ISSUE 74 2022
Specialising in stainless steel and its applications
Photo credit: Brisbane City Council
FEATURE
Kingsford Smith Drive STAINLESS FOR THE LONG RUN Brisbane’s Kingsford Smith Drive upgrade saw Australia’s largest use of stainless steel reinforcement bar to date, transforming the structural performance of one of the city’s busiest roads. An initiative of Brisbane City Council and designed and constructed by Lendlease, the Kingsford Smith Drive upgrade involved widening the 7km road from four to six lanes between Theodore Street at Eagle Farm and Cooksley Street at Hamilton. This was achieved via a retaining wall built between 10m to 15m out into the Brisbane River. As a major road corridor, Kingsford Smith Drive links the Brisbane CBD to Brisbane Airport, the Port of Brisbane and residential and economic growth areas including Northshore Hamilton and the Australia TradeCoast region. Planning for future traffic volumes, construction commenced in 2016 to deliver increased road capacity and improved public transport, pedestrian and cycle facilities. Critical to the upgrade and structure was the extensive use of stainless steel. ASSDA Member Valbruna Australia supplied 800t of grade 2304/1.4362 Reval® stainless steel in 12mm, 16mm and 20mm stainless steel reinforcement bar (rebar), which was used in the tidal zone to 1m above the Highest Astronomical Tide (the splash zone) of the precast fascia panels and in the lowest of the precast cantilever panels that fell within the splash zone.
... when specified correctly [stainless steel rebar] provides a minimum service life of 100 years in concrete, reducing lifecycle costs.
2 – Australian Stainless Issue 74
Images courtesy of Brisbane City Council
The Brisbane River is a tidal estuary, and duplex stainless steel reinforcement meets the service life demands of structures in a brackish water environment. Stainless steel reinforcing resists chloride attack and pitting corrosion, and when specified correctly, provides a minimum service life of 100 years in concrete, reducing life-cycle costs. Kingsford Smith Drive carries an average of 70,000 vehicles per day, and stainless steel rebar delivers confidence in the strength, durability and structural performance expected of critical public infrastructure.
and the top rail was specified to follow the flow of the river, presenting several challenges in its fabrication and installation. Furthermore, the top rail was specified to be delivered in 10m lengths. It was TIG-welded on-site using grade 316 stainless steel 150x50x5mm rectangular hollow sections (RHS) with a 600-grit finish supplied by Stirlings Performance Steels. Different methods were trialled to achieve the curve specified and conventional manual means were applied to bend the RHS in-between the posts.
The scheduling, cutting and bending of the stainless steel rebar to tight precast tolerances was performed by Mesh & Bar. Furthermore, Valbruna supplied approximately 5,000 grade 2205 stainless steel terminator couplers, used to simplify rebar placement and create anchorage within the concrete.
Stainless Engineering Services fabricated the stainless steel spigots from 32mm plate to suspend and clamp the galvanised balustrade panels, as well as other various stainless steel components including planter boxes, rung ladders for sewer and drainage manhole access and cover plates at all expansion joints along the boardwalk.
Stainless steel was also delivered in spades for various other components of the project, with ASSDA Member and Accredited Fabricator Stainless Engineering Services engaged for the fabrication and installation services. Fortytwo road bridge expansion joints were fabricated in their workshop using 15t of grade 2205, 10mm and 16mm stainless steel plate, with material supplied by ASSDA Member Stirlings Performance Steels. The cantilever bridge deck was constructed in 40m long concrete sections, and the expansion joint fixings were countersunk and bolted insitu to deliver a continuous smooth surface.
Stainless steel tube was also used for 300m of pedestrian and bike rails at Cameron Rocks Reserve, with material supplied by ASSDA Members Australian Stainless Distributors and Midway Metals.
Additionally, Stainless Engineering Services delivered 1.5km of stainless steel top rails for the Lores Bonney Riverwalk, Kingsford Smith Drive’s riverside promenade. The riverwalk meanders from Bretts Wharf to Cameron Rocks Reserve
With the Brisbane River at its doorstep, the use of stainless steel throughout the project has delivered several key benefits in ensuring the longevity of public infrastructure in a marine environment. Structural durability, corrosion resistance and visual appeal are just some benefits that stainless steel has contributed to the precinct’s improvement and development. Completed in 2020, the Kingsford Smith Drive upgrade has delivered up to 30% travel time savings for all vehicles, 7km of new and improved pedestrian and cycle paths, and enriched urban amenities and green spaces for locals and visitors.
