Page 16 - SBD 1920_11Sept
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Climate change and rising sea levels threaten our very existence. As a low-lying nation, there is nowhere to hide when sea levels rise. Other small
island nations like the Maldives are already facing risk of flooding, with severe implications. To protect ourselves against climate change and rising sea levels, we will have to invest more.
re ective surfaces on pavements and building facades can lower absorption of heat energy from the sun.
The Cooling Singapore project is led by research institute Singapore-ETH Centre, which was established by the Swiss Federal Institute of Technology in Zurich in partnership with the National Research Foundation (NRF) under its Create programme. It comprises academics from the National University of Singapore, Singapore- MIT Alliance for Research and Technology and TUM CREATE (Technical University of Munich). In addition, there is also a Cooling Singapore Taskforce comprising 14 other government agencies and research institute, including the Urban Redevelopment Authority (URA) and the Singapore University of Technology and Design.
Together with the URA and the HDB, researchers have begun modelling studies to see how different mitigation measures can be applied. It has been found that more re ective roofs can achieve up to a 1.29°C reduction in temperature, new developments can change air patterns and increase thermal stress, depending on weather conditions, and void decks at public housing blocks can have a positive impact. More vegetation may seem to cool the place but it is not always the case, as trees can reduce wind speed and increase humidity.
The project has come up with a menu of 86 possible measures spanning seven key areas - greenery, urban geometry, water features, material and surfaces, shading, transport and energy - to help make Singapore’s outdoor environment cooler.
Principal investigator of the Cooling Singapore project Assistant Professor Winston Chow said, “The urban heat island effect has
been undervalued previously, and this project aims to bring it to the forefront. There are many bene ts to managing it properly, whether it is in the form of cost savings from using less energy; or indirect bene ts of having more greenery in the city.”
Researching New Materials
New materials are being explored in the drive to go green. At the National University of Singapore (NUS), researchers from the School of Design and Environment have found a way to use wood waste to strengthen building materials. The new method combines cement with biochar, a material produced when heat is used to decompose sawdust, to increase concrete’s strength and impermeability.
Lead researcher Dr Kua Harn Wei said that water is usually added to powdered concrete to create a wet mix in a process called hydration. But as water evaporates during the process, the mix is weakened. However, when biochar is added, the mix is better at retaining water, which in turn produces stronger concrete.
Biochar in powdered form also plugs gaps that exist within the concrete mix, reducing water seepage through cracks that may form when it is set. The researchers found that adding biochar strengthened the concrete mix by 20% and its impermeability by 50%.
Using biochar is also environmentally friendly as tonnes of wood waste are produced in Singapore, mainly from furniture factories. In the past, the wood waste would be incinerated or disposed of.
The NUS team is undertaking further research on cement composites to serve wider applications.

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