Public: Engineering
Seeds of Destruction   (+24, -1)  [vote for, against]

These are grass seeds, coated in plastic. Mix them in concrete, pour a pad, construct a building over it, and nothing happens. Not until years later, when Wal-Mart has gone to the other side of town, leaving only that unsightly and indestructible pad. A year or two of exposure to rain, and the polymer softens; the seeds begin to absorb water. They begin to grow, developing hydrostatic pressure, pushing against the concrete. A web of almost invisible cracks form in the surface, and more water seeps in. It’s an accelerating process. Within months, the once monolithic structure is reduced to gravel, covered with tall fescue.
-- ldischler, Mar 27 2005

A fine idea. However, why not do this with crop seeds? In the event that society collapses, periodically some maize or okra will spring forth from the decaying rubble. Our degenerate descendants, clad in foraged 2-liter pop bottles and their own blue mutant fur, will find these precious gifts, cultivate them, and begin civilization anew.
-- bungston, Jul 10 2006

Such an interesting idea: impregnate the cement in concrete with the seminal (eco-systemal/prodigal) energy to quickly reclaim the failed land-grabbing ventures (business or otherwise) of those arrogant Homo Sapien bastards! Cool... (I hate them!)

But ... what is your polymer/plastic coating that just "softens" (bio-degradable plastics are mostly phony: they just add cellulose); and WHY are these seeds not just destroyed by the natural compression from the self-compacting concrete as it settles (read: dehydrates); and, even worse, the exothermic heat involved? (Calcium oxide into calcium hydroxide.)

Contigent: [-] until I know...
-- Wily Peyote, Jan 07 2009

sp. "cogent"
-- coprocephalous, Jan 07 2009

[marked-for-self-deletion] OK, you got me! But I got you too: the word should be "contiNgent", not cogent.

I guess the spelling-cop [rocephalous] is human after all! Sad day... (And [normzone] wanted to install you as a spell-check button...)
-- Wily Peyote, Jan 07 2009

<smacks forehead> "contiNgent"! How /could/ I be so stupid? </sf>
-- coprocephalous, Jan 07 2009

Are you taking the you-know-what, [IT]?
-- coprocephalous, Jan 07 2009

random, halfbakery