MOBILI, ALESSANDRA1; BITETTI, MICHELE2; TITTARELLI, FRANCESCA3

1Engineer, PhD Student, Department of Sciences and Engineering of Matter, Environment and Urban Planning, Università Politecnica delle Marche, Ancona, Italy a.mobili@univpm.it

2Master Degree in Ingegneria Edile-Architettura, Università Politecnica delle Marche, Ancona, Italy michelebitetti.83@gmail.com

3Associate Professor, Department of Sciences and Engineering of Matter, Environment and Urban Planning, Università Politecnica delle Marche, Ancona, Italyf.tittarelli@univpm.it

With respect to environmental sustainability for the rehabilitation and restoration of masonry buildings, the properties of geopolymeric mortars were studied and compared with those of traditional cement-based ones with the same mechanical strength class and workability.

To this aim, four different geopolymeric and cement mixtures were manufactured in order to obtain mortars belonging to R1  10MPa, R2  15MPa, R3  25 MPa and R4  45 MPa strength classes.

In particular, geopolymeric mixtures were prepared with a sodium silicate/sodium hydroxide equal to 1:1, by using different concentration of the solutions, and sand/fly ash proportion equal to 2.7:1. The respective four cementitious mortar mixtures were prepared with water/cement equal to 0.5, 0.65, 0.9 and 1.1 by weight.

Geopolymer mortars behave better than cement ones in terms of lower modulus of elasticity, higher water vapour permeability, lower capillary water absorption and higher resistance to salt crystallization.

Keywords: Geopolymer, cement, mortar, fly ash, masonry rehabilitation, mechanical properties