Amylopectin extraction from kernels as a sustainable additive for enhancing the performance of natural hydraulic lime mortar for restoration applications

Abstract

This article presents an innovative study that experimentally investigates the role of amylopectin, extracted from kernels, on the mechanical, physical, and durability properties of natural hydraulic lime (NHL) mortars. Polysaccharides of amylopectin play a major role in increasing the workability of the additive-modified mortar. The amylopectin-modified mortar enhances its compressive strength by 1.68 times compared to the reference mortar. The amylopectin-modified mortar improves its mechanical properties without compromising water absorption and porosity, thus preserving the breathability of the restoration mortar. Amylopectin enhances the hydrophobic property of NHL mortar, forming an outer layer that is resistant to water and salt deposition. The modified mortar’s moisture-holding capacity improves carbonation and reduces drying shrinkage. The polysaccharides of amylopectin enhance the carbonation, regulate the growth of calcite crystals, and result in a denser microstructure, leading to enhanced strength gain. We have also studied the microstructure and morphology characteristics of the modified mortar using XRD, FT-IR, and SEM. We can further extend the investigation to examine the crack capacity of this amylopectin-modified NHL mortar.