MEMBER, ANDINTERNATIONAL,CONTRIBUTOR,APPRENTICEPLANTAWARDS SCM CONCRETE RESEARCH SERIES CONCLUDES WITH DURABILITYVOLUMEPERFORMANCE61ISSUE4 concrete
UPFRONT concrete MAGAZINE AdamEditor/Advertising:Leach +64 4 915 adam@concretenz.org.nz0383 AngeliqueSubscriptions:Van Schaik +64 4 499 admin@concretenz.org.nz8820 concrete is published quarterly by Concrete NZ PO Box 448 Level 4, 70 The Terrace ©advertisements.ofresponsibilityprojects.ofaremagazineWhileareDisclaimer:ISSN:ISSN:Website:Email:Tel:NEWWellingtonZEALAND+6444998820admin@concretenz.org.nzwww.concretenz.org.nz1174-85401174-9374(online)TheviewsexpressedinconcretenotnecessarilythoseoftheConcreteNZ.theinformationcontainedintheisprintedingoodfaith,itscontentsnotintendedtoreplacetheservicesprofessionalconsultantsonparticularTheAssociationacceptsnolegalofanykindforthecorrectnessthecontentsofthismagazine,includingCopyright2022ConcreteNZAdvertorial Cover image: Maidstone Max - Tō Tātou Papa Tākaro. Upper Hutt City Council. THE MAGAZINE OF CONCRETE NZ Industry associations wear many hats, traditionally emphasising the sharing of best practice and the development of technical Standards. Increasingly however, their role in helping members better understand external issues and contribute their experiences in support of effective lobbying and favourable policy outcomes, has become equally as important. As illustrated by the examples below, this applies to Concrete NZ, which is escalating its advocacy efforts across multiple policy, business and sustainability topics, including climate change.
BUILDING FOR CLIMATE CHANGE - NEW BUILDINGS EMBODIED CARBON ASSESSMENT
Following industry feedback, including from Concrete NZ, the Ministry of Business, Innovation and Employment’s (MBIE) Building for Climate Change team has developed a proposed methodology for assessing the embodied carbon of new buildings in New Zealand. Concrete NZ’s call for a broader scope that embraces full Lifecycle Assessment and includes a building’s fit-out (e.g. carpet) as well as concrete’s CO2 recarbonation capability has been heeded, along with the need for timber’s biogenic carbon to be reported separately.
The resulting updated R-values for the different building elements in the Building Code Clause H1 Energy Efficiency target a 40 percent reduction in the energy needed to heat and cool residential homes, and 23 percent for large buildings, compared to previous minimum status quo requirements. Concrete NZ lobbied for the increased R-values to strike a pragmatic balance between reducing emissions from constructing and operating buildings, with cost and material supply considerations.
GOVERNMENT RELATIONS: ONE OF MANY HATS 2 concrete VOLUME 61 ISSUE 4
The proposal to delay implementation of these changes until May 2023 due to operating pressures was supported by Concrete NZ.
Consultation on updating the New Zealand Building Code has been aligned with the Building for Climate Change programme, with MBIE placing a heavy emphasis on improving the energy efficiency of homes. Seeking to make buildings healthier and more energy efficient, MBIE proposed options to increase the minimum wall and floor (plus roof and windows) insulation levels for new housing, as well as small and large buildings. The proposed options varied across the country based on a new set of climate zones.
While the guide - Whole-of-Life Embodied Carbon Assessment: Technical Methodology - is currently not a regulatory document, it is intended to be a high-level technical basis for the proposed future regulation of embodied carbon of buildings.
BUILDING CODE UPDATE
Broad engagement that considers all viewpoints will be crucial to creating a policy framework that encourages real business action towards the common goal of net zero emissions by 2050.
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CONTINUED ADVOCACY Government relations, in its many forms, will continue to be a priority for Concrete NZ. More so as the concrete industry tackles the complex issue of climate change through its 2050 roadmap for net zero carbon concrete.
• Tested by WSP
Concrete NZ has communicated its availability to assist the Commission understand pan-industry characteristics.
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Concrete NZ recently welcomed the opportunity to comment on the Commerce Commission’s consultation - Residential Building Supplies Market Study: Preliminary Issues Paper. The study is looking into whether competition for residential building supplies in New Zealand is working well and, if not, what can be done to improve it. In response, Concrete NZ emphasised that the Study needs to recognise the current abnormal market drivers and other factors affecting housing affordability, and that it should also consider product durability, embodied carbon (in terms of a full LCA) and environmental impacts.
• For restrained situations eg suspended slabs, residential floors, polished floors, in-fill slabs, etc
COMMERCE COMMISSION’S BUILDING SUPPLIES MARKET STUDY
Ngā mihi, Rob ChiefConcreteGaimsterNZExecutive
The Commission subsequently released a paper providing more detail about the approach and next steps for the study. As well as looking at factors affecting competition across the range of key building supplies, the Commission has identified three key building supplies which it will consider in more detail. The three key building supplies are plasterboard, structural timber and concrete (including cement).
Refer to any technical publication or Standard on concrete or concrete masonry produced since the mid-1970s and chances are David wrote it or was a significant contributor. Tireless in his efforts to implement relevant research and deliver practical training David always prided himself on developing strong HONORARY LIFE MEMBERSHIP RECOGNISES INDIVIDUALS FOR THEIR EMINENT CONTRIBUTION TO THE CONCRETE INDUSTRY. TO BE CONSIDERED FOR HONORARY LIFE MEMBERSHIP, A NOMINEE MUST DEMONSTRATE ATTRIBUTES INCLUDING SUSTAINED LEADERSHIP AND INDUSTRY MANA.
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DAVID BARNARD David started his career in the United Kingdom in 1952 developing his engineering experience in local government, contracting and consultancy before coming to New Zealand in 1974. Described as a “single-minded advocate for concrete” David spent close to 25-years at the Cement & Concrete Association of New Zealand (CCANZ), including its previous guises of the NZ Portland Cement Association and the New Zealand Concrete Research Association. David was also the New Zealand Concrete Society (now the Concrete NZ Learned Society) President from 1987-88.
David Barnard (Concrete NZ Honorary Life Member) and Rob Gaimster (Concrete NZ CEO).
CONCRETE NZ ACKNOWLEDGES
HONORARY LIFE MEMBERS
ROB GREEN Concrete NZ was very pleased to present Rob Green, recently retired from Higgins Concrete, with Honorary Life Membership.
Although David retired from his role at CCANZ in 1999 he remained busy as a consultant, including being Chair of the New Zealand Ready Mixed Concrete Association (now Concrete NZ) Plant Audit Scheme committee up until recently.
Examples of David’s achievements include the introduction of day-time training for concrete construction workers, the development of the Certificate in Concrete Technology & Construction correspondence course, and an emphasis on durability research that led to a chapter dedicated to the subject in NZS 3101 Concrete Structures Standard.
Rob Gaimster (Concrete NZ CEO), Rob Green (Concrete NZ Honorary Life Member) and Scott Ferguson (Higgins Concrete). relationships across the construction sector and imparting independent advice.
Concrete NZ salutes David for sharing his vision, intellect, wisdom and determination with the concrete industry and wider building and construction sector, and is extremely proud that he is the association’s inaugural Honorary Life Member.
Always steadfast in his belief that trade training is crucial to a healthy and progressive concrete industry, Rob’s contribution to BCITO - The Building & Construction Industry Training Organisation’s concrete National Advisory Group was instrumental in the ongoing development of many qualifications. More recently he has been actively involved with the Concrete NZ Readymix Technical Committee and the NZS 3104:2021 Specification for Concrete Production Standards Committee.
Rob’s focus on achieving quality outcomes has been to the benefit of many notable construction projects across the lower North Island, including the Te Apiti, Westwind Wind and Turitea wind farms.
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With close to four decades of experience in the ready mixed concrete industry, Rob is much admired by his former staff and colleagues for his excellent planning and organisational skills across all aspects of production and delivery.
