Lightweight blended building waste in the production of innovative cement-based composites for sustainable construction.

• The waste incorporation up to 25 vol.% allows structural application of concrete. • Considerable lightening and high thermal performance of composites were observed. • Designed concretes may find usage for special filling and flooring applications. • The waste application mitigates negative environmental impacts. Intensive quarrying of natural non-renewable resources belongs to the actual topics related to the dynamically developing construction industry worldwide. However, at the same moment, an appreciable quantity of construction and demolition waste (CDW) is generated, from which the primacy to concrete, ceramic and masonry derived materials is attributed. These are already traditionally applied in concrete manufacturing as supplementing and filing materials due to their good recycling ability. Nevertheless, a number of material blends which separation is complicated or highly financial demanding still remain and thus burden our environment. This work has been aimed at the effective application of lightweight blended building waste (LBW) in the manufacturing of eco-friendly concretes. Concrete mixtures with the volumetric content 0–100% of the waste blend have been prepared. The influence of LBW on 28 days' water cured samples has been investigated with the application of a wide range of experimental procedures and various instrumental techniques. Performed tests revealed a substantial lightening effect of LBW – leading to hardened concretes with a unit weight of about 760 kg·m−3. On the other hand, a high rate of lightening caused considerable decrease in strength properties of produced composites. However, application of LBW up to 25% can be used to preserve usage of these blended concretes for construction applications. Other performed tests showed excellent thermal performance of waste aggregate enriched concretes, and thus these materials may find usage for special filling and flooring applications with minimum loading of bearing structures. [ABSTRACT FROM AUTHOR]