Earth-brick arch vaults, hospital in Zambia

Cement stabilised earth-bricks ‘CSEB’ were manufactured on site using a ‘Hydraform’ machine, and used to create new arch vaults for roofs and supporting walls of a new hospital in Sachibondu, Zambia.

The ‘hydraform’ machine makes consistent and regular bricks with interlocking features to allow mortarless construction. A small amount of cement is mixed with earth from the ground (and local sand if clay content in the soil is too high).

The made catenary arch vaulted roofs using 80mm thick earth bricks for arched roofs up to 8.0m clear span. The vaults work in pure compression only.

We developed a design tool using Python script to analyse the arches, using the elastic centre method, to cross check our finite element analysis models. Finite element analysis does not always accurately model compression only structures, so this checking process gave us confidence in our design.

This hospital was completed in September 2017 by a dedicated team of local people, local craftsmen and women, and volunteers from the UK, all organised monitored and coordinated by Orkidstudio.

  • Architect: Orkistudio
  • Photography: Chevy Thom