The construction of new facilities for Penrose glass manufacturer O-I New Zealand (formerly ACI Glass Packaging) required Stevenson Concrete to create special mixes and to regularly pour concrete in the middle of the night in a physically challenging environment, under tight time constraints.

The project commenced in December 2009 when Stevenson Concrete was subcontracted by Harbour Construction Ltd to supply special concrete mixes to the project. Three new buildings, cold end storage, furnace and lehr, and a new batch house were being constructed, all of which have used Stevenson Concrete.

“We did midnight concrete pours regularly over summer,” says Stevenson Concrete Product Manager Brent Atkinson. “We worked very closely with our client Graham Hawkins at Harbour Construction. The results we’ve achieved are the outcome of a tremendous team effort. Harbour worked under huge pressure. When Graham said he needed concrete, we gave it to him – whatever the time of the day or night.”

The first ‘heat-up’ took place in early September 2010. Stevenson completed concrete pours to the last of the pavement areas around mid-September.

The pavement mix design was a 50MPa concrete designed to cure to 25MPa in 16 hours.  “To minimise the effect on the operation of the existing furnace, we were given a maximum 24 hours’ access to feed the plant raw materials over the completed pavement areas,” says Graham Hawkins, Construction Manager, Harbour Construction. “This gave us only eight hours to finalise site preparation and to pour the concrete before curing. Stevenson Concrete’s expert design and excellent service made this possible. I’ve used them on previous projects and will continue to use them. Brent Atkinson gets things sorted quickly for us.”

“One of the technical challenges faced by Stevenson Concrete was creating a mix design that met the strict Australian 32MPa design requirements,” says Brent Atkinson.

Cisco 640-822

“Our consultant Concrete Technologist Michael Khrapko helped us to develop special mixes for the project. These had to achieve a low heat of hydration due to the magnitude of the concrete pours, which ranged between 700mm to one metre in depth. Golden Bay fly ash was required for the mix to provide a 25 per cent cement replacement and this proved to be in short supply. Another challenge was achieving a 650 micro strain on a Comfloor (composite steel flooring system). We’ve also been working on a site in which the old glass furnace has continued to operate.”

Health and safety compliance was stringent on the site, with everyone obliged to wear safety glasses, hard hats, long sleeves, long trousers and gloves, regardless of the season. Potential hazards included broken glass and fine glass dust. O-I is the only manufacturer of glass bottles and jars in New Zealand, producing around 50,000 bottles/jars per hour.