I was initially sceptical, but these ideas seem like genuinely sensible uses for old turbine blades. The bus shelter in particular seems rather appealing.
I'm reminded of the use of crumb rubber from recycled tyres as a paving material. Rubberised asphalt is an excellent material for many applications, but would be largely uneconomic without the supply of very inexpensive rubber from discarded tyres. These structures made from repurposed turbine blades may not be ideal, but they may make a great deal of sense if the raw material is basically free.
Isn't there some concern over the chemicals which can leach out into the environ from recycled tires (crumb rubber) Concerns over impact on human health. Or is that concern misplaced?
You're not eating the rubber and by the time the tires have made their way to recycling I would expect basically all the volatiles would have offgased. The MSDS [1] would suggest the biggest risk is breathing the fumes caused by burning or rubbing the crumbs in your eyes and scratching your cornea. While there are trace amounts of naphthalene, I imagine its more an issue for those involved in the manufacture than those people playing on a playground padded with it.
I thinks it's too early to tell if there is or isn't a danger. Preliminary studies in controlled environs have not found cause for much concern, but others are calling for more rigorous examination. Personally I dont think there has been enough research taking into account people playing multiple hours a day on these surfaces, so id rather see more studies into exposure.
It all seems rather desperate to me and unimaginative (children will love climbing over it!). This is not a structural way of disposing of these blades, it's a public relations effort.
The solution of using old rotor blades as structural material seems not badly suited to the scale of the problem. The global market for cheap lightweight and strong structural elements is far larger than the amount of rotor blades needing recycled. Just working out a nice design for an agricultural barn would probably cover it.
Also, modification for re-use is generally far less energy intensive than full recycling, even if it were currently available.
> Although, David Hertz Architects did find out that the studio has to register the roof of the house with the FAA (Federal Aviation Administration) so pilots flying overhead do not mistake it as a downed aircraft.
Materials are not good or bad in itself, they have just different properties that are weighted by the 'architect' when choosing a material:
- some more objective (resistance, durability, toxicity, etc)
- some more subjective (costs, fashionability, desirability, commissions.., etc)
In this specific case, the material was imposed, changing the 'game': material comes first than the function and reaching an optimal solution is normally more difficult. Optimal solutions are almost never obvious and while there isn't one, 'architects' use some temporary/obvious solutions like this one.
What constitutes true creativity is the openness and adaptability of our spirit - Robert Green
Can these blades not be shredded and chopped up, and the resulting fibers used in less-critical parts, like aftermarket auto hoods, swimming pools, etc? Using a process like the fiberglass spray lay-up, with a chopper gun.
Not a materials person, but wouldn't shredding and chopping leave you with small fragments of fibers encased in resin. Fiber length is important to the strength, and I'm not sure how well new resin would bond with cured resin. I'd think the result would be much, much weaker.
Chopped mat fibers would also defeat the purpose of carbon fiber in aftermarket auto parts, which is to be pretty.
> so why is their service life so much shorter than some planes have had?
The lifespan is typically 20 years unless there is a catastrophic failure (huricane, typhoon, manufacturing error, etc). There are some major differences in how turbine blades and airplane wings behave:
- A wind turbine blade suffers gravitational, centrifugal and aerodynamic loads about 10 times per minute, 2500h - 3000h/year. These forces can be up to 20kN[0]. (vs. plane only accelerates for take-off and landing very few times a day, and is otherwise is a relatively steady load regime)
- Wind turbines are often in remote locations, and maintenance can't happen every time they come to an airport (predictive diagnostics by embedding sensors in the blades is starting to change this)
Generally, fibre reinforced polymers are great materials for the job and there are a variety of applications for the recycled fibres (filling for new blades, downcycling, architecture, etc [1])
I'm confused. Why do you think that planes have a longer lifespan?
I mean, I assume we're talking about plane propellers here, right? Not airframes or something? Are you sure that a plane would fly with the same blades for more than the cited 10-25 years?
I'd also be a bit skeptical about their structural integrity. Composites usually have dimensional strength with weaves going in orthogonal and diagonal to each other. However, any holes, or stress cracks would make their recycled use for less critical applications. I would like to read further on how they inspect and possibly recondition them for less stressful use, but within the parameter of re-purposed, safe use.
It's been a while, but I used to work with some folks who performed maintenance on helicopters that had composite rotor blades - and they were constantly being inspected and sent back to the manufacturer.
Perhaps it's different in the civilian aerospace world, but I don't think it's sensible to expect those blades to last as long as the airframe.
The lifetime of composite rotor blades is shorter than metal based rotor blades that were used in older generations of helicopters.
Example:
The B0 105 helicopter is cleared for up to 3.5 positive G force and one negative. Its agility and responsiveness can be partly attributed to its rigid rotor blade design, a feature uncommon on competing helicopters.
The rotor system is entirely hingeless, the rotor head consisting of a solid titanium block to which the four blades are bolted; the flexibility of the rotor blades works to absorb movements typically necessitating hinges in most helicopter rotor designs. The reliability of the advanced rotor system is that, in over six million operating hours across the fleet, there had been a total of zero failures. One benefit of the Bo 105's handling and control style is superior takeoff performance, including significant resistance to catastrophic dynamic rollover; a combination of weight and the twin-engined configuration enables a rapid ascent in a performance takeoff.
The MBB Bo 105 is the only heli cleared for acrobatic stunt flight and is the work horse of "Flying Bulls" (Red Bull).
That's like a new kind of LEGO for grownups. Someone should try to make a game where you can reuse such pieces, carve them, and then place them on top of existing google/bing/other maps.
I'm reminded of the use of crumb rubber from recycled tyres as a paving material. Rubberised asphalt is an excellent material for many applications, but would be largely uneconomic without the supply of very inexpensive rubber from discarded tyres. These structures made from repurposed turbine blades may not be ideal, but they may make a great deal of sense if the raw material is basically free.