Concrete Magazine - Volume 54. Issue 02.

concrete vOlumE 54 ISSuE 2 JuNE/JuLY 2010

Eastport Opening GOLDEN BAY CEMENT CELEBRATE OPENING OF EASTPORT FACILITY

Concrete Art GRC PANELS FOR NEW LYNN RAIL TRENCH

Underwater Adventure HOLCIM HELP KEEP 2010 WORLD ROWING CHAMPIONSHIPS AFLOAT

THE MAGAZINE OF THE CEMENT AND CONCRETE ASSOCIATION OF NEW ZEALAND

UPFRONT

concrete MAGAZINE

June marked the end of the CCANZ operational year, and once again the organisation’s output over the previous 12-months has been assessed as a means to judge performance and inform the 2010-11 CCANZ Business Plan.

www.ccanz.org.nz/concrete Editor: Adam Leach

In retrospect the 2009-10 year was very much one of consolidation, not only for CCANZ, but the building and construction industry in general.

During the year CCANZ has continued in the endeavour to maintain and develop market share for concrete through strong industry representation. However, it would be remiss not to acknowledge that the effects of the global financial crisis were felt most intensely over the past year, to the point that many businesses suffered real financial hardship.

Although we have heard the term “cautious optimism” used relatively frequently in economic forecasts for the next 12-months, the building and construction industry is still operating in an uncertain environment. Talk of recovery must be tempered with awareness that major non-residential construction projects around the country are approaching completion, while May consent figures for new residential construction dipped on the previous month’s figures, demonstrating an overall unpredictability.

Against this backdrop CCANZ has consulted closely with our Associate Members – the New Zealand Portland Cement Association (NZPCA), the New Zealand Ready Mixed Concrete Association (NZRMCA), the New Zealand Concrete Masonry Association (NZCMA) and Precast New Zealand Inc (PCNZ) - to develop a 2010-11 CCANZ Business Plan with specific project targets designed to serve the collective interests of all parties within the New Zealand concrete industry.

A distinguishing characteristic of the 2010-11 CCANZ Business Plan is the move away from multiple small-scale projects to a condensed number of projects with broader objectives.

This is most evident in the area of education, training and research. Coupled with developing the next section of the RED BOOK, partnering BRANZ in acoustics and recycled concrete aggregate research, as well as drafting an Acceptable Solution for concrete within Clause E2 External Moisture of the New Zealand Building Code, the 2010-11 CCANZ Business Plan offers deliverables that will benefit the entire concrete industry.

Although you have only just turned the cover of Concrete magazine, I’m sure you will have noticed the layout and design have changed somewhat. Following feedback from key stakeholders we have taken the decision to adopt a more dynamic and contemporary brand to convey the changes that are occurring at CCANZ. The new brand will be rolled out across all CCANZ communication tools, including an updated website, over the next month.

Finally, Cathy Castle, CCANZ financial administrator for over 10-years left the organisation recently. Cathy diligently fulfilled her duties for not only CCANZ, but also the NZRMCA, NZCMA, PCNZ, the Masonry Trades Registration Board and the Construction Industry Council. Cathy will be missed by her CCANZ colleagues, as well as all those in the industry with whom she worked over the past decade. We wish Cathy all the very best.

+64 4 915 0383 adam@ccanz.org.nz Advertising: Adam Leach +64 4 915 0383 adam@ccanz.org.nz www.ccanz.org.nz/ratecard.pdf Subscriptions: Angelique van Schaik +64 4 499 8820 admin@ccanz.org.nz concrete is published quarterly

by CCANZ (Cement & Concrete Association of New Zealand) PO Box 448 Level 6, 142 Featherston St Wellington NEW ZEALAND Tel: +64 4 499 8820 Fax: +64 4 499 7760.

Email: admin@ccanz.org.nz Website: www.ccanz.org.nz ISSN: 1174-8540 Disclaimer: The views expressed in concrete are not necessarily those of the Cement & Concrete Association of New Zealand. While the information contained in the magazine is printed in good faith, its contents are not intended to replace the services of professional consultants on particular projects.

The Association accepts no legal responsibility of any kind for the correctness of the contents of this magazine, including advertisements. © Copyright 2010 CCANZ (Cement & Concrete Association of New Zealand)

Rob Gaimster CCANZ, CEO

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volume 54 issue 2 JUNE/JULY 2010

Cover photo: Inside Golden Bay Cement’s new Eastport bulk cement store.

NEWS Dr Richard Fenwick ONZM CCANZ congratulates Dr Richard Fenwick on being made an Officer of the New Zealand Order of Merit, for Services to Engineering, as part of The Queen’s Birthday Honours 2010.

Dr Fenwick is a leader in the field of earthquake engineering, who has given large amounts Dr Richard Fenwick ONZM of his time voluntarily to share his expertise. He is internationally renowned for his work in seismic-resistant design of reinforced concrete structures, and has successfully mixed an academic career at the University of Auckland with practical design work.

Since his retirement from the University of Auckland in 2002, Dr Fenwick has been extensively involved in unpaid committee work for Standards New Zealand. His research has been incorporated into design codes worldwide, contributing to earthquake safety on an international scale.

STANDARDS UPDATE Specification for Concrete Production – Amendment 2 published Standards New Zealand has published Amendment 2 to Specification for Concrete Production NZS 3104:2003. Amendment 2 is the result of a project sponsored by the New Zealand Ready Mixed Concrete Association to incorporate a new type of mechanism for the testing of weigh systems.

Since the initial drafting of NZS 3104, clauses dealing with weigh scale checking have remained unchanged. In this time there has been a significant introduction of load cell technology replacing the mechanical knife-edge systems that dominated in 1983.

Amendment 2: • Recognises that there is now more than one type of mechanism used for weigh systems (knife edge/lever arm and load cell) • Updates Clause 2.7.3 to take into account testing of weigh systems that are dependent on load cell mechanisms • Corrects minor errors in the Contents • Corrects Clauses 1.3, 2.9.1, and 3.1.4.

DR 1170.0 AMENDMENT 3 TO AS/NZS 1170.0:2002 STRUCTURAL DESIGN ACTIONS PART 0: GENERAL PRINCIPLES DR 1170.0 Amendment 3 to AS/NZS 1170.0:2002 - Structural Design Actions Part 0: General Principles is available for public comment. The closing date for comment on this draft amendment is 03 August 2010.

Both the NZS 3104 amendment and the DR 1170.0 Amendment 3 draft can be downloaded from www.standards.co.nz

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AMENDMENT 2 TO NZS 4229:1999 CONCRETE MASONRY BUILDINGS NOT REQUIRING SPECIFIC ENGINEERING DESIGN Standards New Zealand is reviving an amendment project which originally commenced in 2006. The project was put on hold until a full revision of NZS 3604 commenced as any changes to the seismic zones in NZS 4229 needed to be considered in conjunction with NZS 3604.

