Abstract:
In this study synthetic fine and coarse zeolite pellets were chosen in the development of air lime–metakaolin
mortars for repairing ancient masonry to be used in conservation and restoration of cultural heritage.
Synthetic zeolite was used due to their particular water adsorption properties and act as an artificial
pozzolan promoting the development of hydraulic phases.
Physical, chemical, mineralogical and microstructural tests were accomplished to characterize the
materials used in mortars’ preparation.
Flexural, compressive strength and dynamic modulus of elasticity tests were performed in mortars at
28, 90 and 180 days of curing. Incorporation of both fine and coarse zeolite pellets caused improvement
of mechanical strength of mortars. The highest flexural strength value ( 0.5 MPa) was achieved in both
mortars with fine zeolites pellets at 90 days and 20 and 30 wt.% metakaolin, and coarse zeolite pellets at
180 days and 30 wt.% metakaolin as lime replacement. 1.0 MPa was the highest compressive strength
value obtained at 180 days for mortars with both fine zeolite pellets and coarse zeolite pellets, with 20
and 30 wt.% of metakaolin, respectively.
Elasticity modulus ranged from 2.3 GPa to 3.9 GPa confirming the high deformation capability of these
mortars.
Zeolite pellets type A is a promise synthetic material that could be successfully used in air lime–
metakaolin render mortars for applications in the conservation and restoration of cultural heritage.
