The concrete usually used in making concrete blocks is a mixture of water, sand, Portland cement and gravel . These components combined produce a light gray block with a fine surface texture and high compressive strength.
Generally, the cement mix used to make blocks has a higher amount of sand and a lower amount of water and gravel than the concrete mixes used for general construction.
By contrast, lightweight concrete blocks are made by swapping gravel and sand for expanded clay, shale or slate . These last elements are generated by crushing some raw materials and subsequently subjecting them to high temperatures near 1093 ° C. At this temperature level, the materials swell or expand due to the rapid generation of gases caused by the combustion of the material. organic that is trapped inside.
Commonly a light or light block weighs between 10 and 12.7 kilos, and is used to build walls, walls and partitions that do not resist much load.
Regardless of the basic materials, the concrete mix used to make blocks can also contain some chemicals, which are known as additives . These elements help to modify the cure time, increase compressive strength or workability.
It is essential that the additives comply with the ICONTEC 1299 “Chemical Additives for Concrete” standard.
The compound can contain added pigments to give the cement blocks a uniform color throughout their surface, or the surface of the blocks can be covered with a baked enamel to create a decorative design or to protect it against chemical attack.