Ageing Concrete

Concrete rubble breakwall

A ten minute bike ride from my studio there is a concrete breakwall that keeps Georgian Bay waves away from a small boat launch. This blog isn't about concrete construction, but the surfaces of these huge blocks made me rethink how I see concrete.

When concrete is formed and when it sets, it looks like concrete. There is no mistaking it for another material, although some sculptors change the surface to make it look more like stone. Some even use metallic pigments to make it look like metal. But it is what it is and from my point of view, that's the way it should be. Concrete is a simple and honest material. Leave it alone. Look at Tadao Ando's concrete to see what I mean.

But I think my opinions are changing. Seeing these massive broken concrete slabs above and below the water made me realize that what you are actually making is a kind of stone. Portland cement, the "glue" in concrete, is made by super-heating limestone or chalk to release the water that is chemically combined in it, and when water is added back to it it actually becomes a stone once again binding other aggregates together. These old blocks at the water's edge now have surfaces rich with lichens, mosses and even small growing plants -- just like the natural limestone outcroppings in this area. The edges are worn from being moved around, some have cracked from ice and frost damage. They have a history, like the glacier-moved boulders we see in farmer's fields in Southern Ontario, only these old concrete slabs have their surfaces marked by people, machinery, and a shorter time span. Concrete is a man-made material, but give it enough time and it becomes more and more like what it came from.