(Image courtesy Army Corps of Engineers.)

To register once more our fascination with testing grounds, or sites of experimentation and simulations, here is the rack map of concrete slabs at the U.S. Army Corps of Engineers' materials testing facility at Treat Island, Maine.

On the island, material specimens are exposed to natural severe environmental conditions to test for durability. They are subjected to between 100 and 160 freeze-thaw cycles, cyclic inundation of saltwater and air-drying, chloride intrusion, wetting and drying, and abrasion-erosion. There and in many other testing grounds, arranged in museological, Donald Judd-like intervals of solids and negatives, these perfect geometries are coming undone. The building blocks of future cities and monuments fracture and decay in a way that belies their solidity and intended permanence. Bit by bit, atom by atom, structures get nullified and give way.