Junttan develops safe, smokeless pile cushion technology
Junttan recently launched a new environmentally sustainable technological solution as an alternative to conventional wooden pile cushions that eliminates the occupational health issue of smoke. Made out of recycled plastic, Junttan’s J-Pad material lasts up to 10 times longer than wooden cushions and doesn’t generate smoke or heat compared to wood.
“The project resulting in J-Pad started about four years ago stemming from the desire to get rid of the problem of smoke related to piling work in reinforced concrete piling,” said Jaakko Rytkönen, a service development specialist with Junttan. “It was a work safety issue, an occupational health issue and a work comfort issue.”
Traditional wooden pile cushions, usually made of hardwood and plywood, generate heat and smoke when piling, creating smoke-related vapors, gases and microparticles at the work site and the surrounding area. On top of hindering visibility on the worksite, the use of wooden cushions can cause short- and long-term health issues.
In addition to eliminating smoke, J-Pad provides stable and optimal efficiency of the energy transfer from the hammer to the pile. Another perk is that J-Pad makes it easy to change the cushion.
“It doesn’t have to be taken off from the pile housing because if the piling event heats the cushion enough, it melts off from the drive cap at which point the operators just have to add a new plate to the pile helmet of the drive cap,” said Rytkönen.
Developed to be used in reinforced concrete piling, J-Pad can be used in most concrete piling jobs for all pile shapes. To date, J-Pad has been used with pile sizes between 200 mm and 400 mm, both round and square.
A healthier solution for workers that also performs better
Although J-Pad was a solution designed to increase worker safety and comfort, it also offers more stability and durability. During research and development, Junttan’s main objective was to find optimal material that would offer durability during piling work and wouldn’t ignite easily.
Reinforced concrete piles require some cushioning between the hammer drive cap and the pile. The cushioning protects the pile from being damaged during direct contact with hammer drive cap.
“Traditional wooden pile cushions start to deteriorate soon after the piling work has been initiated due to the kinetic energy transferred to the pile being converted partially to heat energy,” said Rytkönen. “This leads to thermal degradation of wood. Heat soon starts to increase the internal pressure of the wooden pile cushion through release of water vapour and pyrolysis-induced gas build up in the wood material.”
J-Pad is durable and can withstand the stress of pile driving hammer blows. Unlike wooden cushions, J-Pad retains its cushioning effect and bulk modulus of elasticity throughout the entire service temperature. By employing J-Pads as a pile cushion, a stable output and solid results can be consistently achieved.
Wooden pile cushions heat during piling work and can exceed temperatures of 200°C, which is considered to be the hot work threshold in many countries.
“Ignoring these temperature limits creates risks in working safely and increases the likelihood of insurance risks due to fire damage,” said Rytkönen. “This is especially important when piling in job sites that are sensitive to fire such as refineries and chemical plants. J-Pad does not emit combustible gases and does not heat during the piling work so that it could be set afire.”
In addition to being non-combustible, the material is antistatic and contains a significant portion of recycled materials. J-Pad is fully recyclable in the plastic recycling process or it can be used as energy waste if plastic recycling is not available.
A major benefit for projects using precast concrete piles is that J-Pad can withstand extreme temperatures and all kinds of weather conditions such as rain, snow, sleet and heat. The non-water-soluble material is easily stored and doesn’t absorb moisture like wood.
In Canada, sales and distribution is handled by Junttan’s local dealer, Canadian Pile Driving Equipment. Junttan can be contacted directly to help determine the sizing for jobs and to provide technical support.
Editor’s note: The views and information in this article are not to be construed as an opinion of Piling Canada magazine or Lester Communications Inc. 