Steep Catenary Earth-Brick Shells as a Low-Cost Housing Solution

Abstract

The structural advantages associated with the catenary shape strongly endorse its use for small to medium-sized unreinforced masonry shell structures. Furthermore, the adoption of low-cost materials, such as earth bricks, enables relatively cheaper construction than that associated with standard construction materials. However, earth masonry is weak in tension and flexure; hence, there is a need to eliminate tension forces when designing and building with these materials. In this paper, the implementation of steep catenary vaults for application in low-cost housing is examined. Design considerations are presented based on case-study investigations, experiences gained through shells designed by the authors, and through the assessment of related loading stipulations presented in the literature. An important finding is that wind loading may govern the design of masonry catenary shells—particularly those with steep profiles. It is also presented that certain elements, such as gable walls and window frames, which are often attached to these shells, have a tendency to cause cracking if they restrain thermal movement. Furthermore, shrinkage of mortar may also lead to cracking if restraint is generated during construction.