Basalt fiber reinforced natural hydraulic lime mortars: A potential bio-based material for restoration

• Properties of fiber reinforced hydraulic lime-based mortars were investigated.
• Three basalt fibers of dissimilar aspect ratios and shape were used.
• Results confirmed that basalt can significantly affect the behavior of the mortars.
• Fiber reinforcement was effective in imparting post-peak stress carrying ability.
• Results highlighted the significant role played by the basalt/mortar interface.

Physico-mechanical properties and the microstructure of basalt fiber reinforced hydraulic lime-based mortars were investigated. Three different mortars were characterized, one based on natural hydraulic lime and a siliceous aggregate and two dry premix of natural hydraulic lime, selected inert aggregates and selected crushed bricks and tiles. The effect of three different types of basalt fibers at two contents on mechanical and water absorption through capillarity was investigated. Fiber reinforced mortars showed a marked improve in post-cracking behavior and compressive strength which was found to depend strongly on the type of matrix and basalt fiber. Reinforced mortars exhibited a lower capillary water absorption coefficient than the reference mortars regardless of type of matrix and basalt fiber. Despite the promising results, the study highlighted the need to optimize both the surface treatment of basalt fibers and their content in the mortars with a view to defining a suitable material for masonry restoration.