ASSDA MEMBER CONTACTS Australian Stainless Distributors \ Cooper Bailey \ 07 3266 6211/0437 484 815 \ cooperbailey@asdsales.com.au \ stainlesssteelasd.com.au Midway Metals \ Craig Wallace, Brisbane Manager \ 07 3382 9500 \ craigw@midwaymetals.com.au \ midwaymetals.com Stainless Engineering Services \ Richard Shilling, Director \ 07 3204 2845 \ richard@stainlessengineering.com.au \ stainlessengineering.com.au Stirlings Performance Steels \ Adam Vesly, Business Development Manager - Queensland \ 07 5631 0300 \ adamv@stirlingsps.com \ stirlingsps.com.au Valbruna Australia \ Shane Gent, QLD Branch Manager \ 07 3807 9733/0498 325 971 \ shane.gent@valbruna.com.au \ valbruna.com.au
3 – Australian Stainless Issue 74
TECHNICAL
Stainless steel reinforcement STANDING THE TEST OF TIME
Stainless steel reinforcement (rebar) is increasingly being specified for its excellent corrosion resistance, long-term performance and economic benefits. There are many advantages to using stainless steel rebar: E xcellent durability, fire resistance and structural performance. Exceptional corrosion resistance in harsh marine environments, resisting chlorides and pitting corrosion. E xtended service life and reduced life cycle costs. inimal maintenance costs and therefore less M disruption of service for refurbishment or replacement. E asy to cut and bend, good weldability.
Cathodic protection is not required. Reduced concrete cover, minimising costs and delivering a more lightweight, higher tensile structure. Cracks are less critical and concrete surface treatments are not required. Supplied in accordance with ASTM A955 and BS 6744 standards, both of which require confirmation of a generic corrosion resistance test by the manufacturer to meet specific strength levels.
Some history Concrete is the most used material in infrastructure projects because of its properties, cost and availability. It has excellent compressive strength but very poor strength under tension. Cast iron and steel bars were incorporated into structures to form durable and strong reinforced concrete with the steel protected by the alkalinity of the concrete. Unfortunately, a combination of cost-cutting (poor quality concrete) and atmospheric CO2 carbonation led to the prevalence of concrete cancer with reduced service life and durability. In the USA, multiple reinforced slab highway bridges suffered severe reinforcement corrosion and state authorities explored galvanising, epoxy coatings and cathodic protection in refurbishment and new programs. The UK Government had similar concrete corrosion problems at Birmingham’s Spaghetti Junction and research led to the 1990s revision of their BA 84/02 Design Manual for Roads and Bridges. The new code required stainless steel reinforcement around slab penetrations, in splash zones or wherever severe disruption would occur if carbon steel repairs would be required. It also permitted lower cover and wider cracks if stainless steel was used compared to the carbon steel requirements. In addition, it removed the requirement for surface diffusion barriers such as silane treatments. Over the following decades this philosophy migrated into commercial buildings and non-government infrastructure.
Photo credit: Nickel Institute
An outstanding example of stainless steel rebar use is at Progreso Pier in Mexico. Constructed in 1941 using 304 reinforcement, it is still operating today without any significant maintenance or repairs. According to a Nickel Institute life-cycle assessment over a 79-year period, the lifetime cost of the lower original cost of an alternative carbon steel reinforced structure is now 44% higher than actual Progreso Pier costs. In 1969, a much smaller pier was built alongside the Progreso Pier using carbon steel rebar and as pictured, did not stand the test of time.
Why stainless steel?
Product forms and inspection
When carbon steel corrodes, the oxides are up to 10 times the volume. This expansion will start cracks in the concrete and possibly surface stains. This allows more water, oxygen and chlorides to accelerate the steel attack, cause concrete spalling, further corrosion and potentially, structural failure. Stainless steel is inherently resistant to corrosion and, even if it is exposed to overwhelming chlorides in concrete, the pitting attack does not generate sufficient localised corrosion product to fracture the concrete. Despite the short-term attack of galvanised coatings in fresh concrete, galvanised reinforcement was trialled but did not offer sufficient long-term durability. Epoxy coated steel reinforcement suffered from handling and installation damage leading to concentrated attack at coating holidays. The solutions of cathodic protection (CP) and sacrificial anodes for carbon steel reinforcement can be effective. However, the reinforcement must be electrically continuous, the operation of the system must be regularly monitored, and periodic surveys are required to monitor the distribution and effectiveness of the CP. In a bridge designed for a 300-year service life, the monitoring costs would be significant.
