Is rammed earth suitable for high-altitude desert climates?

Design Considerations for High-Altitude Desert Climates

When building rammed earth structures in high-altitude desert climates, designers must consider the effects of extreme temperature fluctuations, low humidity, and strong solar radiation. One key strategy is to increase the thermal mass of the walls by using a higher proportion of sand or aggregate in the soil mix. This helps to absorb and release heat more slowly, reducing temperature extremes within the structure.

Formwork and Compaction Techniques

To achieve a high-quality rammed earth finish in high-altitude desert climates, it is essential to use a robust and well-designed formwork system. Wooden or metal forms should be anchored securely to the foundation and supported with bracing to prevent collapse under the weight of the compacted soil. Compaction is critical to ensure the structure’s stability and integrity; a minimum of 3-4 passes with a 6-ton hand tamper or equivalent machinery should be applied to achieve the desired density.

Soil Mix and Moisture Management

The desert climate’s low humidity requires careful management of the soil mix’s moisture content to prevent cracking and damage. A mix of 20-30% clay, 40-50% sand, and 30-40% aggregate is a good starting point, with a moisture content of around 10-12%. To maintain this moisture level, builders should ensure the soil mix is kept covered and protected from direct sunlight and wind. Regular monitoring of the mix’s moisture content and adjusting the proportions as needed will help to minimize the risk of defects and ensure a durable rammed earth structure.