Rammed earth school in a Gambian context A study of how rammed earth can be used as load-bearing material when constructing a school in The Gambia

Abstract

The aid organisation Eivor Björkman Gambia Aid are planning to build a school called Eivor Björkman Elementary in the neighborhood Brufut in The Gambia. The school is decided to be built with rammed earth as the load-bearing structure. In collaboration with Eivor Björkman Gambia Aid, Detail Group and Earth Lab Studio, this thesis is investigating how a rammed earth school can be built in The Gambia and what adaptations might be needed to the local context. Through a pre-study about rammed earth and eight weeks of field studies in The Gambia, challenges regarding earth building in the Gambian context as well as a school context are identified and evaluated. The building process for rammed earth is evaluated through workshops in Sweden and The Gambia along with a test method developed and evaluated for achieving the compressive strength of rammed earth on site. Specimens made with earth from both Sweden and The Gambia are rammed and compression tested. A prototype of a shallow vaulted slab is constructed in collaboration with a compressed earth block entrepreneur. The prototype is built to assess if the design can be a possible slab option and how the building process would have to be adjusted to be used in a rammed earth building. Simplified calculations are performed for verification of suitability. Several uncertainties connected to construction in The Gambia are realized and discussed. Common solutions to challenges are presented and possible adaptations to the Gambian context and the school context are presented before a final choice of solution is selected and motivated. It is concluded that one of the main challenges is protecting the rammed earth structure from water, especially during the rainy season. This is done by using a "boot" and a sufficient roof overhang. Another important aspect to consider is the erosion of the walls, which in the school context must be considered thoroughly to withstand children using the school.