Bar, and bar with defined deformations, are specified with recommended sizes that do not always match hard metric dimensions. Stocked sizes depend on the specific supplier. It is typical that bars above about 20mm diameter are supplied in duplex grades to utilise the superior strength compared to austenitic grades. Bars are often coupled by screwed fittings or can be welded provided the heat tint is removed, preferably by pickling. It is essential that stainless rebar is protected during delivery and site storage. If adjacent carbon or galvanised steel requires cutting, the debris must not settle on the stainless steel. Figure 2 of four bars is for quality assurance of bar delivered after pickling to remove contamination and passivate the surface. The upper two bars have different levels of pickling but are acceptable. The lower two are not acceptable because of iron residue from the rinse water (C) and insufficient pickling time (D). Pre- and post-tensioned cables have been mainly austenitic but the strength advantages of duplex grades mean they are increasingly being used. Stainless steel mesh is often used to control shrinkage cracking and deliver tensile strength. A further product form for inclusion in concrete (and refractory) are wire fibres which are either undulating or with end hooks and aspect ratios in the range 35 to 60:1.
Galvanic acceleration of corrosion? Early on, there was significant resistance to specifying stainless steel due to the perception of the need for complete replacement of carbon steel. Connecting stainless steel to carbon steel corrodes the carbon steel but that assumes a near-neutral pH, i.e. about 7. Concrete is quite alkaline, i.e., pH>9.4, and in those conditions, the galvanic potential of carbon steel and stainless steel is about the same. Multiple laboratory and real-life tests have shown no galvanic acceleration of the carbon steel corrosion, even with quite significant levels of chloride contamination. Hence stainless steel can be used around joins in slabs, penetrations, at surfaces where diffusing water can evaporate and concentrate aggressive salts or where road or marine salts accumulate. The Schaffhausen Bridge in Switzerland used about 15 tonnes of stainless steel rebar in areas subject to road salt, about 5% of the total steel use. This added less than 1% to the capital cost and delivered a 13% life cycle cost advantage over simple carbon steel for an 80-year life cycle. Nearer to home, the McGee Bridge over the inlet in Hobart uses stainless steel rebar in the tidal zone (where the tides act as a chloride pump) and carbon steel in the superstructure where chloride risk is low. Misunderstanding of the chloride resistance of stainless vs. carbon steel The widely accepted chloride limits for common stainless steels in near-neutral water are not relevant to the highly alkaline interior of a concrete structure. Figure 1 shows the results of multiple laboratory tests and uses chloride as a percentage of cement as a measure of corrosivity. The limited use of carbon steel in poorly cast (higher chloride penetration) and lower cement content (lower pH) is evident. What is surprising is that austenitic 304 or 316 (or their “equivalent corrosion resistance” lean or low alloy duplex grades) provide useful service in a wide range of conditions. However, duplex grades provide double the 0.2% proof stress than their austenitic equivalent and the worldwide trend is to specify reinforcement at the higher end of the alloy grade strength.
FIGURE 1: R ange of chloride and pH for different alloys CHLORIDE CONTENT – % by cement weight
The unfounded barriers to using stainless steel
7
20oC
Super alloys – PRE >40 6 5
uplex 2205 d
4
16L 316/3
3
304/304L
2 1 0
Carbon steel
Phenolphthalein pH colour change 9
10
11
12
13
pH
FIGURE 2: Acceptable conditions for reinforcement ACCEPTABLE A
B
NOT ACCEPTABLE C
D
5 – Australian Stainless Issue 74
ARCHITECTURE
STAINLESS STEEL
Security, style, and functionality Stainless steel mesh has combined form and function in a patient-centred design to deliver a safe, outdoor sanctuary for recovering mental health patients. Ancient civilisations understood the critical importance of daylight associated with human health, happiness, and wellbeing. Today, there is increased interest in green architecture, with natural light and air becoming a significant design consideration. Studies suggest that light and nature should be strongly considered when building new medical facilities, because of their positive effects on recovery.
