Matsuo Corp's "Eco-Paver", Water Retentive Blocks
by John Laumer, Philadelphia on 10.12.05
The "Eco-Paver" concrete slab is made from recycled construction materials, specially cast to wick up water, through capillary action, and perform a landscaping device-mimic of plant transpiration. Widespread deployment in a city or region would help urban areas adapt to climate change, mitigating against the "heat island" effect through evaporative cooling. From the The Yomiuri Shimbun of October 10'th: Ecopaver... "uses recycled waste materials such as concrete, asphalt and the incinerated ash of urban garbage; it saves energy by reducing the need for air-conditioning; and it contributes to the development of a recycling-oriented society".
Because the market is public works projects, the desired effect is proportional to government giving the product a leg up over traditional paver bricks. With US style governance, that'll never happen of course (except perhaps in Chicago). Ooops, almost forgot that the freeze/thaw effect will limit Eco-Pavers to southern climes. Perhaps a gated community called "Noah's Ark"?
A few more excerpts from Yomiuri Shimbun follow, attributed to Hitoshi Nishiwake, Matsuo Corporation's President. "We knead a thick concrete in a mixer, put it into molds, press and vibrate it into shape and then remove it from the molds quickly. The entire process--called vibration concrete molding--is done automatically by machine..." "As our concrete is thick, water-retaining voids remain in the finished product," he said..."According to the size of voids, the blocks become either water-permeable or water-retentive".
"Water-retentive blocks are as strong as ordinary blocks and strong enough to bear the weight of vehicles. They can be used anywhere. And with their capacity for retaining water, they can be used as vegetation blocks, too."
He said: "We've worked with used and recycled materials for a long time. I personally inherited the spirit of "mottainai" [literally: "It's a shame to waste things."] from my ancestors. As global warming progresses, we'll take a natural approach to conserve the global environment and continue contributing to it company-wide in the future."
If they're retaining water does that mean they're moody too? :D
I don't know much about concrete, but I think I've heard of their method before. It was called "making bad concrete that won't take much stress and break". When they make durable concrete structures they get all the air bubbles out because they weaken the block. If I'm wrong here, please enlighten me.
Tim, it's not really possible to say whether you're right or wrong here because 'concrete' is a very general term, kind of like the word 'cake': there are a lot of recipes for concrete. The wikipedia entry on concrete makes some mention of plasticizing additives to reduce the need to vibrate concrete to remove air bubbles, and I have a hunch that there are lots of other strange things people do to make concretes with various special properties. Some people even use specially formulated concrete to make canoes! So while you're certainly right that some concrete needs to have air bubbles removed to achieve good strength, that may not be the case with this particular concrete that Matsuo Corp is making.
It is possible to say. The linked article states that their water permeable bricks were only 60% of the strength of regular pavers, but the retentive bricks (the ones mentioned here) were virtually identical in strength to normal bricks.
That's the newsworthy item. Any fool can make spongy bricks (indeed, it is easier for a fool than a wise man), but these folks have spent a lot of R&D time working out how to make them strong, and use waste products to do it.
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You guys are team! Checks and balances. Fast take and slow read. Put it together and you get a chain reaction. Now how do we get a US culture that looks out for the commons like this company did.
Pervious concrete has been around for along time. This just looks like another method to realize pervious concrete pavers.
I personally like BIOPAVERs for SWM... read about them at http://www.biopaver.com