During his career Rob served as President of the New Zealand Ready Mixed Concrete Association (NZRMCA) and as a Cement & Concrete Association of New Zealand (CCANZ) Board member.
Concrete NZ applauds Rob for all that he has achieved for, and given to, the New Zealand concrete industry, and wishes him all the very best as he continues to enjoy retirement.
AS PART OF THE CONCRETE INDUSTRY’S REVISED AWARDS STRUCTURE OVERSEEN BY CONCRETE NZ
JEFF MARCHANT Concrete NZ had the pleasure of recently acknowledging Jeff Marchant from BBR Contech with an Outstanding Contribution Award.
THE PEER-NOMINATED AWARD CELEBRATES THOSE WHO HAVE CONTRIBUTED MEANINGFULLY TO MAKING A VISIBLE DIFFERENCE IN THE FIELD OF CONCRETE DESIGN, CONSTRUCTION, MATERIAL SUPPLY AND/OR RESEARCH.
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Starting with BBR Contech in 1998, Jeff’s enthusiastic and innovative approach to post-tensioning design was instrumental in its widespread adoption for premium warehouse floors.
Jeff Marchant receives his Concrete NZ Outstanding Contribution Award from Concrete NZ Chief Executive, Rob Gaimster.
Colin Beavis receives his Concrete NZ Outstanding Contribution Award from Wilco Precast Managing Director, Andrew Sinclair.
CONCRETE NZ APPLAUDS OUTSTANDING CONTRIBUTORS
Accumulating 50 years of experience in the construction sector, Jeff is a recognised leader in the design of post-tensioned slab-on-grade.
To date Jeff has presided over approximately 3 million square metres of post-tensioned slab-ongrade in more than 400 building designs.
Highly respected for his technical leadership, Jeff’s contribution to the advancement of the concrete industry in New Zealand has been exceptional and Concretesustained.NZ,BBR
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Jeff has continued to refine and update his own design processes, while at the same time generously sharing his knowledge with engineers wishing to advance their skills.
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COLIN BEAVIS Concrete NZ recently had the privilege of presenting Colin Beavis of Wilco Precast Ltd with an Outstanding Contribution Award. Colin was recognised for his invaluable work in the precast concrete industry and wider construction sector. During his almost 50 years at Wilco Precast Ltd, Colin was a central figure in the establishment of Precast NZ Inc, which subsequently became the Precast Sector Group of Concrete NZ, remaining an ever-present member of the Executive Committee. He was a driving force behind industry ‘go-to’ technical documents on weathertight concrete construction, the safe handling of precast concrete, and architectural detailing. Colin was also a champion of trade training through his involvement with BCITO - The Building & Construction Industry Training Organisation.
MS575
Colin’s accomplishments and influence were instrumental in raising standards across the precast concrete industry, and in the development of the Concrete NZ Precast Plant Certification Scheme.
Contech and industry colleagues congratulate Jeff on his award.
In short, Colin’s passion for precast concrete and his wealth of knowledge are unsurpassed.
Concrete NZ, along with his peers, would like to take the time to thank Colin for all that he has done for the advancement of precast concrete in New Zealand, and wish him a very enjoyable retirement.
Notable projects that benefited from Jeff’s expertise include the award-winning K-Mart and James Pascoe Group (JPL) distribution centres in Auckland.
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Professor Alessandro Palermo University of Canterbury
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Current President of the Concrete NZ Learned Society, Alessandro’s research focuses on developing seismic resilient solutions for bridges and buildings, with a recent emphasis on sustainable materials/technologies and circular design.
Professor Alessandro Palermo, University of Canterbury
INTERNATIONAL BRIDGE AWARD FOR UNIVERSITY OF CANTERBURY PROFESSOR
THE 2021 ACCELERATED BRIDGE CONSTRUCTION (ABC) CONFERENCE AWARD COMMITTEE RECENTLY SELECTED PROFESSOR ALESSANDRO PALERMO FROM THE UNIVERSITY OF CANTERBURY AS THE RECIPIENT OF THE MOST INFLUENTIAL INTERNATIONAL ABC PERSON OF THE YEAR OUTSIDE U.S. IN ACADEMIA AWARD.
“Being recognised for this contribution is a great honour. The award is the recognition of the hard work that we collectively took on board since 2011. My research group, the NZ bridge engineering community, the Department and the NZ Natural Hazard Platform, a government founded research programme. The different drivers and expertise complemented so well that we had a seamless transition from research into practice. It was possible to implement one of the first ABC resilient bridge technologies only thanks to this unique collaborative approach. This recognition is not my award, but our award.”
MAXWELL SERCOMBE OF HEB CONSTRUCTION HAS BEEN PRESENTED WITH THE 2021 CONCRETE INDUSTRY APPRENTICE OF THE YEAR AWARD BY CONCRETE NZ AND BCITO, A BUSINESS UNIT OF TE PŪKENGA WORK BASED LEARNING LTD.
CONCRETE CONSTRUCTION WORKER SELECTED AS APPRENTICE OF THE YEAR
The pandemic greatly impacted both the construction sector and hospitality industry, leading to multiple postponements of Concrete NZ’s Conference, at which the Concrete Industry Apprentice of the Year is traditionally acknowledged. As such, Maxwell was joined by his HEB Construction colleagues and extended family, along with the Concrete NZ and BCITO teams at a recent function in Wellington dedicated to celebrating his achievements. In congratulating Maxwell, Concrete NZ Chief Executive Rob Gaimster, noted that the quality of entrants was exceptional, and included apprentices from precast manufacture, concrete
Maxwell and BCITO Maxwell Sercombe with the HEB Construction team.
Maxwell and Concrete NZ Maxwell and family
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Maxwell Sercombe
Raymond Puhara, Structures Training Manager at HEB Construction, congratulated Maxwell on his achievement, noting that it was obvious from the start that he was a go getter, punctual and reliable. “Max gives his all in whatever he does, and is definitely one of our future leaders.” says MaxwellRaymond.has recently moved from HEB Construction’s involvement on the completed Transmission Gully to the Te Ahu a Turanga: Manawatū Tararua Highway project between Ashhurst and Woodville.
* May promote an increased life and reduction in maintenance life costs, subject to the type of concrete mix design, concrete raw materials, application and PROPERTIESSTRENGTHIMPROVED shrinkagepermeability abrasion flexuralcompressive moeHIGHRESISTANCEABRASION shrinkagepermeability abrasion flexuralcompressive moePERMEABILITYLOW shrinkagepermeabilitytensile life cost* abrasion flexuralcompressive moe NZ 0800 657 156 concreteplus.co.nz Eden Innovations LLC is a wholly owned subsidiary of Eden Innovations LTD, Perth, Australia. Edencrete and the Edencrete logo are registered trade marks of Edencrete, used under license. placing and finishing, concrete production and concrete construction, making the judging process more challenging than is normally the case.
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“Maxwell’s maturity and focus helped to elevate him above other entrants, and he deserves applause for his enthusiasm, dedication and thirst for knowledge,” says Rob. “He has shown tremendous professional growth over recent years, which combined with his outstanding personal qualities, make Maxwell a worthy recipient of the award.”
Jason Hungerford, Director, BCITO expressed similar sentiments in praising Maxwell’s hard mahi and achievements to date, also noting that the function was an opportunity to celebrate with the people that have supported him on his learning “Injourney.conjunction
The Concrete Industry Apprentice of the Year award has gained great momentum since its inception in 2016 and is an important tool to celebrate apprentice success, the importance of trade training and the value of employer and family support. “Over recent years, the number of those enrolled in BCITO qualifications has increased dramatically, hitting 20,000 in 2021,” notes Rob. “Within this environment of trade training growth, the Concrete Industry Apprentice of the Year award highlights the fantastic opportunities available in the concrete industry for those contemplating a career in construction.”
with Industry Associations, apprentice awards are held each year across all BCITO trades,” says Jason. “For me, these awards are a culmination of everything we’re about at BCITO – training, learning, and rewarding excellence, and they reflect what we want everyone training in the construction sector to aspire to! Well done, Maxwell.”
