Author
SOUSA, H.; SOUSA, L. C.; CASTRO, C. F.; ANTÓNIO, C. C.
Faculty of Engineering/University of Porto – Portugal

Abstract
The concerns with masonry building envelope performance, particularly thermal efficiency, are causing important changes to masonry construction, mainly in south European countries where traditionally the mild winter climate justified the use of a moderate thermal masonry wall performance. The new European Directive regulations require different solutions. To answer these new challenges, two approaches are available; to add higher thicknesses of thermal insulation in association with current masonry walls, or to change masonry units, combining improved thermal insulation with enough mechanical resistance. This paper describes the recent development of two new masonry systems, based on light density clay units and lightweight concrete units, intended for construction of large single leaf external walls without thermal insulation materials. A detailed analysis and optimization has been performed by FEM, considering both thermal and mechanical points of view. Experimental characterization has been carried out to confirm some important characteristics. The concerns with productivity and ergonomics are also considered as they affect cost.

Key words
large blocks systems, thermal performance