Flawed tests for concrete need rethink
The allegation of faking concrete test results for the Hong Kong-Zhuhai-Macau bridge has raised public concerns about this multi-billion-dollar project.
The focus has been on those who may be responsible for this with arrests having been made. What we should be asking is how such an incident could happen in the first place, if the government’s quality assurance procedure had been properly implemented.
Traditionally, concrete tests in Civil Engineering and Development Department (CEDD) contracts have been carried out by the Public Works Central Laboratory (PWCL). To ensure the testing quality, technical staff from CEDD must be present to witness the making of concrete cubes and the storing of these cubes in the curing room for future testing. At the date of testing, the CEDD technical staff will deliver the samples to the testing laboratory and witness the testing.
If this quality assurance procedure is followed, any faked test results or anomalous test samples can be discovered immediately at the date of testing, rather than being discovered a year later. Moreover, there is no way a contractor can fake test results or bring in other samples as the curing room will be locked at all times and the contractor is not allowed to enter without any prior approval.
I understand that in recent years, because of a heavy workload, the PWCL has contracted out a lot of testing work to commercial laboratories.
I am not sure if they have also contracted out the “quality assurance” part. Should this be the case, then it is really disastrous, as there is no direct and immediate contact.