Document Type : Original Article
Authors
1
Department of Civil Engineering, Faculty of Engineering,University of Moratuwa, P.O. Box: Bandaranayake Mawatha, Moratuwa 10400, Sri Lanka.
2
Department of Design Studies, Faculty of Engineering, NSBM Green University, P.O. BOX: , Pitipana,Homagama, Sri Lanka
3
Department of Civil Engineering, Faculty of Engineering, Esoft Metro Campus, P.O. Box: No.03, De Fonseka Place, Colombo 4,Sri Lanka
Abstract
Clay has been one of the earliest and most versatile building materials, essential for bricks and as a binder for plaster on earthen walls. Despite advancements in surface coatings, there is limited research on coatings specifically for clay-based surfaces. This study addresses this gap by developing a novel clay coating inspired by ancient Sri Lankan techniques. Key ingredients include Pine gum, Haldummala (Shorea oblongifolia), Dorana (Dipterocarpus glandulosus) oil, and ethanol. Fifteen samples with varying Haldummala concentrations (2–10 g in 2 g increments) were tested. Sample 2, with 4 g/L of Haldummala, showed superior properties: a density of 0.9529 kg/L, 55.48% solid content, 21 seconds viscosity, 10.48% opacity, and 33.5 gloss units at 60°. No peeling, cracking, or blistering occurred after 500 hours of artificial aging in QUV tests. Both natural and commercial coatings showed similar gloss reductions (9–12%) but retained over 80% of their initial gloss, demonstrating strong UV resistance. The natural coating also achieved a permissible VOC content of 3.5 lb/gal. The carbon footprint analysis revealed that the natural coating emitted 1210 kg CO₂-equivalent, 61.9% lower than the 3180 kg CO₂-equivalent of its commercial counterpart. This significant reduction highlights its environmental sustainability. Overall, the new formulation proved to be a durable, eco-friendly, and effective coating for clay-based surfaces, offering a viable alternative to conventional options.
Keywords
Main Subjects
)