CORPUS Magazine

Waterproofing a city

Hangzhou is situated in an area prone to heavy rainfall and flooding. Basic infrastructure isn’t always up to par with the requirements while at the same time more and more surfaces are being sealed due to Hangzhou’s breathtaking growth rate. Using Elastopave, officials set themselves the goal of waterproofing their city.

Like many Chinese cities, Hangzhou has a problem. The capital of the province of Zhejiang in the east of China is growing at a breathtaking rate and currently has a population of some 9 million. One of the consequences of this growth is that more and more surfaces are being sealed – building land is precious, so every square meter is put to use. At the same time, the basic infrastructure is often unable to keep pace with the speed of development. The capacity of drainage systems, for example, often lags behind actual requirements. And the requirements in Hangzhou are extreme. The city is situated about 180 kilometers southwest of Shanghai where the Qiantang River flows into the East China Sea. The climate is subtropical and rainy with heavy precipitation all-year round, peaking from April to October during the summer monsoon. As of June, the region is additionally affected by typhoons, which can also bring deluges with them. Serious flooding therefore occurs repeatedly, even within the urban center. Neither the drainage system nor the 500-hectare West Lake in the city center is able to cope with the sheer volume of water.

Even the West Lake can’t cope with the water masses that occur during monsoon season.

Going new ways in surface construction

To tackle this problem and make Hangzhou “waterproof”, the local council is resorting to Elastopave. With its help, the municipality is to become a “sponge city” – a city whose surfaces are capable of soaking up water like a sponge. By 2020, at least 20 % of the city center is to be equipped with the PU system. The Moganshan Road and a cycle path along the popular West Lake were only recently surfaced with Elastopave. For the high-performance product, selected mixes of minerals are bonded with polyurethane to create a strong, water- and air-permeable wearing course. Thanks to an intelligent mix of selected stone, the surface has many interconnected voids – surfaces are no longer sealed and rainwater, given a suitably absorbent substrate, can seep away within seconds. The PU system is thus an efficient and forward-looking solution for the design of plazas, public spaces and paths.

Simple to use – versatile in its applications

Elastopave is simple to use and blends harmoniously into its surroundings thanks to the broad selection of stone mixes. Investment in the new material is worthwhile also because downstream costs due to sealed surfaces – such as drainage charges – are no longer incurred. The PU system is suitable not only for roads, paths, and parking lots, but also for garden design and even indoors. Whatever the application, surface design with Elastopave stands for an attractive appearance, durability, and benefits for the environment. In Hangzhou, at any rate, those attending the G20 summit at the beginning of September were able to explore the city without getting their feet wet – thanks to this high-performance material.

Heavy rain in Hangzhou causes flooding as the water is unable to run off fast enough.

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Elastopave® is a completely new concept for the construction of durable surfaces on paths and plazas. Strong, safe and environmentally friendly. 

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