Aiding adobe: development of contextually responsive seismic reinforcing for Latin American adobe homes

Abstract

Affordable and accessible adobe construction is used extensively by lower socio-economic people throughout Latin America to construct their homes. Adobe's seismic resistance, however, is extremely poor. This study develops an innovative low-cost used car tyre reinforcing system to increase the seismic safety of adobe construction. Tyre treads are circumferentially cut into strips, connected on-site using simple nailed connections, and placed horizontally and vertically around adobe walls. Seismic reinforcing of adobe is not solely a structural challenge. This system is developed cognisant of the social, cultural and economic context for which it is intended. This has required a wide range of research methodologies to be used: literature reviews, field work, laboratory testing and research-by-design. A literature review of Latin American urban context and lower socio-economic housing provides the theoretical framework for the system's development. Field research documents important socio-economic, constructional, and architectural factors to be considered when implementing the system. Structural test results indicate that horizontal and vertical tyre reinforcing significantly improves the performance of adobe construction. Tyre strips hold the loaded wall fabric together and demonstrate flexible but strong behaviour. Under face-loading, the final developed tyre strip arrangement is over six times stronger than an unreinforced wall specimen. Construction aspects have been refined to make the system simpler, quicker to build and more understandable for informal owner/builders. The study finds that socio-cultural desires for 'modern' construction materials is a key challenge facing the tyre strip implementation. Unfortunately, due to its structural limitations, the proposed system does not increase adobe design opportunities, such as facilitating larger openings or multiple storeys which 'modern' materials allow. The visual implications of tyre strip reinforcing have also been considered given Latin Americans place considerable value on the aesthetics of their homes.