Test work to verify concrete at the centre of an investigation into alleged falsification of original strength tests on the Hong Kong-Zhuhai-Macao mega-bridge will be completed by October.
In May this year, Hong Kong’s Independent Commission Against Corruption (ICAC) arrested two senior executives and 19 staff members from a contractor working for the government’s Civil Engineering and Development Department (CEDD) for alleged corruption, in relation to claims of false concrete compression test reports for the bridge.
Anomalies were found in 346 concrete cube tests carried out by the lab in question from January 2013 to March 2017. The affected structures include 179 above ground or sea level structures, 96 below ground or sea level locations and 71 non-structural locations.
Of the 179, 158 have been tested with non-destructive rebound hammer tests (RHT) and the Hong Kong Highways Department says all have passed. The remaining 21 require additional access to be set up, which will prolong the testing programme.
Tests on concrete cores taken from the 179 locations will also be carried out.
Where RHT cannot be carried out on the 96 below ground or sea level structures, the department is carrying out tests on 116 concrete cores which were taken from 5% of the piles as a requirement during construction. Each core is split into three samples and their compressive strength tested. As of 5 July, 43 have been tested and each has passed, said the Highways Department.
Non-structural locations have not been tested.
The department has also carried out hammer tests on the concrete in a further 3,000 stress critical locations of the structures. All have met the standard, it said.
Results from the tests are expected before the end of October.
The Zhuhai-Macao Bridge is a massive £1.8bn project which will link Hong Kong with Zhuhai City in Guangdong Province and Macao in China. The project includes a 29.6km dual three lane carriageway running across the sea on a series of three cable stay bridges connected by viaducts, plus a 6.7km tunnel, and artificial islands for the tunnel entrances portals.