Contamination Crisis – UNSW
G’day gents (had to do it). Australia has experienced a record breaking 23 days of continuous rain, so I have managed to maintain my pasty complexion. Quick orientation – My site is at the University of New South Wales where there are effectively three separate projects. The main event is the Science and Engineering Building (SEB). The substructure consists of a contiguous pile wall (CFA piling), followed by a bottom-up concrete sub/superstructure. The Roundhouse is a refurbishment (including significant structural steel strengthening) of the University’s precious student union. It’s the oldest building on campus and there is a big push to complete before Christmas for obvious reasons. The Hilmer building is a M&E services fit out project.
Contract arrangements.
Shock – none of the projects has a formal contract. A letter of intent was issued only last week to continue with works on the Roundhouse and the SEB contract is still being negotiated (current works including piling mattress form part of the early works letter of intent). Multiplex are pushing for a Design and Construct (D&B) contract, but the client wants more influence via a managing contractor contract. In addition, the SEB still doesn’t have Development Approval (DA) from the council and the delivery of the piling rig has been pushed to the right by another 2 weeks as a result.
Contamination Issues.
The Geotechnical Engineer found no evidence of ground contamination during his GI. However, whilst the SEB site was being excavated to formation level in preparation for construction of a piling mattress, bonded asbestos was identified on site (believed to be old formwork panels from previous construction that were dumped in an excavation!).
There were 2 potential remedies. First was to employ a hygienist to sift through all excavated material and inspect each load as it left site. Or alternatively just remove the first 1.5m from across the entire site and classify the whole lot as General Solid Waste Asbestos (GSWA). Surprisingly, this was only $2/tonne more than normal GSW and therefore a mere $26,000 of additional cost. The total effort was 13, 000 tonnes of waste material that required approximately 600 “truck and dogs” (Aussie slang for a truck with a large 12 tonne skip on the back). I was involved in producing high risk workshops and removal control plans for the site. Clearance certificates were issued for the site and piling mattress construction has begun.
On the roundhouse, the existing steel structure was covered in lead paint (for fire proofing I assume). This was obviously identified and considered in the programme, but the length of such a process was hugely underestimated. The programme is now 4 weeks behind and only 30-40% of the paint has been removed. The first option considered was to sand blast it off. However, this idea did not survive very long due to the clean-up effort required and the difficulty of containing air particles. The second option proved mildly successful and involved soaking the lead with a gel before blasting off the lead with dry ice pellets in a spray gun. See dry ice pellets and gun operator below.
However, although successful, it is a painfully slow process, even after reinforcements arrived with additional guns. Yesterday the subcontractor switched to a soaked paper peel that is applied overnight before being peeled off with ease, bringing the lead with it, the next morning (very effective). Unfortunately, whilst everyone was high-fiving each other, some of the solution dropped onto the leg of one of the workers and it burnt straight through his PPE! All work has been stopped until a new Safe Work Method Statement (SWMS) is produced by the subcontractor and reviewed by MPX. That is tomorrow’s problem…….
Holdfast Training Services Trial Blog 
Allan,
In the UK the paint I think you are referring to is called Intumescent Paint. As you said it provides fire resistance for exposed columns that are not protected by other means such as concrete encasement. Normally it’s put onto steel beams and columns as part of the workshop fabrication process and takes multi procedures to get it right. However, due to its thickness it is usually left off the parts of steelwork that require a steel to steel connection, such as the base of column splices. Once on sight these areas are then patched up. In summary, Its a nightmare to put on so it’s interesting to hear that its even worse to get off . I don’t envy you guys that task but its probably a decent ICE consideration under the sustainability field.
Cheers Tom, you’re spot on. I did a little more digging today and confirmed that it was for fire rating. The entire steel structure is being reinforced with new steel plates that will be welded onto the original sections. This to increase their capacity in order to carry the plethora of modern services that are being installed. For some reason they are painting the current structure before the new structural steel installed, which as you say, means the painters are having to leave gaps all over the place so that the new plates can be welded!