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volume 54 issue 2 JUNE/JULY 2010

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concrete 3

Sustainability Award CCANZ is delighted to announce that the 2010 Concrete3 Sustainability Award is now open for entries. The Award provides architects, designers, engineers and/or industry with the opportunity to submit a concrete based product, project or initiative, substantially completed within the past three years, that demonstrates sustainability in either the production or use of concrete.

Previous winners have included Project Century, Lion Nathan’s new integrated manufacturing and warehousing facility in East Tamaki, which made extensive use of recycled glass as aggregate in concrete, and the Northern Gateway Toll Road, of which every aspect, from design through to operation, considered ways in which to contribute to New Zealand’s sustainable development.

Award Categories

Sustainability embraces environmental, economic and social considerations. Each concrete based product, project or initiative entered may relate to any of the following areas:

• Excellence in Commercial Concrete Construction

• Lean production less waste • Managing natural resources • Minimising energy use • Protecting against pollution • Respect for people • Setting performance targets How Will Entries Be Judged?

Within each Award category entries will be judged by a panel of New Zealand and international industry experts, using an environmental, economic and social sustainability set of criteria.

Extra credit will be given to unique factors and entries that cover more than one facet of sustainability (e.g. both environmental and social sustainability).

Such was the number and diversity of entries in the 2009 Concrete3 Sustainability Award that the 2010 Award winner will be selected from the following categories: • Excellence in Residential Concrete Construction

• Excellence in Civil Concrete Construction • Excellence in Concrete Innovation • Excellence in Concrete for the Community How To Enter & Closing Date For entry information and an entry form visit www. sustainableconcrete.org.nz. You have until Friday 3 September 2010 to submit your entry.

Announcement of Results The winner will be announced at a presentation at the New Zealand Concrete Conference, October 2010. The December 2010 issue of Concrete magazine will include a detailed report on the award, based on the material submitted by the entrants. The winner of the Concrete3 Sustainability Award will be presented with the 2010 Concrete3 Sustainability Award trophy.

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volume 54 issue 2 JUNE/JULY 2010

BUZZ from the Beehive DBH Releases Guidance for Manufacturers of Building Products

buildings fell $802 million (17%) compared with the year ended May 2009.

The Department of Building and Housing (DBH) has released a new guidance document, Using the Product Assurance Framework to Support Building Code Compliance: A Guide for Manufacturers and Suppliers of Building Products.

More information can be found at: www.dbh.govt.nz/building-sector

The guide has been written to advise building product manufacturers and suppliers of the benefits and responsibilities around providing products that are Building Code compliant and therefore fit for purpose within the New Zealand building environment.

The guide can be found at: www.dbh.govt.nz/guidance-information Leaky Homes As part of Budget 2010 the government has made a full and final offer to cover the cost of 25% of leaky home repair bills.

This offer is open if local authorities match the offer and owners drop litigation against the government and local authorities. The government will also guarantee bank loans for the owners of leaky homes to pay for their part of the repairs.

Twenty three local authorities (including Wellington, Christchurch and Auckland - which represent 90% of leaky building claims) have officially declared their support for the package.

DBH Building and Construction Outlook (June Quarter) DBH has published its outlook for the June quarter titled When Will he Building Recovery Pick Up Speed?

DBH offers a cautious outlook for the residential sector, while noting that the non-residential outlook has worsened over the past 6-months with signs the stimulus from publicly funded building is coming to an end. However, despite the “slow and patchy” pace of recovery, construction is expected to rise in 2010.

DBH feel the fundamentals for an upswing in homebuilding are still in place with evidence that property investors had been waiting to see what the May 20 Budget had in store combined with employment levels being expected to improve leading to a continued housing shortage.

The outlook can be found at: www.dbh.govt.nz/building-and-construction-quarterly-report-2

More information can be found at: www.dbh.govt.nz/ws-proposedfinancial-assistance

International

Feedback on Building Act Changes The Government received over 350 submissions on proposed changes to the Building Act following the release of its recent discussion document. The majority of the submissions are supportive of the proposed changes and include a number of technical recommendations.

DBH Work Programme DBH has released its Statement of Intent for 2010 – 2013. This document identifies various building and construction sector priority areas over the medium term, such as ensuring on going confidence and investment, driving down regulatory costs without compromising building quality, and supporting improved productivity.

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The document can be found at: www.dbh.govt.nz/statutoryreports#2010-13

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Building Consents and Work Values

In the year to May 2010 the value of consents for residential buildings rose $416 (8%) while the value for non-residential

For further information contact Pacific Concrete Protection Ltd 09 528 3426 or sales@pcp.co.nz CCANZ-PR03958

The building and construction sector is still struggling to shake off the recession with figures showing 1,333 consents were issued for new housing units (excluding apartments) during May 2010 – a 9.5% drop after seasonal adjustments which followed a 13.5% rise in the previous month.

Global Leaders in Structural Waterproofing www.taminternational.com.au

volume 54 issue 2 JUNE/JULY 2010

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concrete 5

CONCRETE TREASURE bURIED UNDERGROUND tAkiNg AdvANtAgE Of grC’s lightwEight durAbility ANd suitAbility fOr usE with iNtriCAtE mOulds, AuCklANd sCulptOr lOuisE purvis hAs drAwN iNspirAtiON frOm surrOuNdiNg tOpOgrAphy tO CrEAtE A sEriEs Of rEliEf pANEls fOr NEw lyNN’s NEw rAil trENCh. Situated between Portage and Titirangi Roads in the New

After considerable research into potential materials that could be

Lynn town centre, the 8m deep / 860m long rail trench is a key

used for the panels, the Waitakere City Council’s decision to go

component of the Western Line Duplication, itself part of Project

with GRC was based primarily on weight and size considerations

DART, a $600m Government-funded upgrade of Auckland’s rail

for transporting, handling and fixing the panels. The excellent fire

network.

resistance of GRC was also an important factor in its favour. GRC

Asked to submit a design for consideration by Waitakere City Council’s Arts team, which actively pursues the integration of art into the city’s urban development, Purvis’ concept was chosen to adorn both sides of a 200m stretch of the New Lynn rail trench using Glassfibre Reinforced Concrete (GRC).

In designing the panels Purvis sought to convey the importance of the ceramics industry, in particular Crown Lynn Potteries, to the development of New Lynn and the early infrastructure of greater Auckland. The profiles of the panels echo the surrounding landscape, from which the clay that supplied New Lynn’s original brick and pipe manufacturers was sourced, and through which the rail trench is cut.

is a composite material, containing hydraulic cement, silica sand, alkali resistant glass fibres and water. The glass fibres effectively reinforce the mortar mix to enhance its tensile strength, and allow for a thinner and lighter panel.

Interestingly, the panels were attached to the trench wall using stainless steel fixings. This eliminated the need for steel backing sheets or frames, and therefore any potential corrosion issues.

