Supertrees: Greening the concrete


Gardens by the Bay is being constructed as a new waterside park in Marina Bay, the southernmost extension of Singapore's downtown district. The park will be a vibrant green space in the city, for the enjoyment of Singaporeans and visitors. Holcim Singapore is delivering green, self-compacting, high-early-strength concrete for the park's supertrees – tree-like structures that will be home to enclaves of flowering climbers, orchids, and ferns.


The 54-hectare Bay South, designed by the UK-based landscape architecture firm Grant Associates was targeted for completion by the end of 2011.


Bay South embraces tropical sensibilities and environmental sustainability. Bay South is an example of how garden design has evolved beyond landscape architecture and horticulture to include a multitude of disciplines ranging from architecture to structural and environmental engineering.


The overall design concept draws inspiration from the orchid, a plant that evokes images of the tropics and is representative of Singapore. Underlying the concept are the principles of environmental sustainability. From the outset, a concerted effort was made to plan and design for sustainable energy and water use, which further extends into a sustainable web that incorporates floral and faunal diversity.


Eternal spring at the equator
Bay South features two cooled conservatories, called Cloud Forest and Flower Dome, which replicate the tropical highland and Mediterranean environments. The conservatories provide the opportunity for visitors to view cooler-climate plants and flowers in equatorial Singapore, in an eternal spring setting.


The thematic gardens in Bay South will showcase the best of tropical horticulture and garden artistry, and highlight the relationships between plants and people and plants and the planet.


Vertical gardens up to 50 meters high
The supertrees are tree-like structures 25 to 50 meters tall. They support vertical gardens of flowering climbers, orchids, and ferns, and their canopies provide shade and shelter. A treetop lounge crowns the tallest supertree, and an aerial walkway provides visitors with breathtaking views of the gardens. At night the supertrees are lit to provide an attractive spectacle. Located at the heart of Bay South, they are a fusion of nature, art, and technology. Some have environmental functions such as rainwater harvesting and solar energy collection. Some are integrated into the conservatories and serve as air intake and exhaust towers.


Special concretes
Holcim Singapore is supplying Holcim Green S for construction of the supertrees. This is a selfcompacting high-early-strength structural concrete with the sand partially replaced by washed copper slag.


Since January 2009 Holcim Singapore has delivered more than 3,000 cubic meters of concrete to the Bay South jobsite.