined Sand

This sand is mined from quarries and occurs naturally. Slightly coarse evenly graded natural sand is the best for use with bricks and blocks. Natural sand is usually cohesive and makes a strong fresh product.

Stone

Stone ranging from 5mm to 9mm can be used to blend in with finer aggregates. Stone used on its own will not work. Adding stone will often add strength to your cured product but could make the surface of bricks and blocks more rough and porous.

Ash and Slag

Ash and slag by-products from power stations, metal works and other industries are often used in block production.

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