In total, 258 panels, each weighing 400kg and comprised of two sub-panels (one negative and one positive profile), were manufactured using a spray system by GRC New Zealand Ltd from moulds based on Purvis’ foam/fibreglass sculptures (or ‘plugs’). While the manufacture of the panels themselves was relatively straightforward, ensuring GRC New Zealand met Purvis’

The panels’ underlying reference to the fluid New Lynn landscape,

requirements for the correct positive/negative combination and

with its distinctive volcanic ripples, was also very much part of

sub-panel 90o rotation called for careful monitoring.

Purvis’ desire to soften what could potentially have become a cold and unwelcoming locale. “I wanted to make something that was quite organic within a built environment that has lots of straight horizontal and vertical edges.” says Purvis. “I wanted to make the concrete appear more liquid and less hard.”

For Bill Haagh, General Manager of GRC New Zealand Ltd, the New Lynn rail trench has been a rewarding experience on many levels. “Initially posing challenges from a mould perspective, the panels then generated a lot of interest from visiting architects and designers to our yard,” says Bill. “The project also enabled us as a

Although cast from only four basic moulds, each with a positive

local company to create employment, develop the industry’s skill

and negative variation, the panels have been skilfully arranged by

base and make a real contribution to a community project. Then to

Purvis to escape any discernible pattern.

see the panels erected in the trench – that was really exciting stuff.”

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vOLuME 54 ISSuE 2 JuNE/JuLY 2010

As West Auckland’s integrated urban and rail development continues apace it is heartening to see careful construction detailing recognised as important by key decision makers. This is nowhere more evident than in the New Lynn rail trench relief panels, which through the unique properties of GRC will enable

rail commuters to enjoy the work of one of New Zealand’s foremost sculptors while benefiting from more frequent and reliable passenger services.

Louise Purvis. www.louisepurvis.com GRC New Zealand Limited. www.grcnz.co.nz

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concrete 7

WORLD CLASS – GOLDEN bAy CEMENT’S NEW EASTPORT SERvICE CENTRE OPENS IN AUCkLAND thE NEw gOldEN bAy CEmENt AuCklANd sErviCE CENtrE, NAmEd EAstpOrt, wAs OffiCiAlly OpENEd iN fEbruAry by AuCklANd mAyOr jOhN bANks ANd flEtChEr buildiNg iNfrAstruCturE divisiON ChiEf ExECutivE mArk biNNs. “This facility secures Golden Bay Cement’s position in the key Auckland market for at least the next 35 years,” explained Mark Binns at the opening. “We are uniquely positioned to increase our levels of customer service in a market that is going to see a high level of market growth, particularly in the infrastructure sector, out into the future.”

The state-of-the-art facility includes a 25,000 tonne cement bulk store - the largest in New Zealand - and a six-silo service centre.

This new facility has replaced the Golden Bay Cement Hamer Street service centre, making way for the redevelopment of the Tank Farm area by Auckland City.

When visiting the site it quickly becomes apparent that the level of technological sophistication utilised at Eastport is both significant

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vOLuME 54 ISSuE 2 JuNE/JuLY 2010

compared to the facility it has superseded, and unprecedented

by New Zealand standards. Such is the state-of-the-art design of the facility, demonstrated in part by a massive 15 kilometres of installed cabling, that the setting feels almost futuristic.

“We are thrilled with how this big undertaking has come together,” says Petar Misic, who has been the project manager at Eastport for Golden Bay Cement. “It is very satisfying when a project of this size is completed ahead of schedule and on budget with very little disruption. A great deal of credit must go to Fletcher Construction for the way they have delivered the project.”

Fletcher Construction started the groundwork at the 6,000m2 site in mid-June 2008. Structural and civil design was provided by BECA.

The new 25,000 tonne bulk cement store on the northeastern edge of the site has double the storage capacity of the previous site

The new Eastport service centre includes a modern blending plant and distribution facility, including six silos that hold 150 tonnes of cement each.

Three international specialists have provided specific expertise. lbau of Hamburg in Germany designed the specialist cement handling technology. Ammerman and Partners from Australia provided components for the cement handling design and another Australian company, Current Consulting, designed the electrical and control system.

“We cherry-picked the best technology from around the world and worked closely with our design team to satisfy our unique requirements and the planning rules,” adds Petar Misic. “These included meeting height, noise and light restrictions so we blend in to port activities. Health and safety, as well as minimising our impact on the environment, have also been important factors in the overall design.”

The new facility includes two very impressive yet unobtrusive buildings. Gone are the traditional high storage ‘silos’ associated with cement. These have been replaced by the huge 25,000 tonne bulk cement store (measuring 30 metres by 100 metres) on the northeastern edge of the site closest to the waters edge. It has a low profile, horizontal design to minimise disruption of views for those living and working in downtown Auckland. The storage capacity, however, is actually double what Golden Bay Cement had at the Hamer Street site.

The Bulk Store’s structural design is extremely complex with a high density of reinforcing steel in the walls. Built to withstand vast forces in the event of an earthquake, the Bulk Store sits on over 700 piles driven into the bedrock.

The walls are post tensioned to deal with the massive forces.

Approximately 1400 tonnes of steel have been used in the structure along with some 6000m3 of concrete.

From the eastern berth of Bledisloe Wharf Golden Bay Cement’s distribution ship and barge now pump cement into the massive

A Golden Bay Cement truck leaves the distribution facility.

new bulk store. The bulk store is then linked to the service centre where road tankers are loaded. The new Eastport service centre includes a modern blending plant and very efficient distribution facility including six silos that hold 150 tonnes of cement each.

Two silos feed each of the three service lanes, which load cement tankers. So three cement tankers can be filled at one time and can be loaded in just 10 to 15 minutes.

“This is the first plant in New Zealand to include continuous automated blending,” explains Petar Misic. “This opens up a whole new range of opportunities for us to blend specialist cements for our customers.”

Article reproduced with kind permission from Golden Bay Cement.

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Holcim Trucks Afloat for Lake Project Lake Karapiro, on the Waikato River, 30 kilometres from Hamilton, is the venue for the 2010 World Rowing Championships. It is also the site where two power pylons, bedded eight metres below the surface of the lake have been the focus of a maintenance project involving Holcim (New Zealand) Ltd. The 220kV line that crosses Lake Karapiro forms part of the national electricity grid. Constructed in 1944, the line pre-dates the creation of the lake to power the Karapiro Power Station in 1947. The pylons were bedded in hand-mixed concrete and the foundations have been underwater for over 60 years.

A recent survey discovered that some concrete had worn away from the foundations. Maintenance was scheduled for this year, with a requirement to be finished in May, to allow preparations for the rowing championships in October.

A concrete pump is required to pour concrete underwater.

Concrete was pumped through a hose to the bottom. The end of the hose was kept immersed in the freshly poured concrete to avoid contamination by keeping water out and minimising turbulence. Important to the success of the pour was ensuring continuous placement.

