Stabilised Earth Block

Compressed earth blocks are made in a press, which allows a large compressive force to be imparted to the brick. This means that a lower water content can be used than for adobe, because a great compactive effort is applied, and thus a brick with a higher dry density brick is obtained. As a press is used, moulds can be inserted to allow the brick to be faceted around the edges, and frogs and raised sections can be added to improve interlocking.

In some cultures, cement or other binders are added to the earth block mixture to improve the mechanical properties, and in these cases it is important to ensure that sufficient water is added to allow the full cementing reaction to take place.

A large amount of research has been undertaken by non-governmental organisations into the improvement of earth brick presses for use in developing countries. The CINVA ram was developed in the 1950s, and many agencies have contributed to the subsequent development of the presses, including the BREPAK machine and the Auram 3000 press developed and manufactured by the Auroville Earth Institute.

Cement-stabilised earth blocks must be allowed to cure before they are used in a structure. A mortar similar to that of the brick is used for their construction. Compressed earth blocks offer a viable alternative to fired brick or cement block construction. Buildings are usually painted or rendered using a cement-based render, and as a result do not appear any different from other construction types.

Cement stabilised earth block press