GUIDE FOR NEW ZEALAND
CONCRETE NZ ACKNOWLEDGES ALL OF PRODUCTION FROM PLANT AND EQUIPMENT, TO ARE COVERED IN CONCRETE NZ PUBLICATION - CONCRETE FOR NEW ZEALAND.
ASPECTS
A section on concrete focussed New Zealand Standards, such as NZS 3104 Specification for Concrete Production and NZS 3109 Concrete Construction is included. Relevant health & safety, environmental, construction and transport legislation is also summarised to ensure the Guide is written specifically for New Zealand. Beyond those involved in the ready mixed concrete industry the Guide will be of use to engineers, contractors, builders and construction students, with the Guide used as a teaching resource for BCITO’s New Zealand Certificate in Concrete Production. Visit the Concrete NZ website to download the Concrete Production Guide for New Zealand –www.concretenz.org.nz
In addition to the science and technology behind concrete mix design, the Guide covers plant equipment (including its calibration), batching, ordering, dispatch and various testing procedures.
PRODUCTIONCONCRETE
CONCRETE
CONCRETE MIX DESIGN AND BATCHING, THROUGH
EQUIPMENT CALIBRATION, ORDERING, DISPATCH AND TESTING
THE LATEST
PRODUCTION GUIDE
12 concrete VOLUME 61 ISSUE 4
Often referred to as the single most widely used material in the world, or the second most used substance on the planet after water, at first glance concrete appears relatively simple to understand. It has three basic constituents - cement, water and aggregate, and although admixtures, additives (e.g. fibres) and colour pigments etc. can be introduced to the mix to modify fresh and hardened properties, we all recognise concrete as an uncomplicated building material, essential to our built environment and as a metaphor for permanence and strength. However simple in appearance, concrete is a complex, constantly evolving material, produced to exacting standards by operators with appropriate facilities, experienced staff and quality assurance programs.
Auckland Office 3 Bolderwood Place, Wiri 2104 0800 762 339 (0800 ROADEX) Bill O’Loughlin General Manager - Sales P: 09 277 0522 M: 027 284 4093 E: bill@roadex.co.nz www.roadex.co.nz Roadex provides business to business Road Transport services primarily for manufacturers supplying products to the Infrastructure and Construction sectors. REVISED TR3: ASR GUIDANCE UPDATED WITH INPUT FROM ACROSS INDUSTRY, TECHNICAL REPORT 3 (TR3) ALKALI SILICA REACTION: MINIMISING THE RISK OF DAMAGE TO CONCRETE: GUIDANCE NOTES AND RECOMMENDED PRACTICE, PREVIOUSLY PUBLISHED BY THE CEMENT & CONCRETE ASSOCIATION OF NEW ZEALAND (CCANZ), HAS BEEN REVISED. This 2021 Concrete NZ edition provides sufficient information based on current New Zealand experience and internationally accepted practices to enable the wider concrete industry to minimise the risk of Alkali Silica Reaction (ASR) damage in new concrete structures. The new edition supersedes the 2012 CCANZ version, with the principal changes being: • The maximum concrete alkali limit for normal concrete has been increased to 2.8 kg/m3 • Testing protocols have been updated to reflect international practice. • The provisions covering the use of supplementary cementitious materials have been updated. • Appendices have been expanded to include modern testing methodologies. The report’s recommendations comprise an acceptable solution to the requirements of NZS 3104 Specification for Concrete Production and NZS 3101 Concrete Structures Standard for minimising the risk of ASR damage in new concrete in New TR3Zealand.willcontinue to be updated as research, field experience, and international practice identify further improvements. Visit the Concrete NZ website to download TR3 Alkali Silica Reaction – www.concretenz.org.nz CONCRETE NZ ACKNOWLEDGESVOLUME61ISSUE4concrete 13
SCM RESEARCH 3. PERFORMANCEDURABILITY OF SCM CONCRETE Dr James Mackechnie A WIDE RANGE OF CEMENTITIOUS MATERIALS AVAILABLE IN NEW ZEALAND WERE ASSESSED FOR STRENGTH AND DURABILITY. Research findings are presented from concrete containing GP cement from two cement suppliers (Golden Bay Cement and Holcim New Zealand) together with established supplementary cementitious materials (SCMs) such as fly ash and slag, and natural pozzolans such as perlite, pozzolana and calcined clay. A summary of the different concrete mixes used for durability testing is shown in Table 1 together with compressive strengths. All concrete mixes were designed with a total binder content of 350 kg/m3 and water/binder ratio of 0.45 and SCM details are given below: • S1 GP cement from either Golden Bay Cement or Holcim New Zealand • S2 Huntly fly ash (ASTM class C) • S3 Adani fly ash (ASTM class F) • S4 New Zealand pozzolana (Golden Bay Cement) • S5 New Zealand perlite (Blue Pacific Minerals) • S6 Calcined clay (55 percent kaolinite clay from ConcreteGeraldine)wastested for a range of durability properties with the following being reported in the article – chloride resistance, carbonation resistance and prevention of expansion associated with alkali silica reaction. All concrete was cured in water until tested with the exception of accelerated carbonation, which had either 3, 7 or 28 days wet curing before drying for 7-days and then exposure to 2.5 percent carbon dioxide. MaterialsProperty H11H1 H12H2 H13H3 H14H4 H15H5 H16H6 GP 100% 70% 70% 70% 70% 70% SCM type 0% 30% Fly ash (C) 30% Fly ash (F) Pozzolana30% Perlite30% 30%CC Final w/b 0.4600.457 0.4540.451 0.4550.449 0.4570.454 0.4600.454 0.4650.460 assessmentWorkability GoodGood GoodGood GoodGood OKOK StickySeg. StickySticky 7-day(MPa)fc 51.651.8 45.638.5 43.537.2 43.738.4 27.332.4 49.841.8 28-day fc (MPa) 65.271.6 62.455.7 60.054.5 59.553.3 39.646.0 67.559.5 90-day fc (MPa) 72.178.0 78.673.3 76.576.3 72.071.0 48.860.5 71.270.6 180-day fc (MPa) 74.881.2 77.575.5 78.082.3 74.276.5 52.566.9 71.073.0 Table 1: Concrete mix designs and compressive strength results (Golden Bay Cement and Holcim New Zealand) 14 concrete VOLUME 61 ISSUE 4
Property(units) (days)Age 100%H1 GP 30%H2FA-C 30%H3FA-F 30%H4Pozz 30%H5Perl 30%H6CC Porosity(%) 9028 6.788.61 10.058.39 7.568.22 7.358.98 7.768.81 5.856.75 OPIscale)(log 9028 10.3810.41 10.269.92 10.2410.54 10.8210.56 10.5410.23 10.6110.72 (KOhm.cm)Resistivity 9028 11.189.32 10.059.13 10.0512.42 17.0910.40 12.669.23 30.2723.11 Table 2: Microstructural properties of concrete after 28 or 90 days curing MICROSTRUCTURAL ANALYSIS Concrete was tested at 28 and 90 days for microstructural properties affecting transport mechanisms affecting durability. A summary of properties is shown in Table 1 and includes: • Porosity measured by drying and vacuum saturation in water with dense concrete typically having values below 10 percent while every dense concrete has values below 7.5 percent. • Oxygen permeability index (OPI) is a log scale where low permeability concrete has values typically above 10.0 while values below 11.0 indicates virtual impermeability. • Resistivity is measured electrically with dense concrete having values greater than 20 kOhm.cm that may restrict the rate of corrosion in reinforced concrete. From this analysis some overall trends can be seen and are discussed below: • Fly ash concrete showed good microstructural quality after 90 days. • Concrete with pozzolana or perlite showed similar performance to fly ash concrete. • Concrete made with calcined clay had excellent microstructural properties. CHLORIDE RESISTANCE The chloride resistance of concrete was assessed using the rapid chloride migration test (NTB 492) with 28 and 90 day results compared in Figure 1. High levels of chloride resistance are typically achieved when concrete has migration coefficients below 5x10 -12 m2/s. Binder Type 101520253050 H1/H11 H3/H13 H5/15H2/H12 H4/14 H6/16(x10coefficientmigrationChlorinw 2-12m/s) 28G 28H 90G 90H Figure 1: Rapid chloride migration coefficients for SCM concrete Figure 2: Accelerated carbonation depths after 56 days exposure Binder Type 1015202550 H1 H3 H5H2 H4 H6 (mm)depthcarbonationAccelerated 3d 7d 28d VOLUME 61 ISSUE 4 concrete 15
exposure 16 concrete VOLUME 61 ISSUE 4
Longer-term chloride migration coefficients of SCM concrete was generally much lower than that of the control concrete (except for mixes containing perlite). Concrete containing calcined clay (mixes H6 & H16) had consistently better chloride resistance than other SCM concretes at 28 and 90 days.