Work by the team at Holcim’s Cambridge plant was a major determinant of success for the operation. Getting concrete to set underwater is not only counter-intuitive, it is also technically

With a project start date of 1 March, the project contractors faced unusual technical and safety challenges while working to a tight timeframe.

challenging. Holcim Batcher Steve Harding and Tester Linley

According to Dennis Tickelpenny, Key Account Manager - Waikato for Holcim Concrete & Aggregates, “This was a project notable for rigorous health and safety and environmental measures.”

The concrete mix produced by the batching plant for this pour was

Pouring concrete in the middle of the lake required Holcim trucks to get out there. An 80 tonne barge, towed by a tug, carried the 20 tonne truck for the voyage. Holcim drivers wore life vests and full health and safety gear during the operation, travelling out on the safety of the tug rather than on the barge.

Wallace were responsible for ensuring the Tremie mix used on the project complied with the accepted mix design.

free-flowing. The concrete was retarded for four hours through the use of Sika admixtures. Quality was closely monitored, with slump tests conducted at the Cambridge plant on each load to attain a target of 180mm slump.

Each day of the pour, a set of three cylinders were taken from the batch. One cylinder was crushed and tested for strength after seven days. The remaining two cylinders were for testing at 28 days.

Once anchored at the pylon a Hiab on the barge lowered the hose to the lake bottom. Divers, wearing helmets with built-in radio communications, guided the concrete pump hose in the demanding low visibility conditions.

At the preparation stage, after the deteriorating concrete around

“Visibility for the divers on the bottom was just one metre,” said Dennis.

the two 45m tall pylons.

Each pylon was screened off to avoid contamination of the lake water from the concrete mix. The large screens were attached to floats, encircled the pylons and were anchored to the bottom.

Karapiro will be available for the October World Rowing

A view of the barging operation in progress on Lake Karapiro. Getting the fully-laden 20 tonne Holcim truck to the middle of the lake was a carefully managed process.

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volume 54 issue 2 JUNE/JULY 2010

the legs was cleaned up, the divers of Bay Underwater Services installed steel casing and steel cross-bracing. A total of 337m3 of concrete was required to fill the casings around the eight legs of

The job was finished for Holcim by 1 May, ensuring that Lake Championships.

Article reproduced with kind permission from Holcim (New Zealand) Limited.

THE TIME HAS ARRIvED FOR CONCRETE ROADS Tim Almany, American Concrete Paving Association and Tom Evans, Maryland Ready Mix Concrete Association

CONCrEtE fOr mArylANd, A grAssrOOts OrgANisAtiON fOrmEd tO COmmuNiCAtE thE ECONOmiC ANd ENvirONmENtAl bENEfits Of CONCrEtE pAviNg iN thE stAtE, hOpEs tO gAiN AN EquitAblE shArE Of mArylANd’s NEw rOAd CONstruCtiON fOr CONCrEtE. At thE vEry lEAst, thE OrgANisAtiON wANts thE OppOrtuNity fOr its iNdustry tO bid ON EvEry pAviNg jOb iN mArylANd.

Founding members are Chaney Enterprises, a family-owned and operated concrete manufacturer located in Southern Maryland; the American Concrete Paving Association (ACPA), Mid-Atlantic chapter; and the Maryland Ready Mix Concrete Association. bREAkiNG ThE cUlTURAl MOUlD This newly formed coalition has a daunting task ahead. Despite all the benefits of using concrete, there is only a 2.5% market share.

This statistic is repeated at the national level with asphalt enjoying a 94% market share.

Engineering specifications for new construction and resurfacing projects typically call for asphalt, eluding the potential cost savings for state taxpayers.

But with asphalt’s rising costs, technological advances in concrete engineering and the nationwide urgency to protect the environment, Concrete for Maryland believes the time has come to turn those numbers around.

The ACPA is very excited about being a member of the coalition to raise the awareness of concrete pavement applications in Maryland. It is delighted to work with the concrete industry and hopes that its collaborative efforts can result in more concrete pavements for the state. cARE FOR AN AiliNG ENViRONMENT In 2005, the Green Highways Initiative was launched by the uS Environmental Protection Agency. This initiative was developed as a means to co-ordinate

can demand that the elected leadership convey the changes needed to include concrete to engineering specifications for new construction and resurfacing projects.

The environmental advantages are clear.

Concrete offers Maryland residents reduced heat islands, more brightly lit roads, better fuel efficiency and durability that will have environmental and economic benefits for generations.

As the coalition’s visibility increases, new members will be needed to keep the organisation robust and to ensure awareness over the entire state.

Yet today, Maryland’s planners and developers are still unaware of the environmental upside to concrete paving. In fact since 2005 concrete paving has decreased, while asphalt paving has increased. This trend is going the wrong way toward the greater good of the environment and Maryland’s citizens.

Concrete for Maryland members have been working one-on-one with municipal leaders, state highway officials and environmental groups to educate these stakeholders on the green aspects of concrete. With the individual forces joining together, today’s social climate of environmental stewardship provides another opportunity for Concrete for Maryland to advocate the benefits of concrete.

SPREADiNG ThE cONcRETE MESSAGE Awareness and discussion are key. Armed with information and taking a viral approach to information sharing, Concrete for Maryland wants to reach the broadest network, from decision makers to average citizens by hitting Facebook, Twitter, the internet, trade shows and conferences.

The organisation believes that once the public is educated on concrete’s environmental advantages and potential cost savings, they

New software is available to engineers and specifiers that compares asphalt and concrete costs for any specific project, including life-cycle maintenance costs. The comparison is surprising for those who have assumed asphalt is the only affordable paving option available.

Additionally, the long-term cost savings potential is more apparent from this year’s harsh winters and the resulting pothole repairs facing public works offices.

In the short time since Concrete for Maryland has been launched, a few state legislators are beginning to take notice and are interested in information. When concrete paving costs can be compared to asphalt, the key decision makers can see concrete translate into lower costs for taxpayers, a reduction in road construction delays and the lost time and money sitting in traffic.

FURThER iNFORMATiON: For more information visit: www.concreteformaryland.com.

Article reproduced with kind permission from American Concrete Paving Association, Maryland Ready Mix Concrete Association, and the UK Concrete Society.

2.70%

$600

2.65%

$500

2.60%

$400

2.55%

$300

2.50%

$200

2.45%

$100 $0

2.40%

2000

2001

2002

2003

2004

2005

2006

2007

2008

State Highway Administration price for Asphalt

Founded by a coalition of trade organisations and companies in the ready-mixed concrete industry, Concrete for Maryland is an information clearing house and resource aimed at promoting the benefits of using concrete instead of asphalt for road projects in the state.

environmental practices and transportation to build and sustain roads in an environmentally responsible way, including design, construction and maintenance.

Percentage of Concrete Roads

We’re facing a big challenge in changing perceptions and changing a culture that for so long has favoured asphalt over concrete, but we believe the timing is right and our message of environmental responsibility and cost-savings will resonate with those who can make a difference for Maryland’s taxpayers and motorists.

