Nearly every building, landscape and piece of construction in China uses insitu concrete (on-site poured) concrete. There are many issues with on-site concrete include
Pollution: On site pollution, waste, noise, trucks, on-site mixers, soil compaction, water pollution
Inefficient Usage: Concrete goes off (bad) quickly if not used within 20-30 minutes, transport needs to be fast (causing issues with speeding trucks, pollution, etc), testing is lacking and can cause waste.
Finish: Final finishes can be too rough or inaccurate, requires rendering/screeding to get a good final finish.
Today, I read that Shanghai will start using Precast Concrete (PC) for many of its residential to save on energy, construction pollution and noise, however it will raise costs. I think it’s good to see Shanghai embracing a technique used across the world to construction various buildings including residential, commercial and industrial. The other reason as an landscape architect I am happy to see this occurring is that it will flow on to other industries including landscape and thus allowing designers to create interesting shapes and finishes in the landscape.
The move to Precast Concrete will also be good for Shanghai as it will reduce the number of large concrete trucks in the city and also eliminate many of the concrete plants along the Huangpu River and Suzhou Creek that although interesting as an industrial landscape can cause water, soil and noise pollution. Also precast concrete can save time on-site, if the precast is ordered a floor can be built quickly. In Australia, precast is used for housing and office buildings but the biggest benifit is in build factories where the footings can be completed in advance and then the frame and precast can be completed in a few days.
The Shanghai Government will be promoting Precast Concrete throughout the city over the next three years and encouraging construction companies to move to precast systems, I am hoping it the move also occurs in the landscape industry over the next 3 years.