• Concrete made with other SCMs (class F fly ash, pozzolana, calcined clay or slag) showed insignificant expansion or slight shrinkage after seven months that showed excellent ASR mitigation.
• Concrete made with class C fly ash or perlite allowed slow expansion that required several months to develop but showed significant expansion after six months.
CARBONATION RESISTANCE
The incorporation of SCMs into grade 4050 MPa concrete mix designs was found to produce a range of performance when microstructural and durability properties were compared. The durability performance of SCM concrete significantly improved with additional moist curing and when tested at greater ages. Having said that, no generalised trend was found for all concrete types as the materials produce a range of properties due to physical and chemical differences. All SCM showed the ability to improve chloride resistance over time provide concrete was well cured. Carbonation resistance of SCM concrete was generally poorer than concrete made with GP cement but it should be noted that comparisons were not made on the basis of standardised strength but were rather done using similar binder contents. ASR mitigation was improved when using SCM concrete especially when using class F fly ash, natural pozzolana or calcined clay (e.g. S3, S4 or S6). 2: Accelerated carbonation depths after 56 days
• Concrete made with GP cement and no other SCM had significant expansion in the first three months that indicated no ASR mitigation.
CONCLUSIONS
Time (days) (%)Expansion-CPT50 A1 A11A2 A12A3 A13 A16A14A4 A6A5 A15 AD-0.05Binder0.000.050.100.150.200.250.300.350.400 14 28 42 56 70 84 98 112 126 140 154 168 182 196 210 224 100% PC 30%30%FAGPL Figure
The carbonation resistance of concrete was assessed using EN 1920 that uses a high carbon dioxide concentration to accelerate the carbonation reaction in concrete. Concrete samples were exposed to 2.5 percent carbon dioxide for 56 days before being split open and the depth of carbonation using phenolphthalein indicator solution. Figure 2 shows a comparison of carbonation depth measured in the different concrete types exposed to three different levels of curing (e.g. 3, 7 or 28 days wet curing). Interim results from this testing found that some SCMs where able to suppress expansion associated with alkali silica reaction. Assessing the ASR expansion results, the following was found after seven months testing with CPT50:
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PAC0015CCT
GOLD (10+ YEARS)
• Allied Concrete, Penrose, Zone 3
• Firth Industries, Invercargill, Zone 1
The Scheme provides a thorough and objective audit of the quality systems in place at a ready mixed concrete plant to ensure compliance with NZS 3104 Specification for Concrete Production, the main Standard used to specify structural Theconcrete.management system of the Scheme conforms with the requirements of ISO 9001 and is independently audited by Bureau Veritas (New Zealand) Limited. Introduced in 2019, the Plant Audit Scheme Excellence Awards uses a Gold, Silver and Bronze Excellence Awards system to acknowledge commitment to quality across all aspects of ready mixed concrete production. To receive an annual Excellence certificate a plant must not have received any corrective actions or have its testing requirements questioned under the PlantsScheme.thathave demonstrated 3+ years of continuous Excellence are recognised as Bronze, those with 5+ years as Silver, and those with 10+ years as Gold.
• Allied Concrete Limited, Wanaka, Zone 1
PLANT FOR SECURING
• Allied Concrete, Setters Line, Palmerston North, Zone 2 • Terry’s Concrete Limited, Te Horo, Zone 2
FIVE PLANTS SECURE GOLD STATUS IN THE 2021 CONCRETE NZ PLANT AUDIT SCHEME EXCELLENCE AWARDS
SILVER (5+ YEARS)
• AML Limited, Christchurch North, Zone 1
STATUS IN THE
CONCRETE’S
CONGRATULATIONS TO ALLIED
• Allied Concrete, Tauranga, Zone 4
• Cromwell Certified Concrete Limited, Cromwell, Zone 1
• Allied Concrete Limited, Nelson, Zone 1
PLANTS,
• Allied Concrete Limited, Alexandra, Zone 1
• Higgins Concrete Limited, Richmond, Zone 1
‘EXCELLENCE AWARDS’. 18 concrete VOLUME 61 ISSUE 4
• Allied Concrete, Horotiu, Zone 4
• Allied Concrete, New Plymouth, Zone 2 CONCRETE’S NELSON, PENROSE AND SETTERS LINE (PALMERSTON NORTH) TERRY’S TE HORO PLANT AND ATLAS CONCRETE’S TAKAPUNA GOLD 2021 CONCRETE NZ PLANT AUDIT SCHEME
• Atlas Concrete Limited, Takapuna, Zone 3
• Allied Concrete Limited, Washdyke (Timaru), Zone 1
• Allied Concrete, Whakatane, Zone 4
“I look forward to seeing other members rise to the 10+ year challenge over the next 12-months, and be recognised for their dedication as Allied, Atlas and Terry’s Concrete have been in 2021.”
• Allied Concrete, Cambridge, Zone 4
• Allied Concrete Limited, Dunedin (Logan Point), Zone 1
• Firth Industries, Levin, Zone 2
• Allied Concrete, Matamata, Zone 4
• Allied Concrete, Ohau, Zone 2
• Atlas Concrete Limited, Kumeu, Zone 3
• Atlas Concrete Limited, Panmure, Zone 3
• PERTH Concrete Limited, Wanganui, Zone 2
BRONZE (3+ YEARS)
• Firth Industries, Aotea Quay, Zone 2
Allied Queenstown Concrete Limited, Frankton, Queenstown, Zone 1
• Allied Concrete, Silverdale (Furnace Road), Zone 3
• Atlas Concrete Limited, Silverdale, Zone 3
• Allied Concrete, Rotorua, Zone 4
• Allied Concrete Limited, Cromwell, Zone 1
• Christchurch Ready Mix Concrete Limited, Belfast No. 2, Zone 1
• Allied Concrete, Avondale, Zone 3
• Formstress Precast Limited, Waiuku, Zone 3
• Allied Concrete, Whitianga, Zone 4
• Bowers Brothers Concrete Limited, Hamilton, Zone 4
• Atlas Concrete Limited, Warkworth, Zone 3
• Allied Concrete, Bombay, Zone 3
Concrete NZ chief executive, Rob Gaimster, applauds the 2021 Gold status recipients for their unwavering commitment to producing quality assured ready mixed concrete.
“A member’s client can be confident that ready mixed concrete from a plant audited through the Scheme meets NZS 3104. This provides assurance that the concrete will achieve its strength and durability requirements in application.
• Allied Concrete, Otorohanga, Zone 4
• Pukepoto Ready Mix Limited, Kaitaia, Zone 3
• Firth Industries, Queenstown , Zone 1
• Bowers Brothers Concrete Limited, Matamata, Zone 4
• Allied Concrete Limited, Gore, Zone 1
“Concrete NZ’s Plant Audit Scheme remains the go-to mechanism for producers to demonstrate that their product meets mandatory industry Standards,” says Rob.
