Eastlink Project and the Boss SpineSeal^®

EastLink is a tolled 40km road network connecting Melbourne’s Eastern and South-Eastern suburbs. Opened on the 29th of June 2008, EastLink became Australia's largest road infrastructure project costing approximately $2.5 billion. The construction of the Eastlink project was a joint venture between Australian construction companies Thiess and John Holland, SICE and United Group Infrastructure.
EastLink was designed with several architectural art pieces, including 7,500 brightly coloured acrylic noise barrier panels rising over the hills and bridges of the freeway. Boss Polymer won the tender to supply Thiess John Holland with 50,000 lineal metres of Ozone and UV resistant EPDM rubber gaskets to be installed between the acrylic panels to secure, insulate and weatherise them.
Along with the acrylic panels, cantilevered concrete sound barrier panels also line both sides of the roadway for much of the freeway’s length. These cantilevered concrete sound barriers were installed using traditional caulking materials and common compression seals. These methods required skilled personnel working in suitable weather conditions to build up layers of caulking compound to fill wide and uneven gaps in a vertical plane. This antiquated method produces a lot of rubbish on site.

The challenge presented to the Boss Polymer team was to produce a 30 year weather resistant seal that could be installed quickly, cleanly, and in any weather conditions. The solution was the Boss SpineSeal^®, a unique expansion and control joint seal system for gaps in vertical, horizontal and overhead structures. The Boss SpineSeal^® delivered faster installation times, high performance weather and sound insulation and reduced environmental and OH&S impact.

The key to the SpineSeal^® design is an extruded rubber fin shaped seal, which is folded over a rigid backbone and then driven into the gap. The rigid polymer backbone forces the SpineSeal^® into the gap and the “fins” on the rubber seal provide several layers of weather and sound barriers. In addition, a range of architectural exterior finishes and colours can be compounded and permanently moulded into the SpineSeal®. This allows the architect or designer to tailor the seal design and its exterior appearance to suit the application.

The Boss SpineSeal^® solution was achieved through collaborative work by the Thiess John Holland engineers and the Boss Polymer Technologies team. Thiess John Holland Noise Barrier Manager, Paul Belcourt said that “the enthusiasm and dedication of the Boss product development team helped to achieve acceptance of the concept. The SpineSeal® proved to be more effective than caulking, especially in the wider gaps. SpineSeal^® can be installed even if panels are wet. Quicker installation meant money saved.”
The Boss SpineSeal^® offers many advantages over traditional caulking methods including:

• Easy application – the light-weight SpineSeal^® can be easily installed by one man. Working from a boom lift, the installer can use simple mallet and press hand tools to ensure perfect fit with no variations
• Faster installation – each seal is installed uniformly in a single piece in minutes in any weather conditions
• Safer and cleaner to install – improves OH&S and environmental performance by eliminating adhesives, chemicals, caulking, and their dirty containers and messy clean up
• No preparatory work – the SpineSeal design allows for a wide range of variations in:
  • The manufacture of the concrete panel (rough gap edge surface condition)
  • Panel installation gap widths (ranging from 5mm to 80mm on the EastLink project)
• Excellent sound and weather insulation – each “fin” in the SpineSeal^® provides an extra layer of air lock and sound barrier
• Flexibility and retainability – the SpineSeal^® adjusts to gap variations caused by expansion, contraction or subsidence of the concrete panels, while remaining locked in place due to the multiple fins on either side of the rigid backbone
• Long life – the elastomer can be engineered specifically for the climatic exposure predicted for each application, including high UV levels, moist or dry conditions
• Aesthetically appealing – the elastomer can be engineered in any colour required to match / contrast with the concrete panel, and surface designs can be applied
• Does not require skilled labour - SpineSeal® can be installed following a simple, short training session
• Quality control – the SpineSeal^® design and ease of installation allows for easy pre and post installation quality control auditing
• Lower costs – the boss SpineSeal^® is easier, faster and cleaner to install in any weather conditions, therefore reducing installation time and costs

Thiess John Holland Project Engineer Frank Kose said that productivity increased significantly with up to 200 lineal metres of seal installed in nine working hours with a two man crew. Mr Kose stated that “using the SpineSeal, minimised general construction rubbish on site, such as plastic caulking tubes,” he went on to state that SpineSeal^® “is user friendly and less messy for the applicators to use. It adapts to the gaps size and shape and its consistent nature minimises seal quality issues. We have certainty that once installed, it satisfies design requirements and that simplifies quality control.”
Norman Mills, Managing Director of Boss Polymer Technologies stated that the SpineSeal^® can be extruded in a wide range of polymers and sizes to tailor the performance and aesthetic requirements to each application, “the silicone rubber used in the EastLink application is UV, heat, ozone and weathering resistant and was proven in industrial tests, including climate DIN50018-SW2.0S and ozone DIN53509-1. Even after 30 years or more exposure, there is virtually no change in the properties of the silicone seal.”
In addition to the initial use of the Boss SpineSeal^® in concrete panels, Norman Mills envisages a wide range of applications for the product in the construction of roads and commercial buildings, including filling gaps in overhead panels, which are difficult and costly to seal with traditional methods.