Holdfast Training Services Trial Blog

Progress on site has been fairly significant this week. We have finally completed the Ground Floor! Aside from now being well and truly above ground level, which is excellent for morale, it also means that I no longer have to walk up and down a multitude of steps to access the decks (I have seen my weight increase to my normal fighting weight, so it is either the lack of steps at work, Nicky is baking more, the stress levels have decreased, or a combination of all 3).

The addition of a Project Manager to the South Block team has been a big injection of capacity. The fact that he has come from Leightons, JHG’s parent company may suggest that ‘Mother’ is beginning to take interest in her wayward child, and is reinforcing the project to ensure the success of her investment.

The PM has immediately made an impact at the subbie contractual level. Crown (Concreter) is a notoriously difficult subcontractor to deal with and have point blank refused to pour concrete some days stating that they do not have the manpower. As the concrete pours dates are promulgated daily for 2 days in advance I don’t see this as a valid excuse. It continues to happen though, until after a frustrating day for supervisors and engineers trying to coax Crown to pour some columns that would enable WCF (Formworker) to continue work the following day (Crown and WCF do not get along well), the PM waded in. I’m not entirely sure what he said or promised (I know pizzas were ordered) but not only did they pour the 3 columns we required, they also worked late to 8pm and poured every single column that we had formed, they even brought in an additional mobile pump to get the job done! This was a big win for us as it opened up several additional work fronts and released column forms to prepare for the 1^st floor.

A similar issue arose the following day, but this time it was resolved by the issuing of a site instruction to the concreter to pour the upper basement to ground floor ramp regardless of weather conditions. Though the issuing of a site instruction appears to be a caving in to their contractual obligation to pour concrete in all conditions, the site instruction will now be debated at commercial level to decide whether it gets paid or not – I suspect not. Crown’s argument was that the weather (light rain) would not produce the specified finish, correct; but does not alleviate them from poor concrete placement. The contract states “The concrete placement subcontractor is responsible for the finish of the concrete in all conditions, including rain,” and also that the “Concrete subcontractor is obligated to pour concrete regardless of the weather, except in heavy rain,” The latter is a little vague as ‘heavy’ is not quantified but from my objective opinion, and from brief discussion with Richard Farmer back at the Mother-ship, JHG should have no mercy for the subbie in regards to rain – it’s worse in the UK!

In the foreground the drips from the slab above have ruined the surface texture. The remainder of the slab has the (now standard on NCH) golfball effect. You can also see the water runs and to a lesser extent the surface undulations above the grade change.

Core C was my second pour on the job, way back in March, and though all appeared to go well on the day, it was an unmitigated disaster inside the core walls. To add some perspective to this and to put up my own responsibility umbrella, I was handed responsibility of the pour 30minutes before it was due to start. The reinforcement was already installed and checked, the shutters were closed, and the concrete was on the road. The issue was in my opinion one of design. The walls were 400mm thick and heavily reinforced, especially around the header-beams and jack pockets. In some places it was later found that the concrete physically couldn’t get past the reinforcement to the form below creating voids and exposed reinforcement in almost every cell of the core. The structure has now undergone an extensive survey using a mixture of cored samples and scanning costing in excess of $120,000. The rectification work is yet to be completed but will certainly involve the breaking out of large sections of wall (1m squares) to be re-poured.

One of the less significant defects in Core C. This reinforcement has 30mm cover to the surface but due to poor vibration and closely spaced bars, concrete couldn’t get through.

The remediation work has the added issue that it has held up progress on the South floors and subsequent floors that tie into the core will require additional back propping to prevent additional load being transferred to the walls. The JHG solution to the Core C problem was to draft in an engineer with the sole responsibility for ensuring that it didn’t happen again. The next lift of Core C was poured last week, and even with all the additional resources and quality ensuring measures in place, there are still several areas of exposed reinforcement. I think this issue could have been engineered out at the design phase as it should have been fairly clear that the shear volume of steel in the wall was going to make concrete placement difficult. Provision could have been made for either an increased wall thickness or a more sympathetic arrangement of bars in areas of high reinforcement. The concrete is already at a high slump and using a 14mm aggregate to ensure it has the best balance between consistence and strength. This problem will continue for the following lifts unless a preventative solution can be found to minimise the poor flow of concrete around the steel.

I have got myself involved in the procurement package for the concrete precast panel walls. It is a relatively small package at $700,000 but has given me the opportunity to follow the process from initial tender to where it is currently stalled in the commercial department. I was a site representative at the initial interviews with the supplier and the installer and am looking to maintain involvement throughout the process until the phase ends in early December. Time is flying by.

In other project news, and I suppose related to the arrival of a few Leighton managers, is the recent Leighton’s audit of the project that was, I assume, somewhat scathing as it has had the effect or removing the Commercial Director of the project and the General Manager for the Western Australia Region has ‘resigned’. This has also induced a further 2 senior commercial administrators to resign.

Thanks to Mike/Richard for the blog on the shearing of bolts on Reinforcement connectors. I spotted the connectors whilst wandering site and ‘reminded’ them that the heads were supposed to shear off. Luckily they were designed to shear; I had to check when i got back to the office.

ANCON MBT Couplers. This connection was intended to allow the column starters to be replaced at a later date (after the bulk haulage road was finished with). A change in plan meant that it was no longer necessary to do this but we had already gone too far.

In other news, Nicky and I have finally booked a holiday to NZ to do the classic campervan tour of the South Island, and hopefully meet up with my cousin from Wellington. We are also doing the largest swing in the world (nothing dodgy) that we saw on the Australian TV show “The biggest loser,” If it can hold the fatties, I’m sure it will be OK for us! We are off to Sydney to catch up with the Bainger’s and take part in the Tough Mudder event.