[Figure 1]: Concrete road market share in Maryland versus price of asphalt. vOLuME 54 ISSuE 2 JuNE/JuLY 2010

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concrete 11

Don’t Get Burnt Preserve Life & Minimise Damage with Concrete

In the design, construction and occupancy

CONCRETE’S FIRE RESISTANCE

of residential and commercial buildings, as

First and foremost, concrete does not burn – it cannot be ‘set on fire’. Unlike alternative building materials concrete also does not produce toxic smoke or fumes in a fire, or drip harmful molten particles. Concrete is virtually non-combustible, and does not contribute to the fire load. Concrete’s excellent fire resistance can be attributed to its main constituent materials (cement and aggregate), which combine to produce a material (concrete) that has low thermal conductivity.

well as civil structures such as tunnels, it is crucial to minimise the risks associated with a possible fire event.

Regardless of cause, once a fire has become established in a building it can spread rapidly, endangering life and destroying property through a combination of hazardous smoke and gases, flames and extremely high temperatures. Both as a material, and in engineered structures, concrete’s range of fire resistanT properties ensure that it performs well in a fire event, helping to preserve life and minimise damage.

This low thermal conductivity (rate of heat transfer) enables concrete, even after prolonged periods of exposure to fire, to maintain a relatively low internal temperature. This in turn enables concrete to retain structural and heat shielding capacity, as well as prevent fire spread, allowing occupants to evacuate the building or for fire service personnel to conduct operations more safely.

While surface concrete may become loose at high temperatures, a phenomenon known as spalling, it can be minimised through the use of polypropylene fibres in the concrete mix.

Although the engineering justification for sprinkler system technology cannot be questioned, it must be considered at a building’s design stage that most reservoirs in New Zealand are fitted with seismic auto-shut valves in order to retain water supply.

In a post-earthquake fire event sprinkler systems may therefore not be fed with an adequate water supply.

This possibility, coupled with the likelihood that fire service personnel will be delayed following a major earthquake, suggests that those buildings constructed using inherently fire resistant materials such as concrete will offer superior performance.

In the majority of cases, concrete’s inherent fire resistance means that unlike other building materials it generally does not require additional fire protection measures in the form of linings or paint, the cost benefit of which can be considerable.

The economic advantages of concrete’s fire resistance also become clearly apparent post fire event. As the majority of

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volume 54 issue 2 JUNE/JULY 2010

concrete buildings are not destroyed during a fire, and their load bearing capacity is largely preserved, they can be repaired and reoccupied in a relatively short space of time. Such speed and convenience helps reduced the financial impact following a fire, and is preferable to demolition and replacement.

TOTAL FIRE ENGINEERING The fire resistant properties of concrete must be seen as a single element within an overall fire engineering approach to building design. This approach considers both passive measures, such as fire resisting walls and floors, and active measures, such as fire alarms, smoke detectors, sprinkler systems and automatic smoke vents. As an over-reliance on active measures is not desirable, concrete’s passive contribution to safety within a holistic fire engineering approach can be significant.

SUMMARY It is imperative that buildings and structures are created to protect people and property from numerous threats – including fire.

Legislation and design codes exist to help achieve this aim, and are updated to reflect international research and development in concrete’s fire safety.

As a non-combustible material concrete rarely requires additional fire protection, while during a fire event it does not add to the fire load or produce harmful emissions.

Concrete’s slow rate of heat transfer means that within structures it prevents fire spread, while providing protection to evacuees and fire fighters. Following a fire concrete structures generally remain intact, allowing for relatively quick repair and reoccupation, saving time and money.

FEATURES OF CONCRETE Does not drip molten particles

•

Does not produce toxic smoke or fumes

•

Does not require additional fire-protection

•

Minimises fire (and water) damage

•

Non-combustible - does not contribute to fire load

•

Provides fire shield, prevents fire spread

•

Retains structural strength in typical fire event

•

REFERENCES • Concrete Centre (2004). Concrete and fire: Using concrete to achieve safe, efficient buildings and structures. Surrey, UK. • Concrete Society (2008). Assessment, design and repair of fire damaged concrete structures. Technical Report 68. Surrey, UK. • European Concrete Platform (2007). Comprehensive fire protection and safety with concrete. Brussels, Belgium.

Images left to right: Fotosearch, Matt Cashmore UK, Jupiter Images, Ralf Kessel.

This range of properties ensures concrete provides an impressive level of fire resistance that ultimately assists to preserve life and minimise damage.

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concrete 13

At Work with Firth Industries Firth Industries continues to provide innovative concrete solutions to technical and logistical challenges on key construction projects across the country. This is no more evident than their work on Nga Awa Purua, New Zealand’s newest geothermal power station, and the No. 1 Featherston Street Development in Wellington, New Zealand’s largest commercial office complex.

Firth recently fulfilled its contract to deliver 13,000m3 of concrete to the $430 million, 140MW, Nga Awa Purua Geothermal Power Station, north east of Taupo. A joint venture between Mighty River Power and the Tauhara North No. 2 Trust, the now fully operational power station can supply sufficient electricity to power 130,000 homes – the equivalent of every home in Hamilton, Tauranga, Rotorua and Taupo.

Since the project began in 2007, Firth has provided concrete under contract to Hawkins Infrastructure. Plant Supervisor for Firth Taupo and Tokoroa, Tony Hurunui says, “Firth was delighted to be awarded the contract and it has been a major project for the team in our region.”

“Most of the concrete has come from Firth’s Taupo plant, however for the larger pours we’ve also sourced some from the Tokoroa plant. Trucks from Whakatane, Rotorua and even as far south as Hawkes Bay have also been commandeered to help with the job,” says Mr Hurunui.

Firth’s team developed a special high strength 40 MPA mix, which contained fly ash to enhance durability and help reduce the heat of hydration.

Following extensive testing this high strength concrete was used in many parts of the power station including the cooling tower, the pipelines and the underground piles.

“Big holes were drilled into the ground and filled with concrete to stabilise the foundations of the plant, as there can be a lot of earth movement around Taupo due to the large amount of light weight pumice present,” says Mr Hurunui.

“The main challenges we faced were in quality control and working to keep a high degree of consistency in our mixes. There were some hold ups early on in the project due to weather and issues in drilling for the piles, but these were soon overcome,” he says. “The finished plant is very impressive and will benefit New Zealanders for generations to come.”

Project Manager for Hawkins Infrastructure, Glenn Kaukau says, “We’ve had a great working relationship with Firth. With a project this large there are always numerous issues and the Firth team has been able to answer all the questions we’ve had and then follow up swiftly with practical solutions.”

The Nga Awa Purua Project Manager for Mighty River Power, Paul Ware says, “Firth’s large pours, and even the small ones, seem to have gone without incident. With so many subcontractors it’s good to have a competent contractor on site who knows their business inside out as it removes worries and concerns.”

Meanwhile in Wellington, Firth is close to completing a contract it began in January 2008 to supply concrete for the largest commercial office building in the country.

