Traditional technology repeatedly rammed the end of a wooden pole into the earth mixture to compress it. In modern rammed earth buildings, the walls are constructed on top of conventional footings or a reinforced concrete slab base. Higher compressive strength might require more cement. The main difference is that instead of the sand/gravel used as an aggregate in concrete, poured earth uses ordinary soil (although this soil needs to meet certain specifications) and generally uses less Portland cement. Earth building, including rammed earth building, produces very low carbon emissions.
Rammed earth can represent a much lower carbon footprint than concrete. This paper covers a detailed research carried out on CSRE to establish strength and durability properties together with applications in the form of pilot projects. Stabilizing earth with cement and ramming at optimum moisture content forms cement stabilized rammed earth (CSRE), a building material with sufficient strength and durability but low in embodied energy. Similar to the shutter for concrete, CSRE formwork should have sufficient strength, stiffness and stability to resist stresses exerted during erection, placing the soil, and dismantling. So when cement is added to rammed earth, Krahn notes that “detractors may argue that this means we are effectively creating nothing more than damp-pack concrete.” Indeed, some have argued that adding cement is essentially greenwashing. We discovered through sample testing that the soil from our site was uniquely suited for rammed earth, one of the oldest methods of construction. If the soil for the walls is close to the project, then transportation fuel consumption will be low. If careful formulation allows design strengths to be met with 7% or less cement, then a big savings in CO2 will accrue. The reason rammed earth stays together is a combination of the materials used, their particle size, their moisture content and the pressure applied.
Cement stabilised rammed earth is cured for a minimum period of 28 days. "We see this project as a … Quite rightly, but still a bit in the wrong, because, although rammed concrete has many disadvantages compared to its well-proven reinforced successor, it also has certain properties that make it stand out and make it interesting for certain projects. Construction of cement stabilized rammed earth walls with slip form mould. Well produced cement stabilised Rammed Earth walls can be anywhere between 5 to 20 MPa. Poured earth is similar to ordinary concrete, in that it is mixed and formed like concrete and uses Portland cement as a binder. Contemporary slip formwork in use. However, there is a confusion between rammed earth - a mix of clay, sand and stones - and dry-pack concrete, too often called ‘stabilised rammed earth’. Stabilizing earth with cement and ramming at optimum moisture content forms cement stabilized rammed earth (CSRE), a building material with sufficient strength and durability but low in … Stabilised rammed earth is a variant of traditional rammed earth that adds a small amount of cement (typically 5–10%) to increase strength and durability. Poured Earth. Using rammed earth was a way of making the rural hospital complex, which is designed to treat 100,000 patients a year, both low cost and more sustainable. Called cement-stabilised rammed earth (CSRE), it consists of a mix of low-clay soil, water and cement. The compressive strength of rammed earth is dictated by factors like, soil type, particle size distribution, amount of compaction, moisture content of the mix and type/amount of stabiliser used. Modern technology replaces the pole with a mechanical ram.