Investigate of degradation mechanism of paint for building surfaces in Singapore

• Main Author: Soh, Liang Bin
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/60966
• Institution: Nanyang Technological University

Cool paint provides a profound heat reduction effect by interacting with the sky to dissipate heat from the building, allowing the building’s interior to be cooler than ambient air. This paint encompasses the technology to reflect solar irradiation from the sun on building surfaces, which in turn helps to keep the surface temperature of the building to a minimum. The main problem lies in the degradation of the paint, causing it to deteriorate after prolong usage. Along with the accumulation of dirt and soiling, the paint loses its reflectance property and hence its effectiveness in curbing building heat gains. This paper aims to investigate the different degradation mechanisms of the paint on building surfaces. This will enable the effective period of the paint to be determined. As the effect of degradation of the paint from the natural weathering process takes a rather long time to observe, accelerated weathering system was employed to reproduce the weathering process in a reproducible controlled environment. In this study, a commercially available cool paint was applied to three different substrates materials commonly found in building surfaces in Singapore: Stainless steel, Concrete and Aluminium. Carbon soot and real dirt deposition on these substrates were conducted to examine the effect of contamination as a degradation mechanism. The QUV Accelerated Weathering testing was used to provide a laboratory simulation of the damaging forces of weather in an outdoor environment. In general, reflectance of the painted sample decrease against time and this is proven in both natural and accelerated weathering testing. There is an estimated 2% to 6% decrease in the reflectance over the course of two years. In accelerated weathering duration, this is approximately eight weeks of testing in the QUV machine. It was also found that the concentration of dirt accumulation has a significant effect on the degradation of the paint. Moreover, cool paint on certain substrate has a higher performance than others.