Alternative Approach for Traditional Slaking and Grinding of Air Lime Mortar for Restoration of Heritage Structures: Natural Polymer

Abstract

Conservation of ancient buildings to make them long lasting is gaining importance. Lime mortars, which exhibit better strength and durability with progression over time, are used for this purpose. This study emphasizes the effect of adopting the traditional method of slaking and adding a natural polymer extract derived from Bilwa fruit. Lime mortars were slaked for different durations of 1, 15, 30, 60, and 90 days. Further, the admixture was added in concentrations of 5% and 10% to the lime mortar mix. The effects of slaking and the incorporation of the natural polymer extract on the fresh state, mechanical, and physical properties were studied. Durability properties in the form of resistance to salt crystallization and capillary action were also investigated. The microstructure of the mortars was examined through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric differential thermal analysis (TG-DTA) techniques. Characteristics of lime mortar have shown improvement as the age of slaking increases. A similar pronounced effect was observed with the addition of natural polymers.