Natural hydraulic lime mortars with goat and bovine hair fibers for sustainable conservation of heritage structures

Abstract

The natural hydraulic lime-based mortars were modified by the addition of egg albumen and the incorporation of animal hair fibres, specifically goat and bovine, to experimentally assess the influence of natural fibres on their structural, hygric, thermal, and mechanical properties. The primary objective of this research is to design mortars suitable for the repair and restoration of historic buildings, including those listed, that exhibit sufficient mechanical strength, high porosity, vapour permeability, and long-term durability. Such mortars must perform reliably under real climatic conditions and on substrates frequently deteriorated by excessive moisture and salt crystallization. In the investigated mortars, hair fibres were incorporated at a dosage of 2 % by the mass of the binder, while egg albumen was added at 0.2 wt.% of the batch water.