Green concrete

When it comes to concrete, the Pantheon in Rome may be a perfect model for long-lasting green technology. LEED-status buildings are using its ancient wisdom in modern structures. The 2,000-year old-structure’s greenness is twofold.  First, if a building is designed to last for thousands of years, it will. Because it will only be built once and (hopefully) not require major repairs, it’s already by definition a sustainable building.

Most concrete buildings are merely built to be functional for the moment – even structures you’d expect and want to last longer.  For example, according to civil engineer John A. Bickley, even nuclear reactors are only built to last for about 120 years.

That’s not to say all concrete buildings are about to topple; Bickley’s tests indicate the CN Tower probably won’t break down for 1,000 years.  But what will help more concrete last?  The Pantheon’s second secret: volcanic ash.  Not as a filler agent, but a binding aid. Volcanic ash makes concrete more durable.

Using waste products – such as ash – is an innovation that modern builders are using to increase concrete longevity, and also to reduce overall carbon footprint. Using slag, silica fume and fly ash in the mix, greatly reduces the amount of CO2 produced.

These mixes are more than just environmentally friendly, but much more durable. They use up waste products and turn them into something useful and beneficial.

It made sense 2,000 years ago, and it makes sense now.  After all, “when in Rome…”