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Located on the corner of Featherston and Bunny Streets, the new building has a massive floor plate of 3,200m² and is set to be occupied by the Inland Revenue Department (IRD). Being built by Fletcher Construction, the building consists of retail and service spaces on the ground level, two levels of car parks and twelve levels of office space.

Firth’s Wellington Area Manager, Cameron Lee says, “The concrete structure has about 14,000m3 of concrete in total, with the piling and footings accounting for some 3,000 m3 alone.

Some of the piles had to be drilled up to 42 metres deep as the area sits across the road from the harbour front and is all reclaimed land.”

The greatest challenge for Firth was to design a concrete mix that could be pumped up as high as 16 floors. “In order for the concrete to be pumpable we had to come up with a high strength workable mix, that was cohesive,” says Mr Lee, “This particular mix has extra sand and cement as well as more super plasticizer than a normal mix.”

Firth also had to create a special concrete mix for the shear walls in the lower floors of the building, which contained a large amount of fly-ash to reduce the heat of hydration, an issue constantly monitored by Firth throughout construction.

The initial pour for the foundations was the largest the placing team had to deliver. In just under seven hours 1100m3 of concrete supplied by 38 trucks was placed. Firth was able to deliver such a large quantity in such a short time by utilising trucks from Firth plants all around the lower North Island. The success of the concrete aspects of such a large scale project can be attributed to precise planning, a strong professional relationship between Firth and Fletcher Construction, not to mention a dedicated and focused team.

The scale of the new building has in no way compromised the overriding commitment to green building practices.

Concrete’s unquestionable durability, along with the energy savings afforded through its thermal mass, account for much of the building’s green credentials, and have contributed to Fletcher Construction securing a five star rating for the building from the New Zealand Green Building Council.

The project is expected to be completed around September 2010, with IRD staff scheduled to occupy their new offices at the end of the year.

Top images: No.1 Featherston Street, Wellington Bottom images: Nga Awa Purua Geothermal Power Station

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concrete 15

Sophisticated Concrete for Family Living Despite hints of a backlash against the ‘grey box’, the popularity of fair-faced concrete homes remains steady throughout Europe. This is stunningly apparent in Philipp Wieting’s complex and unique design for a light-flooded yet private family residence in the Swiss town of Chur.

Situated on a steep hillside plot and encircled by a busy road, the street frontage of the home has a north-south orientation, which leads to a secluded inner courtyard. The courtyard has been achieved through off-centred layering of the three floors and the subtle use of a concrete wall on one side of the house and an integrated auxiliary building on the other to create protective arms.

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The entire house is constructed from in-situ concrete, and makes restrained use of contrasting surface finishes to provide depth and texture. While rough horizontal plank formwork has left its imprint on the top floor and basement facades, the smoother finish of the ground floor façade was created through the use of a large upright formwork frame. The positioning of discreet windows contributes to the overall sculptural effect, with the small grey-colour framed top floor windows set as inconspicuously flush as possible.

The almost 300m2 of floor space has allowed for a generous sized gallery that connects the ground floor with the top floor, while also offering a picturesque view of the landscaped garden and surrounding mountains. Dappled light fills the dining area by way of an elevated window. The narrow, windowless corridor and stairwell on the ground floor also offers an extraordinary experience, heightened by its contrast with the bright and open adjacent kitchen and living areas.

Hints of the ‘grey box’? Perhaps, but with sufficient idiosyncratic features to create a distinctive residence that showcases not only the talents of the architect, but also the vast range of properties offered to residential construction by concrete.

Article reproduced with kind permission from opus C – Concrete Architecture & Design (www.opusC.com) All images cortesy of Werknetzarchitektur

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concrete 17

FROM THE ARCHIvES 1967 – A yEAr Of CElEbrAtiON ANd uNCErtAiNty In May 1967 Concrete magazine, then NZ Concrete Construction – Journal of the New Zealand Portland Cement Association, celebrated its 10th anniversary and 108th issue. At that time M.A. Craven was the Association’s general manager, the engineering staff was comprised of B.J. Kemp, R.J. Christie and G.S.A. Hamilton, and M.D. Price was the publications and information officer. Member companies were Wilsons (NZ) Portland Cement, Golden Bay Cement Co, NZ Cement Holdings, Guardian Cement Co, and Waitomo Portland Cement.

Topics of concern in the anniversary issue were sands for mortars and plasters, exposed aggregate finishes, chalking bolt holes, and the new Dunning and Son Ltd concrete tile factory in Oakengates (uK), while the recently published NZSS 2086:1967 Ready Mixed Concrete Production unsurprisingly received an extremely positive ‘book’ review.

The cover featured an under construction 14-storey Securities House, 126 The Terrace, Wellington, which was designed by Biggs, Power, and Clark, architects and engineers, and constructed by P. Graham and Son Ltd. Considering its placement on the cover of such a milestone issue, it was perhaps not coincidental that Securities House became the home of the New Zealand Portland Cement Association in 1968.

Of equal interest to the May issue’s anniversary significance is the editorial column that appeared a mere seven-months later in the November issue. Entitled 1967 – A Year of Uncertainty, the column begins by praising the New Zealand construction industry for its “considerable achievements”, only to then lament that the current calendar year had been “a period of alarm calling for re-examination and reassessment.”

The column’s concerns about reduced construction industry turnover echo today’s anxiety over the current recessionary environment, while its proposed solution of “greater efficiency” through reduced importation of building materials, increased technology adoption, and enhanced operational research, also sounds familiar.

Left: The building as it appears today – now the Terrace Tower Apartments.

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vOLuME 54 ISSuE 2 JuNE/JuLY 2010

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HOW COOL IS THAT? THE ALbEDO EFFECT AwArENEss Of CONCrEtE’s AlbEdO EffECt hAs uNtil rECENtly rECEivEd littlE AttENtiON, dEspitE its pOtENtiAl tO rEduCE glObAl wArmiNg. whAT iS AlbEDO? Albedo, or solar reflectance, is the ratio of reflected solar radiation to the total amount that falls on that surface. The albedo of a surface is measured from 0, where no incoming radiation is reflected (total absorption), up to 1, where all the incoming radiation is reflected.

Although the effects of weathering and age may influence the albedo of particular surfaces, light surfaces generally have a higher solar reflectance than dark surfaces, and therefore a higher albedo.

For fresh snow the albedo is 0.9, whereas for dark soil or asphalt it falls in the range of 0.05 to 0.2. For concrete made with ordinary Portland cement the albedo varies between 0.2 and 0.4, although this can be increased with the use of some SCMs or white cement. whY iS AlbEDO iMPORTANT? When solar radiation is absorbed by a material’s surface it raises that material’s temperature, and is re-emitted as infrared radiation (or heat), whereas most of the solar radiation reflected from a material’s surface passes out into space. Therefore, the lighter a material’s surface colour the more solar radiation it will reflect, resulting in less heat and in turn less global warming – see figure 1.

