ON SUSHI, ORANGE PEEL AND SELF-HEALING CONCRETE

INSPIRATION 1: LOOKING BACK AT JAPAN’S EDO ERA

Time and again, there have been periods in the past in which societies have had to be especially frugal with their resources – usually because of crises. The sacrifice involved often leads to creative solutions and interesting products, as a look at Japanese history shows.

The Edo period represented a cultural heyday of Japanese culture and took its name from the city of Edo, today’s Tokyo. During this period from the 17th to the 19th century, Japanese society lived relatively isolated from the rest of the world. The fact that only a limited number of local raw materials were available for use at the time led to resources being handled creatively.

Wood was a scarce commodity back then. People were not allowed to cut down trees and were only permitted to collect wood – though no more than each collector could himself carry. The shortage of firewood led to the idea of cooking just one large portion of rice a week and creating a dish of cold rice and raw fish – and so sushi was born.

Fabrics and clothing were in equally short supply. This gave rise to the idea of sewing a garment from a single length of fabric, which could be re-sewn and adjusted several times over the course of its use. This is how the kimono came into being.

These examples are representative of the way in which the sustainable use of raw materials and resources can inspire creativity and lead to iconic products that are now known and loved the world over.

INSPIRATION 2: THINKING AND MANAGING IN CIRCLES

When thinking about the sustainable use of raw materials, you very quickly come to the concept of the circular economy. It’s based on the idea of using materials and products for as long as possible, avoiding waste and minimising the consumption of resources. The underlying concept is an ecological cycle in which there’s no such thing as “waste”, because everything is reused in its entirety (as in the way, for example, that leaves become compost).

Implementing a circular economy means fundamentally reconceiving and changing the “linear” economic system in which people buy products, use them briefly and then throw them away. In a circular economy, both existing business models and consumer behaviour would change. Rethinking doesn’t just begin with the recycling of a product, but early in the development and design phase, when the reusability of the materials used and the reparability of a product are taken into account.

Many of today’s materials, products and services are already based on the principles of the circular economy: more and more products are made from renewable materials, for instance garments made from orange peel, handbags made from cactus leaves or insulating panels made from popcorn, all of which can be composted after use. Another idea is to borrow rather than buy items of clothing or rarely-used appliances such as drills or waffle irons. And there are charging cables and smartphones that you can easily repair at home all by yourself.

In order to motivate even more companies to adapt their business models towards a resource-conserving circular economy, various policies and legislative proposals are being discussed. These include mandatory materials certificates, which provide information on the materials contained in a product and their recyclability, or the right to repair, which the European Parliament already imposed on electrical appliances in April 2024.

INSPIRATION 3: SUSTAINABLE BUILDING

The construction sector is one of the most resource-intensive economic sectors in the world. In Germany, 90 per cent of all mineral resources are used in the manufacture of building materials and products (source). In addition, 40 per cent of global CO₂emissions can be attributed to the construction sector (source). Saving raw materials in the construction sector would therefore have particularly far-reaching consequences.

What might this look like in concrete terms? Problematic building materials such as concrete or bricks, whose production generate particularly high CO₂emissions and/or which are difficult to recycle, can be improved with more sustainable materials or even replaced by them. Here are two examples:

SELF-HEALING CONCRETE

Modern concrete tends to form small cracks, which can increase if water seeps in. As a result, many concrete structures, such as bridges, require extensive repairs or have to be demolished after only a few years. An exciting invention to extend the life of such structures, and save on repairs, is self-healing concrete. One method to produce this type of concrete is to add bacterial spores, which are activated when water penetrates. They then begin to mineralise and expand, thereby repairing the concrete.

INSULATING WITH RENEWABLE RAW MATERIALS

Many insulation materials are made of plastics or mineral wool, which are difficult to recycle. In the future, we could use biodegradable alternatives like insulating panels made from popcorn or insulations made from dead seaweedof the sort you can come across when swimming in the Mediterranean. Both materials have good insulating properties and provide natural fire protection.