• Atlas Concrete Limited, Wiri, Zone 3
• Bowers Brothers Concrete Limited, Putaruru, Zone 4
• Allied Concrete Limited, Invercargill, Zone 1
• Christchurch Ready Mix Concrete Limited, Belfast No. 1, Zone 1
• Allied Concrete Limited, Ashburton, Zone 1
• Firth Industries, Rolleston, Zone 1
• Allied Concrete, Wanganui, Zone 2
• Allied Concrete, Gisborne, Zone 2
“It is wonderful to see Atlas Concrete and Terry’s Concrete join Allied Concrete in achieving Gold status, particularly when the operating environment has been so difficult due to the pandemic over the past couple of years.
•
• Allied Concrete, Taupo, Zone 4
• Christchurch Ready Mix Concrete Limited, Rolleston, Zone 1
Bernie Napp – Concrete NZ, Sustainability & Policy Director
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NEW
The idea of a Lee valley dam originated 22 years ago but came to a stop in 2018 when Tasman District Council voted down the project out of concern for costs rising above $100 million.
At the time Government was to introduce a bill for a Waimea dam to enable access to Crown land administered by the Department of Conservation, and by Land Information New TasmanZealand.District Council then did a U-turn after coming up with a new funding model to limit the burden on ratepayers. The law was duly passed with cross-party support, but not from the Green Party. The Waimea Dam will secure the region’s water supply for the next 100 years, improve water quality for a better environment for DAM
THE WAIMEA COMMUNITY DAM IS THE LARGEST BEING BUILT IN THE LAST 20 YEARS, THE FIRST CONCRETE FACE IN 50 YEARS, AND ONLY THE THIRD EVER IN NEW ZEALAND.
PLAINSRECHARGETOWAIMEA
For the region’s orchardists, grape and hops growers, and market gardeners, access to water is a constant worry and a brake on producing more, sustainably, from the land.
People living in Richmond, Brightwater, Mapua and elsewhere on the Waimea plains rely on local aquifers for drinking and other water supply, and in some years they run short.
people, plants, fish and animals, and maintain water flows in dry periods.
CONCRETE POURS
“The embankment face slipform pours in particular are hefty jobs,” says Andy Parker, Allied Concrete’s area manager for Nelson/Marlborough/West Coast.
This entailed trucking 4757 loads of concrete up to the dam, with not a single rejected load or health and safety problem recorded, with 14 staff on the job, day and night.
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In March 2019 Waimea Water Ltd opened access to the Lee Valley for heavy equipment and works, and then buried a “mauri stone” as a mark of respect to Papatūānuku. Construction proper began in September of that year; contractors include Fulton Hogan and Allied Concrete.
Pours started on a Tuesday morning at 6 am and finished 60-70 hours later, on either the Thursday or Friday depending on the speed of progress,
COUNTING THE BENEFITS
The job is a call for high-strength concrete mixes, containing 30 percent fly ash and around 2500 cubic metres of spray mix.
Tasman District Council’s stake is partly selffunded, and partly from central government and Nelson City Council contributions. The size of the prize is $55 million of forecast economic benefits to Nelson-Tasman in the dam’s first two years of operation, and $600-900 million over 25 years.
Irrigators Ltd has sourced funding equity contributions and a Crown irrigation investments loan, as well as loans from Tasman District Council that will convert to Waimea Irrigators equity as the loans are repaid with water usage.
Tasman District Council cracked how to pay for the dam by working with Waimea Irrigators Ltd to form a council-controlled organisation, Waimea Water Ltd. Shareholdings cover the project cost of $164 Waimeamillion.
Completion of the dam is expected in December 2022 when it will be 220 metres long, 53 metres high and 6 metres wide, containing 430,000 cubic metres of rock, and faced with concrete. It will take until next year for the lake behind the dam to form and to start delivering benefits to the region’s primary industries and residents, and to the health of the Lee and Waimea rivers. When full, the lake will contain 13 billion litres of “Wherewater.other dams function with lots of piping to extend the water supply to urban areas, we are using nature as the piping system. Topping up the river flows naturally will refresh and resupply groundwater aquifer levels,” Waimea Water Ltd’s website says.
“Under challenging conditions and terrain, the team has consistently delivered high quality work and service, including adhering to 145 environmental consent conditions, every load slump tested by the client, and every pour tested,” Parker says. “This has been a logistical nightmare at times organising staff and clients to get these over the line.”
MANAGING SEISMIC & FLOOD RISKS
Important to gaining resource consent for the dam is to manage seismic risk, as is the case for much infrastructure in New Zealand. Rock forms the core of the dam; reinforced concrete provides an external membrane and pulls the structure together. A grout curtain extends into the rock foundation for upstream waterproofing. The rock fill resists erosion, and it’s flexible – it can move during an earthquake to absorb seismic energy, and reduce the risk of subsequent failure.
A flow-limiting filter layer under the upstream face reduces leaks and movement in the dam over time. The dam has a spillway for water to flow safely in a maximum probable flood event without overtopping the embankment. An upstream debris boom prevents any logs entering the system.
On 18 May 2022, Allied Concrete finished the dam embankment face pours, totalling 23,786 cubic metres of ready mixed concrete. A nice touch to the project has been making friends with a local drove of feral pigs, now into their fifth generation. Rowdy the boar likes to keep an eye on everyone, and the team has returned the favour by giving him food now and then, and by making a little hut for the pigs to sleep in.
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DAM COMMISSIONING
with teams operating 24/7. The total was 14 pours, averageing 350 cubic metres per pour.
In the unlikely event of a leak, the dam would spill water gradually, and carry water safely to the toe of the dam via an open-graded drainage layer of high-quality rock. The dam design will resist up to a 1:10,000-year earthquake. Even if significant damage to the concrete face and/or movement of dam fill did occur, drainage layers in the dam would stem the resulting water flows, to avoid downstream damage.
During periods of drought the dam will provide water flows of no less than 2.2 metres per second into the two rivers, maintaining their ecological health and swimmability.
Joints in the dam prevent leakage between the foundation plinth and the concrete facing. These elements have primary and back-up PVC water stops.
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HOLCIM ANNOUNCES NEW LOW CARBON CEMENT REPLACEMENT FACILITY
CEO George Agriogiannis confirmed Holcim will import and distribute lower carbon cement replacement products, which will enable a reduction of construction-related embodied carbon. “I’m pleased Holcim is progressing to the building phase of a facility that will import and distribute low carbon cement replacement products.
Once operational, the site will enable reduction of carbon emissions via a cement replacement which can be used for applications such as infrastructure, commercial and residential projects.
This initiative is a positive step toward the New Zealand government’s Zero Carbon ambitions and Holcim’s Net Zero climate pledge,” said Mr Agriogiannis.
The facility will be adjacent to the company’s existing cement import terminal at Ports of Auckland.
HOLCIM NEW ZEALAND RECENTLY ANNOUNCED THAT IT WILL CONSTRUCT AND OPERATE A NEW FACILITY IN AUCKLAND.
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most commonly used building material in the world and a key component is cement, which has high embodied carbon due to its manufacturing process.
Currently, every year around 1.6 million tonnes of traditional cement is used in New Zealand, equivalent to approximately 1.3 million tonnes of CO2 By replacing cement with a product which has lower embodied carbon, but similar properties, construction-related embodied carbon can be significantly reduced.
At peak operation the site is expected to enable replacement of just under 100,000 tonnes of Ordinary Portland Cement, which will substantially reduce greenhouse gas emissions.
Annually, this is the equivalent of removing approximately 78,000 tonnes of carbon dioxide (CO2) or 40,000 cars*. Kevin Larcombe, Executive General Manager, Holcim New Zealand, confirmed the site will operate to maximise potential carbon reduction benefits.
Holcim is delivering lower carbon solutions in New Zealand and abroad, empowering customers to become more sustainable. Leading the way in green construction, Holcim was the first global building materials company to sign the United Nations Global Compact “Business Ambition for 1.5°C initiative”, with 2030 targets validated by the Science Based Targets initiative (SBTi). Holcim recently announced its 2050 goals, the first long-term targets in the building materials sector to be validated by SBTi.
