“If we don’t come to a conclusion, I will make a ruling that evidence has been destroyed,” the labour department’s occupational health and safety manager Phumudzo Maphaha warned.
He heads the three-man commission sitting in Tongaat investigating a collapse of a section of the mall.
It emerged on Thursday that the results of 13 concrete samples taken from the mall had not been presented to the commission.
Two people were killed and 29 injured when a section of the mall, which was under construction, collapsed on November 19 last year.
Maphaha questioned Gralio Precast (Pty) Ltd’s advocate Saleem Khan about where the samples were. Khan said they had been tested by a company called Concrete Testing Specialists.
A visibly annoyed Maphaha told Khan that 36 samples were given to structural engineer Andre Ballack. They were tested by the laboratory Contest in the presence of a member of the commission.
A further 29 samples were given to representatives of Gralio. Sixteen of these were tested by Beton-Lab CC in the presence of Maphaha himself. According to Khan the other 13 were tested by the firm Concrete Testing.
None of the tests by Concrete Testing were done in the presence of a member of the commission and none of the results were submitted to the commission.
Maphaha pointed out that Gralio was informed verbally and in writing that all tests had to be carried out in the presence of the commission.
“Under no circumstances did we say there would be any tests where the department of labour will not be present,” he said.
Khan said he would take instructions from his client and address the commission’s concerns regarding the missing tests on Friday.
The 36 samples taken by Ballack and tested by Contest were taken from one beam and six columns. Only the concrete from two columns met the minimum required strength of 24 megapascals (MPa).
Ian Topping, for the municipality, told the inquiry tests of concrete slabs carried out by Contest prior to the mall’s collapse showed that of the 64 samples taken from the concrete that Gralio mixed on site, only 14 met the 30 MPa requirement.
He said of Contest’s 36 tests three missed the 30 MPa requirement with readings of 29 MPa.
On Wednesday the commission heard that some of the concrete tested had a strength as low as nine MPa.
The commission resumes on Friday.