Bridging The Gap Between Dissimilar Road Types With Foam

When you think of driving up or down an embankment, do you ever wonder how much foam you’re currently driving on? Probably not, because it hardly seems like a suitable building material. But as explained by [Practical Engineering] in the video below the break, using an expanded material to backfill an embankment isn’t as dense as it sounds.

In many different disciplines, mating dissimilar materials can be difficult: Stretchy to Firm; Soft to Hard; Light to Heavy. It’s that last one, Light to Heavy, that is a difficult match for roadways. A bridge may be set down in bedrock, but the embankments approaching it won’t be. The result? Over time, embankment settles lower than the bridge does, causing distress for cars and motorists alike. What’s the solution?

To mitigate this, engineers have started to employ less dirty materials to build their otherwise soil based embankments. Lightweight concrete is one solution, but another is Expanded Polystyrene (EPS) foam. Its light weight makes installation simple in anything but a strong breeze, and it’s inexpensive and durable. When used properly, it can last many years and provide a stable embankment that won’t settle as far or as quickly as one made of dirt. Because as it turns out, dirt is heavy. Who knew?

Aside from roadways and bespoke aircraft, EPS foam has also been used for making home insulation. What’s your favorite use for EPS foam? Let us know in the comments below.

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Whirling Sawblades Turn Foam Packaging Into Wall Insulation

If you’re like us, the expanded polystyrene (EPS) foam inserts that protect many packages these days are a source of mixed feeling. On the one hand, we’re glad that stuff arrives intact thanks to the molded foam inserts. But it seems so wasteful, especially when chucking it in the garbage can. If only it could be effectively recycled.

It turns out that it can be, if you equip yourself with this spinning “sawblades of doom” EPS recycler. It comes by way of [HowToLou], who was looking for a way to insulate a wall on the cheap. Almost all commercially available insulating materials – fiberglass batts, blown-in cellulose, expanding polyisocyanurate – are pretty pricey. Foam packing pieces are pretty easy to come by, though, and usually free for the taking. [Lou]’s method of turning them into insulation is a box containing four circular saw blades mounted to a piece of threaded rod and spun by a cordless drill. The blades are mounted askew on the rod for better reduction of the foam; [Lou] chose to use wire to hold the blades down, while we’d have printed up some slanted arbors and bolted the blades down more firmly. A chicken wire prefilter keeps the big chunks from clogging a blower made from an old bathroom exhaust fan, which does a great job of filling the wall cavities with pulverized EPS nuggets. The video below has all the details.

Honestly, the box is a little scary, and we have doubts that [Lou] will be able to get enough foam to finish the job, but it’s still a clever little hack. Grinding things up seems to be a theme for him; check out his leaf collector or his apple cider press.

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