In this respect, the selection of concrete over alternative dark materials in paving, road and roofing applications gains immense importance. Armed with an awareness of how to maximise the albedo effect in the built environment, designers and their clients can help reduce heat generation, and account for that reduction as an equivalent CO2 saving that helps reduce global warming.

The significance of concrete’s albedo is clearly demonstrated by researchers at Laurence Berkley National Laboratory, who estimate that cool surfaces (roof tops and pavements, along with shade trees) could reduce the annual uSA energy bill by some uS$50 billion.

Furthermore, lighter and more reflective surfaces, particularly for roading and car parks, enhance night-time visibility and reduce lighting requirements, saving money and energy, as well as improving safety.

SUMMARY With an enhanced understanding of the albedo effect, construction professionals can now make use of concrete’s high solar reflectance to not only reduce lighting and cooling energy requirements, but also deliver significant equivalent CO2 emissions savings that assist to slow global warming.

REFERENcES Akbari, Hashem. (2008). Global cooling: Increasing world-wide urban albedos to offset CO2. Fifth Annual California Climate Change Conference, Sacramento, CA. Portland Cement Association. Green in Practice 103 - Cool Communities.

Concrete Thinking. http://www.concretethinker.com/technicalbrief/coolcommunities.aspx Seymour, P., O’Flynn, D., & O’Connor, C. (2009). GGBS and reducing global warming: The albedo effect. World Cement. 40 (12), p 46-52.

Another factor that demonstrates the potential importance of concrete’s albedo is that continued urbanisation has led to the adverse impact of Heat islands, where the air temperature has grown significantly higher than the surrounding rural environment.

This has created a huge call for air conditioning during summer, which increases energy demands and associated CO2 emissions.

The Albedo Effect A t m o s p h e r e Solar radiation passes through the clear atmosphere

Some solar radiation is reflected by the atmosphere

Most solar radiation reflected from lighter coloured surfaces passes out into space

GREE

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Seals cracks and cavities in dry or wet situations

S

Seals where there is pressurised water Restores structural integrity Infrared radiation is absorbed and re-emitted by the greenhouse gas molecules.

The direct effect of this is warming of earth’s lower atmosphere and surface

Darker Coloured Surfaces: most solar radiation absorbed and re-emitted as infrared radiation

Lighter Coloured Surfaces: most solar radiation reflected out into space

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Some of the infrared radiation passes through the atmosphere and is lost in space

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Figure 1. How solar radiation is reflected, absorbed and re-emitted as infrared radiation. vOLuME 54 ISSuE 2 JuNE/JuLY 2010

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concrete 19

Mood Lighting with a Hard Edge In partnership with niche retailer Decode, who seek to showcase the creative talents of London’s young designers, Benjamin Hubert has adopted a material focused approach to push the potential of concrete as an industrial material and also challenge awareness of its value.

After graduating from Loughborough University in the UK at the end of 2006, Hubert established his own self-titled design studio, which he launched with great success at the 100% Design expo in 2007.

From that point on Hubert’s design studio has grown in stature, focusing on a material and process approach that has received a range of prestigious international industry awards and press coverage. This culminated with Hubert being short listed for best new exhibitor and profiled as a ‘name to watch in 2008’ by The Telegraph.

Hubert now works with a number of manufacturers and stockists, producing a range of interior products from furniture to ceramics, using an eclectic range of materials and processes.

Hubert’s most notable triumph to date has been the success of his concrete Heavy Lights, which are the culmination of both innovative manufacture and visual simplicity. The heavy suspension series is comprised of a hand-cast concrete shade in a natural white, light grey or dark grey finish. Fittings are either in red braided cable with brushed steel ceiling rose or white braided cable with white ceiling rose. They range in size from 130mm high / 120mm diameter, to 235mm high / 288mm diameter, and in weight from 3.5 to 7.5kg Hubert recently progressed from the heavy suspension series to the heavy desk lamp, which is a hand-cast concrete shade and base, available in a natural white, light grey or dark grey finish, with arm in either walnut or oak veneer, and a red braided cable and steel fittings.

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volume 54 issue 2 JUNE/JULY 2010

The heavy desk lamp has received much attention within the design media, as well as winning the 2009 British Design Award with Elle Decoration.

Hubert’s designs may recall trends of previous decades, but they retain enough originality in perspective and material to achieve their practical objective as well as convey creative integrity.

DEcODE – www.DEcODElONDON.cOM bENJAMiN hUbERT – www.bENJAMiNhUbERT.cO.Uk

In circulation since 1957, Concrete is the quarterly information source that provides solutions and inspiration for a wide cross-section of building professionals.

cast your advertisements in Concrete

Architects, engineers, builders and those in the concrete sector turn to Concrete for practical, technical and design information on how to maximise the potential of the world’s most widely used construction material.

To reach the key decision makers within the building and construction industry consider the cost competitive opportunities offered through advertising in Concrete.

for further information please contact: Adam leach p +64 4 915 0383 E adam@ccanz.org.nz w www.ccanz.org.nz/ ratecard.pdf

vOLuME 54 ISSuE 2 JuNE/JuLY 2010

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concrete 21

CCANZ Library

The Sustainable Concrete Guide

by U.S. Green Concrete Council

Listed below is a small selection of recently

than others. Even with the best slab designs and proper construction, the Guide explains that it is unrealistic to expect crack-free and curl-free floors.

New Zealand Architecture Awards 2010 by Balasoglou Books

acquired material by the CCANZ library. To borrow one of these titles, simply email library@ccanz.org.nz The library catalogue can be accessed electronically via www.ccanzlibrary.org.nz Management for the New Zealand Construction Industry

by Suzanne Wilkinson and Rosemary Scofield For the owner and project design/ construction team, this comprehensive Guide can be a resource to understand and quantify concrete’s potential contribution to sustainable development.

Its practical strategies, examples, and references provide the link between sound sustainable ideas when using concrete and the need for numerical verification and implementation.

While authored with a focus on U.S. projects, this Guide has already garnered international interest in filling gaps in the dissemination of information on concrete and sustainability. It is the first in a series of guides on sustainable concrete published by the U. S. Green Concrete Council.

This 2nd edition provides an overview of the basics of management for students in construction and construction-related disciplines, in particular construction management, quantity surveying, civil engineering, property, planning and architecture. It will also be useful to people working in management in the New Zealand construction industry such as engineers, quantity surveyors, project managers and architects.

The book discusses the project, legal and business challenges that managers face with a focus on the way the New Zealand construction industry operates – in terms of general management principles and their practical application.

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360R-10 Guide to Design of Slabs-on-Ground by American Concrete Institute This Guide presents information on the design of slabs-on-ground, including design theories, types of slabs, soil-support systems, loadings, and jointing. Design methods are given for unreinforced concrete, reinforced concrete, shrinkage-compensating concrete, post-tensioned concrete, fibrereinforced concrete slabs-on-ground, and slabs-on-ground in refrigerated buildings, followed by information on shrinkage and curling.

