Corrosive Concrete Halts Construction Work in South China

Pingfan tower

Pingan International Finance Centre, Shenzhen. Source: Emporis

Work on a slew of major projects in the southern Chinese metropolis of Shenzhen has been abruptly suspended following reports that the concrete used for their construction was made from cheap, unprocessed sea sand.

The Shenzhen Housing and Construction Bureau held an emergency news conference on March 15 to announce that it had launched a full-scale investigation into the practice. Their investigations have thus far established that 15 of the 92 concrete-mixing plants in Shenzhen used untreated sea sand as a raw material in concrete which had been sold to local developers.

The use of concrete made from unprocessed sea sand is believed to be highly prevalent throughout the Pearl River Delta area of Guangdong province, one of the primary hubs of industry and commerce in China.

The prevalence of the practice in Guangdong has surprised many observers given its reputation as one of the most developed parts of the country as well as the first to implement reform and liberalization measures under Deng Xiaoping.

Four concrete-mixing companies have already been named by the central government’s media outlets as having engaged in the practice, including one which is owned by Hong Kong-listed company China Resources Cement Holdings.

concrete being poured

Source: BASF

Manufacturers are often inclined to use sea sand in lieu of river sand as an ingredient in their concrete due to the greater expense of the latter as well as its relative scarcity in the Pearl River area. A spokesman for Shenzhen’s Housing Authority said the sand used in the construction of its buildings was obtained via the arduous and expensive process of crushing rocks at a quarry.

The use of unprocessed sea sand as a raw material in concrete is considered highly hazardous due to the large amounts of salt and chloride it contains, which can corrode steel reinforcements and lead to the collapse of entire buildings.

While officials have not made the public privy to the precise number of residential and commercial projects containing the suspect concrete, the scandal is believed to have affected work on some of the most high-profile construction projects in Shenzhen.

Most prominent amongst them is the Pingfan Financial Centre, which at 660 metres is set to be the tallest building in Guangdong province when it is completed.

By Marc Howe
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