Miglioramento strutturale ed energetico di edifici in muratura. Studio di intonaci armati termoisolanti privi di cemento

Abstract

The article focus on the development of a one-part alkali activated slag-based lightweight plaster for seismic retrofitting and energy upgrading of poor-quality stone masonry buildings. Two different alkali activated mortars were manufactured by using expanded glass aggregates and air entraining agent in order to guarantee the mechanical compatibility with historic stone walls (28-day compressive strength close to 8 MPa) and, at the same time, a low thermal conductivity by means of a low specific mass (< 1000 kg/m3). Experimental results evidenced that alkali activated plasters are able to provide a 28-day compressive strength equal to 8 MPa and a thermal conductivity of 0.35 W/mK due to density close to 700 kg/m3. Furthermore, by using methylcellulose (MC), modified starch (MS), polypropylene fibers and shrinkage reducing admixture (SRA), the shrinkage of mortars was strongly reduced and excellent adhesion to the substrate, absence of micro-cracks and detachments were achieved.