Advantages and disadvantages of these slab design methods are provided, including the ability of some slab designs to minimize cracking and curling more

This full colour guide to the New Zealand Architecture Awards, published

by Balasoglou Books (j.balasoglou@ xtra.co.nz), is more comprehensive and detailed than ever to reflect the increased number of categories and shortlisted entries. The entries encompass a comprehensive range of building types, and all make a unique and valuable contribution to New Zealand’s built environment. Highlights from this year’s Awards include Ironbank (RTA Studios) and the NZI Centre (Jasmax), with John Scott’s Our Lady of Lourdes in Havelock North taking out the Enduring Architecture Award.

Library Quiz To go in the draw to win a copy of Management for the New Zealand Construction Industry by Suzanne Wilkinson and Rosemary Scofield answer the following simple question: Which renowned structural engineer was recently made an Officer of the New Zealand Order of Merit?

Email your answer to library@ccanz.org.nz.

Entries close Friday 27 August 2010.

Congratulations to Stephen Palmer of Stephen Palmer Design Studio, who correctly answered the March 2010 Library Quiz to receive a free copy of BIG IDEAS: 100 Wonders of New Zealand Engineering by Matthew Wright.

CONTACTS New Zealand Ready Mixed Concrete Association Ph (04) 499 0041 Fax (04) 499 7760 Executive Officer: Rob Gaimster President: Jon Hambling www.nzrmca.org.nz

New Zealand Concrete Masonry Association Ph (04) 499 8820 Fax (04) 499 7760 Executive Officer: David Barnard President: David Aitken www.nzcma.org.nz

Precast NZ Inc. Ph (09) 638 9416 Fax (09) 638 9407 Email: ross.cato_precastnz@xtra.co.nz Executive Officer: Ross Cato President: John Marshall www.precastnz.org.nz

New Zealand Concrete Society Ph (09) 536 5410 Fax (09) 536 5442 Email: concrete@bluepacificevents.com Secretary/Manager: Allan Bluett President: Dene Cook www.concretesociety.org.nz

New Zealand Master Concrete Placers Association Ph (06) 873 4428 Fax (06) 873 4429 Email: office@mcpa.org.nz Business Manager: Carol McMillan www.mcpa.org.nz

News from the Associations New Zealand Concrete Society (NZCS) SA-2009 Subcontract Seminars July 2010 The Master Builders subcontract agreement SC1 has been the standard building subcontract for many years. However, a working group comprising representatives of the Registered Master Builders Federation and the Specialist Trade Contractors Federation was formed to develop a new standard form of subcontract. The group included senior staff from Hawkins Construction, Fletcher Construction, Mainzeal Construction and Foster Construction as well as representatives from Electrical, Precast, Reinforcing and Roofing Subcontracting Industries.

The resulting document Subcontract Agreement SA-2009 received Ministerial endorsement in November 2009, and has now been published. The Master Builders have withdrawn SC1 in favour of SA-2009. The new 34 page document is simple and easy to use, but like any new legal document, it needs to be understood to be used properly. It should benefit all subcontracting industry participants, by reducing administration costs, reducing disputes, and improving relationships.

This seminar will give participants an understanding of the document and they will leave knowing how to use it properly and obtain the full advantage available from it.

Seminar Dates • Christchurch – 26 July 2010 • Wellington – 27 July 2010 • Auckland – 29 July 2010 For more information on how to register email concrete@bluepacificevents.com.

STANDARD PRE-CAST CONCRETE BRIDGE BEAMS SEMINARS New Zealand Transport Agency (NZTA) Research Report 364 Standard Pre-cast Concrete Bridge Beams was published in December 2008. The report presented a range of standard bridge beam designs to replace those developed in the 1970’s by the former Ministry of Works, which have dated in respect of international best practice and New Zealand design standards. These new standard precast bridge beam designs were the culmination of five years of research, consultation and design carried out by a team comprising Beca, Opus and Precast New Zealand. The project was jointly sponsored by NZTA and CCANZ. The one day seminars will explain the design assumptions, adopted design approaches and application of Research Report 364, as well as cover the rationale for selecting current Bridge Beam shapes and their use in the efficient design of road bridges. These seminars will also help attendees to understand the application of these standard designs and will boost the confidence of designers and manufactures with regard to the application of Research Report 364.

Seminar Dates • Wellington – 16 August 2010 • Christchurch – 17 August 2010 • Auckland – 19 August 2010 For more information on how to register email concrete@bluepacificevents.com.

High-Calibre Information at PRESSS Seminars There was a strong consensus amongst industry professionals who attended the PRESSS technology seminar series held early this year that they received exceptional information on a state-of-the-art technique.

NZCS Council Member Paul Wymer, who helped coordinate the seminars, says feedback from the 125 attendees was extremely positive. Paul also acknowledged the presenters - Stefano Pampanin (University of Canterbury), Alistair Cattanach (Dunning Thornton Consultants) and Gary Haverland (Structex Metro), saying that “Their design knowledge, technical insights and local experience were extremely valuable to those in attendance.”

The PRESSS Design Handbook is still available for sale at a cost of $250 plus GST. Order forms are on the Concrete Society’s website – www.concretesociety.org.nz The PRESSS Design Handbook, developed by the NZCS and Precast NZ Inc, includes worked examples and would be a useful addition to any collection of technical publications.

The NZCS thanks the principal sponsor Precast NZ Inc, and the supporting sponsors BBR Contech and Stahlton Engineered Concrete.

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concrete 23

BEWARE. SOME SYNTHETIC FIBRE SUPPLIERS ARE

STRETCHING

THE FACTS. www.bosfa.com

Steel and Synthetic fibres?!

Macro synthetic fibres become effective at crack widths that are wider in comparison to steel fibres at the same volume fraction and it is well documented that they creep under sustained load / stress.

BOSFA supply a range of steel and synthetic fibres to markets throughout Australasia. However, at this stage we are very careful not to market macro synthetic fibres into structural applications (where post crack strengths are used in design) and where tight crack control is required, such as ground supported slabs. Applications that are well suited for macro synthetics would be where crack control, fire and long term performance aren’t a design consideration, such as temporary shotcrete linings in mines.

We currently recommend steel fibres for applications such as permanent tunnel linings, pre-cast elements, slab on grade etc, all of which have generic and comprehensive design rules developed specifically for steel fibre reinforced concrete.

REALISE GREATER EnGInEERInG EFFICIEnCY WITHOUT COMPROMISInG QUALITY On YOUR nEXT PROJECT. TALk TO THE LEADER IN FIBRE REINFORCED CONCRETE ENGINEERING CALL 1300 665 755 (AUS), 0800 665 755 (nZ) OR vISIT BOSFA.COM

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It’s our view that until the effects of creep are fully understood and specific design rules for macro synthetic are developed, concrete companies, engineers and contractors alike should treat their use in the general applications mentioned above with caution.