Manufactured and delivered by Crimsafe, the commercial strength screens are made from 0.9mm, grade 304 stainless steel wire and were fabricated in a multitude of off-square angles to seamlessly match the structure. Fabricating with stainless steel mesh allows for limitless flexibility to marry safety with style and functionality. The material can be shaped in multiple planes without compromising on strength, while its clean lines and obstruction-free form allows for creativity in design.
Austin Hospital in Melbourne’s north-eastern suburb of Heidelberg is a leading healthcare, teaching and research facility renowned for its specialist services in mental health and rehabilitation. A $15.2 million expansion of the hospital’s Short Stay Observation Unit and Psychiatric Assessment and Planning Unit in 2016 aimed to deliver dedicated mental health care to address the demand and growth of emergency department presentations.
All Crimsafe security screens are Australian made and meet or exceed the requirements for compliance with various Australian Standards. Crimsafe exceeds the 1.4 tonne requirement of AS/NZS 1170.2 (Structural design actions, Part 2: Wind actions) by three times the standard, load testing to 4.2 tonnes. In addition, the 1.5mm x 1.5mm aperture of the mesh filters up to 62% of UV radiation, minimising heat gains and delivering energy efficiency.
The Short Stay Observation Unit was built above the ambulance bay and includes a lounge that opens up to an outdoor space filtered with natural light, fresh air and unobstructed views. Crimsafe’s Tensile-Tuff® stainless steel security mesh screens were specified for the enclosed outdoor area balustrading as the ultimate solution for providing exceptional strength, transparency and multi-faceted safety and security properties. Tensile-Tuff® Crimsafe mesh does not compromise on visibility or airflow and is well-equipped to deliver on aesthetic appeal with the structure also being the main feature of the hospital’s external façade.
Forty-one bespoke triangular Crimsafe security screens were manufactured and installed by Sydney-based licensee, Wynstan. Crimsafe’s exclusive Screw-Clamp™ bites down on the mesh, holding it into the frame, which is then secured by tamper-resistant stainless steel screws. This vice-like grip transfers any weight and pressure to the frame, so the mesh remains intact. The unit specifically responds to the need for fall prevention, protecting patients and minimising falls.
6 – Australian Stainless Issue 74
With the help of stainless steel, Austin Hospital’s state-of-theart facilities exude strength, security and style, challenging the convention of mental health rehabilitation and recovery. Opened in 2018, the Short Stay Observation Unit continues to deliver a peaceful and safe space for patients.
DESIGN
Stainless steel water drainage
Australian innovation driving sustainability For over 30 years ASSDA Member Stormtech has been at the forefront of Australian innovation delivering stainless steel linear drainage solutions for the local and global architecture and design industries. Stormtech is an Australian family business that began operations in 1989 and was established on the invention of a special drainage grate. Founder John Creighton was approached by an architect to help design a hobless shower for a wheelchair-bound client wishing to shower independently. Creative thinking and innovative engineering led to the birth of a unique stainless steel drainage design that delivered excellent surface water removal efficiency while demarcating the wet and dry areas of a shower without a need for a hob or barrier. This design was adopted as standard, patented and is now Stormtech’s 65ARG slimline linear drain. Today Stormtech continues to thrive, pursuing innovation and excellence both in the way it operates and services its customers, as well as through its commitment to sustainability. A worldleading business in ethical and sustainable practice, Stormtech showcase over 150 drainage products across a range of many different functions, from bathroom, pool and spa drainage to hospitality, commercial, and healthcare applications. Their linear drainage products range in widths from 65 and 100mm and lengths from 900 -3000mm, with eight architectural grate designs on offer. Custom drainage products are also delivered for specific applications and water flow efficiencies. All Stormtech products are Australian designed and manufactured at their New South Wales’ facility in South Nowra. Stormtech prides itself in an all-Australian supply chain, with all stainless steel drains fabricated from grade 316. Electropolishing, electroplating and powder coating services are offered through their local network of third-party suppliers, to deliver specific stainless steel specifications requiring coloured and other special surface finishes.
