In recent decades, mainly conventional "industrial" building materi- als like concrete have been increasingly used. However, these materi- als bring significant ecological problems. The production of concrete requires cement, which releases large amounts of CO2. Cement production is responsible for about eight percent of global carbon dioxide emissions. Additionally, materi- als like bricks and tiles, once fired, cannot be returned to their original state. In 2021, 59,848,000 tons of waste from concrete, bricks, tiles, and ceramics were generated. Despite a high recycling rate of 94%, about 3,590,880 tons of waste remain unprocessed.4 Often, burning for energy or use in landfill construction counts as recycling, which does not represent a sustainable solution.

1. Global Availability 2. Recyclability: Earth is 100% recyclable and can be returned to its original state. At the end of their lifespan, earth structures can be easily dismantled and returned to nature. 3. Durability: Earth houses can last for hundreds of years with proper maintenance. THE WEAKNESS OF THE MATERIAL AND HOW ARCHITECTURE DEALS WITH IT But of course there are also downsides working with earth. One of the main challenges in rammed earth architecture and earth construction in general is the erosion of the material due to rain and flowing water. Addressing this problem requires careful planning and the implementation of protective measures. In current architectural practice, various strategies are employed to minimize the effects of water on earth buildings. By addressing these challenges, earth construction can become more resilient and viable, further promoting its use as a sustainable and eco-friendly building material.

Inspired by our research, we ask ourselves: How can we turn material weakness into strength and expand the possibilities of designing with rammed earth? Our project creates recyclable, unfired rammed earth tiles that embrace natural erosion from rainwater as a design feature. The tiles are intended as an additional layer for clay walls, which protect the underlying wall but themselves erode over time. By turning material weakness into strength, we explore sustainable, dynamic aesthetics in architecture.

What material can we find in our immediate surroundings? can we find local material, we can work with to produce rammed-earth tiles? We visited construction sites close to university and collected earth near Golm (Potsdam) to compare its qualities. At a site near the university, the soil was very sandy with small brick fragments. We had to add a lot of clay and larger stones to achieve the right mix. We also collected old bricks, which we crushed to the right size. Their sharp edges provide more stability for rammed-earth tiles.

The graph shows how often the ball was dropped from a height of 1.5 m.

While erosion is part of our concept, durability remains an important value in our design approach. because only durability can prevail as a sustainable solution for a design approach. With the aim of slowing down erosion, we therefore experimented with clay and tested various additives in an attempt to make it less susceptible to erosion from water. We experimented with small clay tiles to which we added various additives and observed their reaction to water. We also treated the surfaces to make them more water-repellent. Our intention was to coat the surface of the final tiles in places and thereby control erosion in some areas.

To see how the water resistance changes, we added different ingredients to small clay-bodies, put them into water and observed how they erode during time. The result was quite impressive.

After adding tadelakt, wax, casein, konjak and oil to the surface we put the test-tiles into water and compared the erosion of the material with untreated parts.

By testing the waterflow on different shapes, we tried to calculate the erosion and the change of the shape.

Our design, "mäander," is deeply inspired by the natural processes of erosion, where wind and weather gradually shape the landscape into intricate and organic forms. The journey began with an observation of topographical features and gully erosion. To refine our concept, we created small prototype tiles, experimenting with various shapes.

In our production process, we produced the molds using CNC technology and enclosed them with plates to ensure precision. We then used a manual pressing tool to press earth into the molds to form the tiles.