MAINTAINABILITY OF TIO2 COATING IN TROPICAL CONDITIONS

Abstract

In Singapore, developers are estimated to spend up to $320,000 per annum to maintain the aesthetic appearance of a facade. Application of TiO2 coating translates to long term cost- savings through reduced cleaning frequency, reduction of water consumption and reduced labour costs. Developers and A*STAR labs have invested in TiO2 coating, but it is still not widely used on facades in Singapore due to high initial cost and inadequate knowledge on the performance of TiO2. In Japan, high labour costs and high aesthetical standards are the main attributing factors to widespread usage. Hence, TiO2 coating is the solution to alleviate increasing cleaning cost due to labour shortage in Singapore. As such, it is necessary to investigate the technical problems and economic components to highlight factors for efficient technical and economic performance of TiO2 coating. This study only focuses on concrete and glass buildings as metal cladding have proven to be effective substrates technically and economically in the long run. Major technical problems of concrete and glass facades are investigated through interviews with 10 professionals, extensive literature reviews and site investigation. Based on extensive site investigation and literature reviews, 9 defects were identified on TiO2 coated concrete and glass buildings. 15 parameters resulting in inefficient performance were assessed with site investigation and interviews. Further validation was performed through one-sample t-test to generate 13 significant parameters to be collected in the handbook on maintainability of TiO2 coating. By doing so, possible causes of the defects are minimized. Life cycle cost analysis investigates the potential cost savings generated from the investment of TiO2 coating in the long term perspective. Different application and maintenance strategies were compared to determine the most cost-effective strategy. For concrete and glass buildings, zero savings and savings up to $222,000 were derived respectively at the end of five years. Despite zero savings being generated for concrete buildings, users need to consider that inflation rate was not taken into account, which do not reflect the exact cost savings at the end of five years. Water –savings and wellmaintained façade far outweighs the zero cost savings. From the study, final deliverable is a handbook on maintainability of TiO2 coating in tropical condition. It is the first guide in Singapore that provides a comprehensive guide

IV to users throughout design, installation and maintenance stage. During the design stage, factors on location and design features of building envelopes are emphasized to advice designers on the optimal installation location. Recommended flowchart highlights to users on the crucial factors to be considered during each life cycle stage. During installation stage, integrated system focuses on proper training for optimal application standard. Installation checklist is in place for suppliers to make sure correct procedures have been completed before installation. For maintenance stage, recommended preventive measures are highlighted for maintenance personnel to recognize the types of maintenance to be undertaken. All in all, introduction of this handbook ensures efficient performance of TiO2 coating by addressing vital steps to be considered during each life cycle phase, hence resulting in cost savings and environmental benefits. Contributions to academic research are made through the analysis of defects and its parameters, which expands on the current knowledge of how TiO2 coating performs on concrete and glass buildings. The current database acts as a foundation for future researcher to build on. Major contribution are made to the industry through the development of a handbook which provides a practical decision-making tool for end users to decide on the suitability of TiO2 coating right at the start of projects.