The aim is to find out whether the durability of concrete can be improved by adding organic polymers. Can we learn something from the tricks of the ancient Romans?
Background
Many modern buildings only have a short lifespan. Whether bridges, motorways, railway sleepers or paving slabs - they often fall apart after just a few decades. A variety of reasons are usually given for this: Incorrect admixtures lead to so-called concrete cancer, which causes carriageways and sleepers made of reinforced concrete to crack; bridges are not designed for today's traffic with heavy lorries, the vibrations of which lead to cracks; penetrating water and brine lead to corrosion damage to the reinforcement, which affects the strength of concrete structures. But even the lawn edging blocks in my garden have become crumbly after forty years, even though they were neither exposed to lorries driving over them nor to any other stress worth mentioning, but simply had to withstand wind and weather.
The ancient Romans already used the most important component of concrete as a building material: quicklime. It is remarkable, that bridges and buildings from Roman times are still standing after almost two thousand years. Why did the ancient builders achieve what today's civil engineers fail to do? One might argue that ancient buildings were often built much more stable than absolutely necessary because static calculations were still unknown in past times. Beyond that, roman bridges have never been exposed to lorry traffic, which is said to be the main reason for the short lifespan of modern bridges.
But perhaps there is another reason for the long lifespan of old buildings: the Romans mixed their mortar not only from quicklime, sand and water, but also added eggs, curd or cow's blood. This practice continued into the Middle Ages in the construction of churches. The use of food as a building material is surprising at first glance - hunger was widespread at former times and animal products such as eggs and milk in particular were scarce. Without good reason, precious foodstuffs would not have been used in large quantities as a building material. Of course, the production of quicklime was as energy-intensive and quite expensive, but a sufficient supply of food has always been more essential. I can therefore only think of one sensible reason why food was mixed into the mortar: Adding them improves the properties of mortar. We know the effect from baking: eggs, milk and curd are excellent binding agents. I also suspect that added organic polymers can absorb stresses that would otherwise lead to microscopically fine cracks in building materials.
Feasibility
The aim is to test whether the addition of eggs, curd or organic waste from food processing improves the durability of building materials containing cement. The necessary test stands are available at every well-equipped technical university.
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