Experimental evaluation demonstrates enhanced mechanical strength and weathering resistance in heritage sandstone, indicating effective consolidation without altering stone appearance.
Key Points
To evaluate the mechanical reinforcement, durability, and physical compatibility of anion-exchange synthesized nanolime for consolidating weathered sandstone at the Dazu Rock Carvings.
Synthesized calcium hydroxide nanoparticles via a one-step anion-exchange route, followed by mineralogical and morphological characterization using XRD and TEM/EDS.
Assessed treated sandstone specimens using colorimetry, porosity, permeability, uniaxial compressive strength (UCS) testing, and nanoindentation mapping.
Subjected specimens to accelerated wetting-drying and hygrothermal-salt aging alongside in situ Leeb hardness monitoring over 100 days.
Synthesized nanolime formed 50–100 nm hexagonal portlandite platelets that increased mean sandstone UCS from 37.35 to 47.00 MPa without significant alterations in color, porosity, or permeability.
Accelerated aging revealed that nanolime-treated sandstone retained higher hardness and elastic modulus compared to untreated controls and traditional lime water treatments.
In situ field monitoring demonstrated surface hardness recovery within 24 hours of application and sustained strengthening throughout 100 days in weathered zones.