“The new facility will be located within the Waitematā Port Precinct to enable efficient direct distribution to the market. By late 2022 construction is expected to be complete and the site fully operational,” said Mr ConcreteLarcombe.isthe
* Calculation of car emissions data sources.
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DUE TO BE ONE OF THE FIRST TO RECEIVE THE NEW HYDROGEN TRUCKS IN NEW ZEALAND, GOLDEN BAY CEMENT WILL SOON HAVE TWO HYZON-600HP 58 TONNE HYDROGEN-POWERED TRUCKS.
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Another step towards lowering the business’ carbon footprint, the trucks are being leased from TR TheGroup.Hydrogen fuel cells combine hydrogen (stored on-board the vehicle) and oxygen (from the atmosphere) to generate electricity that powers the vehicle. The only emission is water vapour. This will prevent approximately a tonne of CO2 emitted on a daily use.
ZERO EMISSIONS TRUCKS SET FOR USE IN NEW ZEALAND
As part of Firth Industries low carbon journey, they are eagerly awaiting the arrival of a new green machine - a battery powered concrete truck! In collaboration with the EECA (Energy Efficiency and Conservation Authority), the new Low Emission Transport Fund (LETF) will help Firth deploy a state-of-the-art battery-swap concrete mixer to operate in Auckland.
NZ’S FIRST BATTERY POWERED CONCRETE MIXER
Golden Bay Cement’s ‘Green’ trucks will have an expected range of 550-600 kms depending on weight and terrain.
Gian Raffainer, GM Cement Industrial at Golden Bay Cement explains, “There’s a total of 20 Hyzon trucks being brought to New Zealand by TR Group and for us to obtain two, it’s a total privilege.”
“These trucks will demonstrate how hydrogen can be a Initiallyreliable.”Golden Bay Cement will be trialling these trucks in the Auckland area and will assess further expansion as infrastructure for fuelling stations continues to grow.
CONFERENCE 2022 13-15 OCTOBER 2022 ENERGY EVENTSROTORUACENTRE
AMC TAKE HOME TOP HONOUR IN RECENT NZCCA AWARDS THE MAIDSTONE SKATEPARK IN UPPER HUTT, NORTH OF WELLINGTON. 28 concrete VOLUME 61 ISSUE 4
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Images: Maidstone Max - Tô Tâtou Papa Tâkaro. Upper Hutt City Council. Upper Hutt City Council knew they had a safe pair of hands in Angus McMillan Concrete (AMC), one which ticked all the right boxes, to bring this treasured play area to local residents.
Adopting a collaborative approach that used local labour and resources, AMC achieved a high-quality outcome for this new, but already much-loved community resource. With concrete stretching across 4,000 square metres, the skatepark includes an impressive pump track made-up of rollers and bermed corners, a basketball half-court and paths leading in and out of the accompanying new playground.
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In addition to the customary bowls and ramps, a standout feature is a 3.5 metre piece of ‘skateable art’ that proudly incorporates the name of the park and exemplifies the social aspects of sustainable development. Arguably New Zealand’s pre-eminent skatepark builder, AMC continues to expand boundaries and deliver ever-larger and more-complex projects, as exemplified by the Maidstone Skatepark. To make sure the judges were fully satisfied with their decision to present AMC with the Supreme Award they despatched a team of 14-year-old skating and “scootering” experts to drop into the bowl and do some nose pivots, fakies, 180s and bar spins. They were impressed. Check out their video report on YouTube
CONCRETE NZ LEARNED SOCIETY SEMINAR VIDEOS CONCRETE MATERIALS Presenters Dene Cook of Firth Industries and Dr James Mackechnie cover: • AS/NZS 4671:2019 Steel for the Reinforcement of Concrete • NZS 3104:2021 Specification for Concrete Production • TR3 Alkali Silica Reaction: Minimising the Risk of Damage to Concrete (2021 Ed.) • Sustainable concrete using SCMs INDUSTRIAL FLOORS Presenters Martin Lincoln of Certus Consulting, Alan Ross of Conset Construction and Tim Walker of Conslab cover: • The latest developments in industrial floors • Common issues with the design and construction of industrial and suspended concrete floors • Methods for assessing surface regularity • Demonstrations and examples of how to measure and assess surface regularity • Technical Specification 01:2021 - Surface Regularity Requirements for Concrete Floors PRESTRESSED CONCRETE 101 Supported by BBR Contech, presenters Dr Alessandro Palermo of the University of Canterbury and Dr Moustafa Al-Ani of Compusoft Engineering cover: • Fundamentals of pre- and post-tensioned concrete members • Materials and prestressing technology • Design and checks for SLS and ULS • Worked example STRUT & TIE Presenters Des Bull of Holmes Consulting Group and Dr Rick Henry of the University of Auckland •cover:Strut and tie modelling theory • Concepts for simple strut and tie models • Strut and tie observed performance • Strut and tie design compliant with NZS 3101 • Examples of strut and tie for real scenarios ASSESSMENT OF EXISTING CONCRETE BUILDINGS USING THE REVISED C5 GUIDELINES Presenters Dr Ken Elwood of University of Auckland and Dr Nicholas Brooke of Compusoft Engineering cover: • Assessment philosophy and materials • Deformation capacity of columns, column shear strength and deformation capacity of walls • Loss of gravity support for columns, slabcolumn connections and walls • Elements containing plain round reinforcement and with deformation at a single crack • Assessing diaphragms containing mesh VisitreinforcementtheConcrete NZ website to gain paid access to the Learned Society’s seminar videos – www.concretenz.org.nz THE LEARNED SOCIETY HAS AVAILABLE FOR PURCHASE THE SEMINARS BELOW. VOLUME 61 ISSUE 4 concrete 31
NEW ZEALAND PUBLIC HOUSING PILOT SHOWCASED AT UN CLIMATE CHANGE CONFERENCE
Ngā Kāinga Anamata, meaning ‘homes of the future’, is a sustainability project aimed at driving carbon emission reduction in New Zealand’s construction industry. The project was selected as one of only 17 initiatives worldwide to be on show in the COP26 Build Better Now virtual pavilion from late 2021. The project will deliver 30 new homes within five, three-level apartment buildings in Auckland’s Glendowie. Each near identical building will use a different construction technology1, enabling sustainability insights to be gathered on a range of building materials and systems.
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AN
Kāinga Ora Commercial Director Matt Noyes, says Ngā Kāinga Anamata has a firm focus on achieving the Government’s carbon emission targets, with significant benefits to occupants. “The buildings will achieve significantly reduced carbon and energy outputs; achieving both Passive House standard and net zero energy,” he says. “By focusing on the trifecta of using low carbon materials, operational energy efficient solutions and local renewable energy generation we have managed to slash lifecycle carbon emissions to INNOVATIVE NEW KĀINGA ORA PUBLIC HOUSING PILOT TACKLING CLIMATE CHANGE IN THE BUILT ENVIRONMENT RECENTLY FEATURED ON THE WORLD STAGE AT THE UNITED NATIONS CLIMATE CONFERENCE (COP26).
Ngā Kāinga Anamata also aims to address biodiversity loss, actively protecting, restoring and supporting local ecosystems. Planned native biodiversity corridors and large pockets of regenerated native forest will provide a network of plant life supporting insects, birds and other animals so they can co-exist and thrive alongside the new development.
•Precast concrete products •Building foundations •Commercial buildings
For more information visit the Ngā Kāinga Anamata website - kaingaora.govt.nz/ngakaingaanamata
•Road and bridge construction • Basements a fraction of what they are in a traditionally New Zealand built home. Construction and monitoring of these buildings will now help us understand the overall cost and benefits of lowcarbon public housing, and report our insights back to the industry.
