This grey powder, when mixed with water, forms the glue to bind together the other ingredients.The most commonly used cement is Normal Portland Cement.
It is so called because of the similarity in appearance of the earliest concrete to Portland Stone- a widely used natural stone of the period of its invention.
The coarse aggregate or stone content provides much of the bulk of concrete. It is important to use a strong, well-graded aggregate. The aim is to combine the different sizes of aggregate in such a way as to achieve the optimum packing of the particles and so reduce voids to a minimum. Aggregates are most commonly crushed rock or naturally occurring gravel.
- Read about Aggregates in the Construction Industry in Ireland here.
FINE AGGREGATE (SAND)
Sand acts as a fill material, filling the voids between the larger particles. It can be either natural sand or crushed rock fines. In general, the finer the sand, the greater the water demand in the concrete mix.
Water is essential to react with the cement, hardening to form a solid matrix, binding the aggregate and sand together.
The water content should not be too high, as the strength will decrease. The general rule is if it’s good enough to drink, it’s good enough for concrete.
These are materials, mainly liquids that are added to the mix to enhance concrete properties.
- Examples of common admixtures and their uses can be found here
- For admixture data sheets, visit the site of one of our corporate members