Climatic response of rice soup mortar used in heritage structures under the influence of humidity and temperature

Abstract

The objective of this study is to examine the role of rice soup mortar in three different climate zones, each characterized by varying temperature and humidity. Organic analysis techniques, including Fourier transform infrared spectroscopy (FT-IR) and gas chromatography–mass spectroscopy (GC–MS), were used to identify the phytochemical compounds present, such as fatty acids, hydrocarbons, aldehydes, and alcohols. Advanced analytical methods, including X-ray diffraction (XRD), thermogravimetric–differential thermal analysis (TG–DTA), and field emission-scanning electron microscopy (FE-SEM), were employed to investigate the hydrated phases and microstructure of the organic lime mortar samples. Regarding compressive strength, Zone 1 outperformed the other zones, with the S2 sample (2% concentration) exhibiting the highest compressive strength of 2.63 N/mm². The carbonation initiated the calcite and aragonite formations, whereas portlandite, tobermorite, afwillite, and anorthite were hydration products. At low temperatures, the transformed polymorphs are calcite, while at high temperatures, the polymorphs are aragonite and calcite. Overall, Zone 1 excelled in all aspects, indicating that temperature and humidity significantly influence the strength, mineralogical composition, and morphological formation of the mortar.