tainless steel’s durability and sustainable properties S coupled with Stormtech’s quality design and manufacturing has assisted designers and specifiers meet their environmental goals. In addition, it has provided solutions to overcoming poor drainage issues in construction, including ponding, which can undermine foundations and lead to structural and aesthetic damage. As part of the company’s Industry 4.0 journey, significant capital investment has enabled Stormtech to introduce state-of-the-art manufacturing equipment and develop software automation for business and sales support. Their CNC machine processing and design and drafting capabilities have significantly increased, delivering positive outcomes including a 0.3% scrap rate. All materials are XRF scanned for grade confirmation and stainless steel scrap and offcuts are reused or recycled. Stormtech’s sustainable commitments have also seen the company pioneer their own stainless steel fabrication techniques to eliminate the use of harsh chemicals. Ongoing R&D will also see the company continue to launch and introduce new capabilities, with sustainability at the core of its focus. Stormtech was the first drainage business in Australia to gain sustainability credentials, maintaining its GreenRate Level A Gold certification with Global GreenTagTM since 2013. In addition, all products are WaterMark certified. .
. S tainless steel is a material of choice in linear drainage due to its strength, durability, low maintenance, safety, visual appeal and 100% recyclability. Grade 316 has excellent corrosion resistant properties, maximising product performance in coastal areas and pool installations, particularly where acidic soil may be present. Architecturally, stainless steel linear drainage offers an elegant and modern finish in addition to delivering a lower profile, creating an even, safe surface and seamless transition between indoor and outdoor areas. The material is also hygienic and easy to clean, complementing hospitality, health, and aged care applications.
Standard TR Grate design with custom curve Photo credit: Stormtech
ASSDA MEMBER CONTACT Stormtech \ Troy Creighton \ 1300 653 403 \ info@stormtech.com.au \ stormtech.com.au 7 – Australian Stainless Issue 74
PacRim Stainless 2022
20-21 July HOTEL X BRISBANE
Register now at: pacrimstainless-feb22.lilregie.com
A new era for Australian Manufacturing Brought to you by the Australian Stainless Steel Development Association (ASSDA), PacRim Stainless is the premier annual event bringing together Australia’s stainless steel industry and colleagues from abroad in an exclusive networking environment.
SPEAKERS Richard Matheson Director, Market Development Nickel Institute
PROGRAM OVERVIEW wo half-day conference sessions with an exceptional line-up of T speakers covering topics including: • Strategies to build industry resilience and drive local manufacture and production • Industry digitalisation and the future of manufacturing technology • Seizing market opportunities to grow the use of stainless steel • Raw materials and economic outlooks, including perspectives on global and local stainless steel market direction. Gala Dinner: Australian Industry Stainless Steel Fabricator Awards
Xu Aidong Chief Analyst, Beijing Antaike Information Co., Ltd Peter Munckton Chief Economist, Bank of Queensland
ASSDA Young Professionals Network launch
CONFERENCE SPONSORS:
pacrimstainless.com
PLATINUM MEMBERS:
GOLD MEMBERS:
SILVER MEMBERS:
Stanch Stainless Steel Co., Ltd.
Acerinox \ Amity Pacific \ Aqseptence Group \ Arcus Wire Group \ AusPress MEI \ Austral Wright Metals \ Australian Stainless Distributors \ Callidus Welding Solutions \ Ching-Hann Industries Co., Ltd. \ Dalsteel Metals \ Fagersta Steels \ Metal Centre Australia \ Prochem Pipeline Products \ Sanwa \ Stainless Steel Wire & Mesh \ Vulcan Stainless \ Yue-Seng Industrial Co., Ltd.
Stoddart YC Inox Co., Ltd.
AUSTRALIAN STAINLESS MAGAZINE MORE INFO: Enquiries or further information on any material presented in this publication should be directed to ASSDA: Level 6, 200 Adelaide St, Brisbane Qld 4000 \ +61 7 3220 0722 \ assda@assda.asn.au \ assda.asn.au EDITORIAL: Contributions of story ideas specialising in stainless steel and its applications are welcome from Members of ASSDA. ADVERTISING: Advertise in the only publication that reaches a targeted group of 5000+ in the Australian stainless steel industry. Rates available at www.assda.asn.au. CONTACT: Lissel Pilcher, Editor: lissel@assda.asn.au DISCLAIMER: ASSDA sources articles and advertisements from a variety of contributors and accordingly does not accept responsibility for the accuracy of the contents of this publication nor the suitability of specific applications referred to herein for any particular use. Competent advice should be sought before acting on any matter contained in this publication.