Kāinga Ora Board Chair Vui Mark Gosche says global recognition of the industry-leading development is significant for Kāinga Ora.
“Importantly, the individuals and whānau who will live in these homes will enjoy a high performing, thermally comfortable and healthy home, and a genuine solution to fuel poverty.”
The Build Better Now virtual pavilion is an open virtual exhibition and events series highlighting the built environment’s role in tackling the climate and biodiversity/ecological crises. Visit the Build Better Now website - buildbetternow.co
• Water treatment tanks
“The homes we build today will set the path for our carbon emissions in the decades to come. We need to be part of the solution, driving innovation and transformation now to ensure good health and climate safety for future generations.”
With construction having just begun, the public housing development will achieve MBIE’s Building for Climate Change programme targets, reaching the proposed 2030 final operational efficiency cap by 2024; six years ahead of expectation.
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“Build Better Now involved a rigorous selection process, and the successful projects are those making an immediate positive impact on both the planet and people’s lives. As a major property developer and public housing landlord these outcomes are critically important to Kāinga Ora,” he says. “Ngā Kāinga Anamata seeks to resolve many underlying problems with the housing sector in Aotearoa and is the start of a national response to climate change mitigation in the built environment.
ABOUT BUILD BETTER NOW AT THE COP26 BUILT ENVIRONMENT VIRTUAL PAVILION Build Better Now is a collaborative project co-owned by over 100 partner organisations from across the built environment sector, for which UKGBC is acting as a secretariat. This coalition has come together to ensure that the sector’s key role in addressing the climate and ecological emergencies is brought to the forefront - in the run-up to, during and far beyond COP26. The Virtual Pavilion aims to showcase the relationship between the built environment and climate change, both as a part of the problem and the solution. It will comprise an exhibition of global exemplar projects and places, within a bespoke virtual reality (VR) space, as well as a major series of events and downloadable content – to include keynotes, panel discussions and more. PROJECT DETAILS • 5 x three storey walk-up buildings, each using a different construction method • 30 x two-bedroom homes in total • Each building will achieve Passive House standard and will be net zero energy • Expected construction period: Q1 2022 to mid-2024 • 3 other buildings not part of the R&D project will also be built within the development PROJECT PARTNERS • Building Research Association of New Zealand (BRANZ) • Context Architects - Architects • Robert Bird Group – Structural Engineers • Aurecon – Services Engineers & Passive House Designer • Resilio Studio – Landscape Architects • Ortus International – Quantity Surveyors • Sustainable Engineering – NZ Passive House Certifiers • Revolve – PV System Designers • Marshall Day – Acoustic Engineers • Holmes Fire – Fire Protection Consultants 1 The five construction materials used are: mass timber/cross laminated timber (CLT); light timber frame (LTF); precast concrete; light gauge steel and a hybrid CLT/LTF. 34 concrete VOLUME 61 ISSUE 4
Bring Comes in all available ReidBar™ diameters: 12mm, 16mm, 20mm, 25mm & 32mm SystemGroutReidBar™Sleeve
RAVENSCAR HOUSE MUSEUM: A REMARKABLE GIFT TO ŌTAUTAHI WHEN ŌTAUTAHI CHRISTCHURCH’S STRIKING PURPOSE-BUILT RAVENSCAR HOUSE MUSEUM OPENED TO THE PUBLIC LATE LAST YEAR, IT WAS THE REALISATION OF A LONG-HELD DREAM. Image: Ravenscar House Museum interior. Photos: Stephen Goodenough/Canterbury University Press 36 concrete VOLUME 61 ISSUE 4
The story of this remarkable project, the personalities behind it and the context of a post-earthquake city are beautifully explored and illustrated in Ravenscar House: A Biography, written by Christchurch journalist and writer Sally Blundell and published by Canterbury University Press.
Jim and Susan Wakefield’s vision was to create an architecturally significant building to house and share their impressive collection of art and artefacts, including works by leading New Zealand artists such as Frances Hodgkins, Colin McCahon and Bill Sutton.
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Both studied at the University of Canterbury (UC). Susan gained a PhD in Russian literature but made her career in accounting. She was recognised with a Queen’s Service Order for Public Service and an honorary doctorate from UC for her service, including as chair of the Commerce Commission. Jim’s successful career in accountancy and commercial leadership, which saw a string of companies prosper under his direction, was launched with a Bachelor of Commerce at UC.
The story of resilience, architectural ingenuity and generosity begins in a sense with the demolition of the original Ravenscar House on Scarborough Hill, the Wakefield’s home, following the Canterbury earthquakes. Blundell, however, takes us much further back – to Susan’s childhood in Lincolnshire, England, and Plimmerton, north of Wellington, to Jim’s upbringing in Timaru, and through their outstanding careers and lives together.
The Ravenscar House Museum story is also about collaboration, with Canterbury Museum playing a starring role, closely followed by the Christchurch City Council, UC and the people of Christchurch.
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“This was an intriguing project to work on,” Blundell says. “It is the story of Jim and Susan’s shared love of art and antiquities, the story of the Christchurch earthquakes and the story of New Zealand’s limited tradition of house museums, all wrapped up in an extraordinary work of architecture.”
Image: Ravenscar House Museum interior. Photos: Stephen Goodenough/Canterbury University Press Image: Author Sally Blundell. Photo: Stephen Goodenough
Ravenscar Trust Collection as an enduring legacy for the Theycity.”found that steward in Canterbury Museum, which has now been gifted the new Ravenscar House, and operates the Ravenscar House Museum as a home to the Ravenscar Trust Collection and as a major visitor attraction.
Architects Patterson Associates, HRS Construction, Suzanne Turley Landscapes and other professional contributors are acknowledged for the essential roles they played in the creation of the building and “Againstgarden.pressing deadlines, storms, the tragic mosque shootings of March 2019 and the COVID-19 pandemic of 2020, they managed to keep to an ambitious timeline with professionalism and, amazingly, unswerving good humour,” Steve Wakefield writes. The result, writes Canterbury Museum director Anthony Wright, is a nod to the old Christchurch, “but it also stands sentinel to the new spirit of the city in the heart of the cultural precinct. The calibre of its architecture meets the calibre of the philanthropists’ vision and contributes a vibrant new presence and attraction to the city.”
Jim’s son and Ravenscar Trust Chairman Steve Wakefield pays tribute to Jim and Susan in his foreword: “It is extraordinary now to think of the resolve they showed when, in their late seventies and sixties respectively, they brushed themselves down from the loss and shock of the earthquakes and picked up their plan to build a new Ravenscar House and to find an appropriate steward for the
The richly illustrated book, with photography by Stephen Goodenough and Duncan Shaw-Brown, was designed by Aaron Beehre.
We produce and supply consistent quality cement that you can rely on. We call it NZ grade - you know where it’s made, what it’s made of, who made it and that it’s made for the NZ market. It’s Genuine so you can trust it. Being Genuine is part of our fundamental approach to do business.
WITH HELP FROM AUSTRALIAN UNIVERSITIES, A NEW CARBON NANOTUBE LIQUID ADDITIVE THAT EXTENDS THE DESIGN LIFE OF CONCRETE PROJECTS IS SAFE AS WELL AS EFFECTIVE.
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An innovative process developed in Australia is now bringing exceptional levels of strength and durability to concrete through EdenCrete products.
The idea originated when scientists wanted to find uses for the carbon nanotubes (CNTs) created when converting methane gas into hydrogen.
Scientists found that adding CNTs to a concrete mix created stronger, more durable structures with many positive characteristics that surpass those provided by other mixes. CNTs are very fine and extremely tough. When added to concrete mixtures the nanotubes fill the spaces at a nanoscopic level between the hydrated cement particles. As the concrete cures, the nanotubes create millions of flexible, strong carbon bridges throughout the structure. The result is improved abrasion, flexural, tensile, compressive and permeability characteristics.
