Usually the blocks are produced with concrete block making machine by using light concrete and according to consolidated production technologies …
– Using heavy or light aggregates with uniform size to create a honeycomb mass characterized by a structure with large voids inside, about half the weight of a normal concrete, packaged with the same aggregates;
– Creating gaps in the concrete mass before the hardening chemical reactions begin, introducing foaming additives;
– Eliminating heavy aggregates from the concrete mix and inserting cellular structure aggregates, such as expanded clay, pumice or slag from high ovens.
In general, a reduction in the weight of the blocks increases their thermal properties, but at the same time reduces the compressive strength.
Use of concrete blocks
The fields of use of concrete blocks are numerous and diversified, starting from the blocks based on heavy aggregates, for the construction of external bearing walls plastered and protected from atmospheric agents.
For the execution of external or internal non-load-bearing walls and partitions, the blocks with light aggregates and those used for covering are used, so as to ensure the stability of the color over time and create a particular surface graphic effect; the final appearance of the masonry varies, then, according to the surface treatment to which it is subjected.
Finally, the formwork blocks, having different and original shape and quality characteristics, such as to be used in particular processes such as the construction of retaining walls in which the blocks act as a disposable formwork.
Properties of masonry in concrete blocks
Based on the use of concrete blocks and the function that the masonry must perform, well-defined properties are required such as mechanical resistance to compression, impermeability and thermal insulation. The compressive strength of block masonry depends on the two elements that make it up, that is concrete and mortar blocks, and on the quality of the installation.
Accurate realization and finishing of the joints is essential for good wall waterproofing; it follows that when the joints have a reduced thickness, the impermeability can be compromised both by exposure to severe conditions and by lack of protection.
The block of concrete intended for the visible face is industrially produced according to the aesthetic result to be obtained and the particular masonry that must withstand the most varied environmental conditions during its useful life. The color of the blocks is obtained by using white cement and colored aggregates or, alternatively, gray cement and chemical additives that are added when the blocks are mixed.
Great importance is given to the realization of the joints and, therefore, to the mortar that can be simply shaved flush with the wall. Give them a concave shape. A pleasant appearance of the wall will be obtained, the surface of which will be more waterproof and durable.