The Strength of Concrete

Mark Miodownik explains our planets dependence on concrete in his book, Stuff Matters, which is an exploration of the built world and the materials that make the world what we see.  Miodownik explains that the first concrete developed on our planet came from the Romans, but the technology was not perfected until more recent times.  He also tells the story of how reinforced concrete came to be when a potter found that he could produce cheap concrete pots and boost their durability by setting the concrete around a steel internal skeleton. The strength provided allowed his pots to hold up to dropping, shipping, and the general wear and tear of the gardening world.
I find Miodownik’s section on concrete fascinating. Prior to reading his book I had never stopped to consider what truly went into producing concrete and concrete structures.  from our sidewalks, to buildings, to dams and barriers, we see concrete everywhere and Miodownik reflects on our perceptions when we see things everywhere.  He writes about our normal tendency to see those common and everyday things as simple and unimportant, when oftentimes, as in concrete, they are complex, crucial, world altering innovations.
While most of us may not appreciate just how important concrete is and we may not understand just how complex concrete is, there is an understanding in our country that our infrastructure needs some TLC.  And it is not just people in the United States who know their structures need some love, “To prevent stone or concrete structures being similarly affected, maintenance of their fabric needs to be carried or every fifty years or so.” In this quote Miodownik is explaining the effect of general wear and tear on concrete.  As materials heat up or cool down, as happens yearly due to the temperature changes of the seasons and days, they expand and contract. Reinforced concrete is a wonderful material in respect to contraction and expansion because the concrete itself and the internal steel skeleton expand and contract at almost identical rates.  This prevents the steel from busting out of the concrete and keeps the steel protected and the concrete free from cracks.  But overtime the concrete does develop micro-fractures, which grow into visible fractures, which allow more water in, and become clear chips and breaks in the concrete.  This erodes and breaks down the concrete structures we build in the same way that nature breaks down the mountains around us (or at least around me living in Reno Nevada at the base of the Sierra Nevada Mountains).
I think what I like about Miodowniks quote is that it shows the impermanence of what feels like our most robust building materials.  We may look at concrete structures and imaging their hulking frames will last forever, but what material science shows us is that they are constantly in a battle to be broken down. Even the mountains which define borders and seem to be natural strongholds of the earth are not permanent as weather batters them down.  If you cannot enjoy the science behind the concrete, hopefully you can at least appreciate the brevity of its existence in the long term life of the planet, or appreciate our perspective on the material, seeing it as an unyielding monolith which ultimately is brought down by some water and wind.

Material Science

In his book Stuff Matters Mark Miodownik explores the world of every day materials that shape our lives and understandings of the world.  He looks at steel, concrete, foam, and more to show us how complex our seemingly simple world is.  He continually reveals the misconceptions people have about the materials in our daily world by telling the backstory of materials and presenting them in an almost lifelike manner.  Miodownik writes, “materials are not static things: they respond to their environment, and especially to temperature.”

 

I think Miodownik’s quote is a great one for people outside of the general science or material science community because it begins to reveal and explain the complex nature of the built world.  We often are appalled when systems fail (think of a train wreck, the BP oil spill, or crumbling concrete infrastructure) but few of us understand just how those systems operate and what forces limit or strain our engineering.  It is easy to criticize a company or government when materials are not holding up to our demands, but simple criticism ignores the fact that our products face factors and variables that are sometimes impossible to know or predict.  Through science and testing we can develop systems that are more secure and sound, but we will never be able to account for 100% of the anomalies that any given bridge, airplane, or coffee table will face.

 

I recently read Joel Achenbach’s recount of the BP Deep Water Horizon Oil Spill A Hole at the Bottom of the Sea, and throughout his book he highlights the fact that our engineered planet has become so complex that it is nearly impossible for the average citizen (or even the President of the United States) to truly understand how everything is organized. What I have taken away from these two books is that we need to be more patient with the world around us. We can hold engineers, car companies, and manufacturers to very high standards, but we should also expect and be prepared for systems to fail.  Oftentimes a failure in our built world is not the result of a single overlooked, poorly built, or sloppily assembled unit, but rather the result of anomalous strains and individually inconsequential shortfalls.  Developing a better understanding of the built world around us will help us react and respond better to our materials and their potential failures.  The more we know about science and the current state of science the more likely we are to support development, and when things go wrong, the less likely we are to point fingers as opposed to aid the development of novel solutions.