Friday, 9 February 2018

Book review: Concrete and Culture, Adrian Forty (2012)

Subtitled, ‘A material history’, this book goes more of the way I needed to learn about the emergence of concrete as a construction material in the 19th and 20th centuries. From the 1890s, when different systems for using reinforced concrete were first patented, until the 1950s when, after WWII, there was a building boom as a result of decades of depressed demand, the use of concrete gained traction. The Depression and the war had taken business focus away from building high, which is expensive.

I first found out about Forty’s book at the University of Sydney library when I went up there to look for books on concrete, and I then bought it to use on the Kindle. I had already read one book on Brutalism, which I reviewed last month.

Forty looks at concrete through a variety of lenses, including the cultural, and he is an architectural historian so he is familiar with the technologies involved in the material’s use. Readers of the book should be prepared to go looking up words online, as I did, when unfamiliar ones appear.

The use of reinforced concrete began first in Europe and it wasn’t until the end of WWII that the Americans started to use it with any frequency. Before that, American building designers had made buildings with steel frames, but steel is easily damaged by high temperatures, so steel buildings distort and buckle if there is a fire. With reinforced concrete, the steel is encased in concrete, which inhibits the effects of fire.

Heating, ventilation and air-conditioning systems started to appear at the turn of the 20th century. Electric lifts had first been used twenty years earlier. Fluorescent lighting became cheaply available not until the end of WWII. Pre-stressing techniques were invented in the interwar years of the 20th century, and started to be used in construction more widely in the 1940s.

Forty examines concrete as an aesthetic medium as well as a technical device for achieving certain construction outcomes. There have been so many different attitudes toward concrete but what is clear is that it will continue to be heavily used for construction around the world, even though it is energy-intensive to make so it has a heavy carbon footprint. Concrete is partly made up of cement, which is itself made from clay and limestone heated to a temperature of 1450 degrees Celsius in a kiln, which produces clinker, a substance that is ground into a powder before used to make concrete. Concrete is a mixture of cement, gravel, sand and water.

One point that Forty makes well is that even though for most people concrete remains a potent indicator of modernity because of the way it enables the construction of very tall multi-storey buildings, its use is actually very craft-like in nature, although relatively inexperienced people can effectively use it to build. The finish of concrete depends very much on the skill of the people involved in the construction process. The formwork (called “shuttering”) that is made of wood or steel to contain the still-liquid concrete before it hardens, can be beautifully done or it can be less perfectly realised. To eliminate bubbles in walls, the formwork has to be gently vibrated, but not too much otherwise the aggregates used in the concrete mix will pool at the bottom of the formwork.

In some parts of the world, where cost is a major factor for people who build houses, concrete can be used by ordinary people with few tools other than a bucket, a spade and a wheelbarrow. 

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