Concrete Mix Design

Is all concrete created equal? Hardly! And neither should it be. A major factor in the success or failure of a concrete project is the product mix design. As techniques and technology evolve, there is an ever increasing pool of options when it comes to creating the perfect mix, but there are a few key factors that will dictate the design.

What are these factors?

1.Compressive strength – the amount of pressure the cured concrete can withstand (measured in MPa)

2.Durability – length of time the concrete will last without significant deterioration

3.Workability – ability of concrete in the plastic (fresh, uncured) state to fill the form/mold properly

4.Cost

What ingredients go into the creation of a design mix?

1.Cement – powdered, processed combination of calcium, silicon, aluminum, iron and small amounts of other ingredients, combined with water to make the paste responsible for setting, hardening and strength development of concrete

2.Aggregate – sand, gravel, crushed rock, suspended particles in the concrete mix

3.Water

4.Chemical/mineral admixtures – accelerators, retarders, plasticizers, etc., added to concrete mix to provide desired properties

The proportions of these ingredients are determined by specific performance requirements in both the plastic state and the hardened state.

It is important that the concrete will be strong enough and durable enough to hold up under environmental and functional stress while remaining workable during the pouring and placing process. It would do no good to have concrete that is strong and durable, but impossible to place because it can’t contour to the required forms. Inversely, what good is concrete that is easily placed but can’t stand up to the elements or weight of the structure built on top? All of these things must be taken into account when choosing the right mix.

source: http://www.topform.ca/