“We worked closely with industry to develop these products. It’s one of the main reasons that the mix is provided in liquid form and not powdered form. EdenCrete can help to improve the design-life of structures and allows for more sustainable choices to be made by reducing the overall amount of cement used in structures,” said Larsen.
Australian results from tests show exceptional performance can be achieved when EdenCrete is used. In a car park environment in Brisbane, the design life of a structure was increased by 27 percent to 90 years and saw a 27 percent reduction in overall repair costs, according to the Life-365 durability model. A similar car park environment test in Victoria saw a 55.7 percent longer initial life, while tidal environments saw up to 133 percent extra initial life. The product is suited for engineers looking for additional durability in marine, underground, or oil and mineral sands environments, where corrosion is a concern. It also has positive attributes for environments needing improved abrasion resistance such as roads, pavements, heavy traffic, commercial and industrial areas.
Allan Godsk Larsen is Chief Scientist at Eden Innovations Ltd, the company that commercialised the pyrolytic process and created the EdenCrete range of products. They partnered with the University of Queensland, Monash University and Deakin University throughout the various stages of development.
AUSTRALIAN INNOVATION BRINGS THE STRENGTH OF CARBON NANOTUBES TO CONCRETE
While there are safety concerns when dealing with carbon nanotubes in dry powdered form,
EdenCrete products only come as liquid mixes for safe handling. Once bonded and crystallised within the concrete, carbon nanotubes are very difficult to return to their earlier form. Tests by Eden Innovations also show that CNTs remain bound in the matrix of concrete and that actions such as sawing, crushing or dismantling do not cause them to become freed or airborne.
EdenCrete has just recently become available in Australia and is finding advocates in the construction industry. Brodie Chan is a Project Engineer at Port of Brisbane, which has recently been trialling EdenCrete. Chan says the trial has yielded positive results with enhanced porosity, durability, compressed strength and other characteristics.
“For us, we take great care around maximising the expected life of structures in and around our ports. They are extremely expensive to replace at a later stage, so we take great interest in products that can extend the life of concrete structures, roads and bridges in or around a marine environment,” said Chan.
Prior to COVID-19, and exacerbated by the Suez Canal blockage, supplies of silica fume have been difficult to source here in Australia, according to feedback Parchem has received from construction companies. Silica fume is an effective pozzolanic material added to concrete for improved strength and abrasion resistance. EdenCrete can be added to these concrete mixes, significantly reducing the amount of silica fume required to achieve the improved characteristics. There are two types of EdenCrete products currently available, each with a shelf-life of 12 months. EdenCrete is designed to add strength and durability to any type of concrete mix. EdenCrete Pz is designed to add strength and durability for concrete using fly ash and/or slag as a replacement for cement.
“EdenCrete brings the strength of carbon fibre to concrete while coming from a sustainable process that helps to reduce methane emissions. There are plenty of ways it can be used to help make structures stronger, more durable and reduce our reliance on other, less sustainable materials.”
The EdenCrete products were first commercialised in the US where they have found support among key infrastructure organisations such as the Department of Transport in Georgia. Following successful trials, the Department has added EdenCrete as a specified liquid additive to use for any highway repairs.
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She has been liaising with construction companies throughout the region to make sure they are aware of the new product. “We’re here to help engineers and companies around Australia make use of the wonderful properties of EdenCrete. We can share Allan’s test results and provide other resources for use with the Life-365 open-source software. We’ll also supply the parameters for you to work out simulated age of structures across various environments using the chloride diffusion coefficient test results,” said Eagle.
Tasha Eagle is the ANZ Business Development Manager for Concrete Admixtures and Cement Additives for Parchem Construction Supplies, which is part of DuluxGroup and the licensed distributor of EdenCrete in Australia and New Zealand.
In The Library, historians Andrew Pettegree and Arthur der Weduwen introduce us to the antiquarians and philanthropists who shaped the world’s great collections, trace the rise and fall of literary tastes, and reveal the crimes committed in pursuit of rare Inmanuscripts.doingso,they reveal that while collections themselves are fragile, often falling into ruin within a few decades, the idea of the library has been remarkably resilient as each generation makesand remakes - the institution anew.
FULTON’S CONCRETE TECHNOLOGY (10TH ED.) MARK ALEXANDER (EDITOR) Fulton’s Concrete Technology is a classic work in the literature of concrete. First written in 1957 by Frederick ‘Sandy’ Fulton – head of the then Concrete Association of South Africa – it has now been reissued with an additional ten chapters. Over 64 years, the book’s scope has been adjusted to reflect technical developments and changing priorities. This edition emphasises environmental sustainability, a thematic thread woven throughout the fabric of the work while, as a reflection of increasing technical complexity, the largest section is that devoted to special concretes. To achieve the increasing breadth of subject matter, this edition is a multi-authored compendium, with the 37 chapters individually prepared by specialists and Cementpeer-reviewed.&Concrete SA rightly claims ‘Fulton’ to be “established as the authoritative text on concrete materials and practice in South Africa” and, with many distinguished contributors, has considerable value on the international stage too. Contact info@cemcon-sa.org.za to purchase.
THE LIBRARY: A FRAGILE HISTORY BY ANDREW PETTEGREE & ARTHUR DER WEDUWEN Perfect for book lovers, this is a fascinating exploration of the history of libraries and the people who built them, from the ancient world to the digital age. Famed across the known world, jealously guarded by private collectors, built up over centuries, destroyed in a single day, ornamented with gold leaf and frescoes, or filled with bean bags and children’s drawings - the history of the library is rich, varied, and stuffed full of incident.
CONCRETE NZ LIBRARY LISTED BELOW IS A SELECTION OF RECENTLY ACQUIRED MATERIAL BY THE CONCRETE NZ LIBRARY. MEMBERS CAN EMAIL LIBRARY@CONCRETENZ.ORG.NZ TO BORROW.
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Congratulations to Johann Zarco of MacPrac Ltd, who correctly answered the Vol. 61 Iss. 03 Library Quiz to receive a copy of The New Net Zero: Leading-Edge Design and Construction of Homes and Buildings for a Renewable Energy Future by Bill Maclay.
Chair: Kerry Newton Convenor: Rob Gaimster Concrete NZ Masonry Sector Group Ph (04) 499 8820
Email your answer to library@concretenz.org.nz
12,000 years ago, the development and uses of new binders by the Chinese, ancient Greeks and Romans, spanning from England and Continental Europe to the New World, and finally the present, are all illustrated. Not only is an overview of the technical and historical sequence of individual events provided, but the political and economic environments of the times are described. The people who made a particular theoretical or practical contribution to the development and application of cement and concrete are also introduced. Through the combination of text and pictures, the book is colourful, interesting, highly instructive and exciting.
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To go in the draw to win a copy of Illustrated History of Cement and Concrete: The Exciting Development of Two Outstanding Building Materials by Rainer Nobis answer the following question: Who was recently named Concrete NZ’s inaugural Honorary Life Member?
CONTACTS
Concrete ReadymixNZSector Group Ph (04) 499 0041
BYBUILDINGTWODEVELOPMENTTHEANDHISTORYILLUSTRATEDOFCEMENTCONCRETE:EXCITINGOFOUTSTANDINGMATERIALSRAINERNOBIS
The book is aimed at all those who work with the building materials cement and concrete, be it in the construction or building materials industry, including civil and structural engineers, architects, teachers, students as well as interested laypersons.
LIBRARY QUIZ
Chair: John Marshall Convenor: Dave McGuigan
Chair: Dene Cook Convenor: Ralf Kessel Concrete NZ Learned Society Ph (04) 499 8820 President: Alessandro Palermo Convenor: Adam Leach Concrete GroupReinforcingNZStakeholder Ph (04) 499 8820 Chair: Kelvin Busbridge Convenor: Dave McGuigan Concrete NZ Precast Sector Group Ph (04) 499 8820
This book is the first to describecomprehensivelythehistory of cement and concrete and their materialsproducedsignsStartingeasilydevelopmenthistoricalinanreadableform.withthefirstofartificiallybuildingmorethan
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