Structural lightweight concrete is a concrete aggregate obtained replacing in whole or in part the ordinary aggregate with an artificial lightweight aggregate formed by expanded clay. The possibility of creating lighter structures such as beams, piles and floors, cast on site or prefabricated, is feasible by replacing the larger parts of the traditional “natural” aggregate (gravel or stones) with an “artificial” aggregate, made up of expanded clay granules.
The closed structure of the aggregate is obtained by integrating the fine part of the material with traditional aggregate and natural sand. Furthermore, by changing the density of expanded clay and the replacement percentage of the ordinary aggregate, it is possible to obtain concrete with variable densities between the limits indicated, with strength levels starting from 15 N/mm2 up to 70 N/mm2.
This concrete can be made directly on site, mixed in concrete mixing plants or at the prefabrication plant. Pre-mixed concrete in bags are also available and are mostly used for smaller interventions, generally in restoration work.
Being among one of the lightest in the range (with a density of 1.400 ÷ 1.600 kg/m3) they are practical and safe for building reinforcement toppings in the restoration of floors and in all those applications that call for a structural casting without over-loading the existing structures.