Building Heritage In The Alto Douro Wine Region, Portugal – Tabique Wall Nails Characterization

Abstract

The Alto Douro Wine Region, a region located in the northeast of Portugal, presents an abundant building heritage which consists of tabique constructions, a vernacular construction technology. This technology uses raw materials such as stone, an earth-based material and wood, besides metal nail sensure the timber connections and the required structural safety. Previous research works have shown that most of the existing tabique buildings, in this region, present signs of marked deterioration and some of them are clearly near collapse. This reality is justified, among others, by the non-engineered character of this construction technology and subsequent loss through time of the associated empirical technical knowledge, consequently, conservation and repairing works are urgently needed. These aspects, added to the dearth of knowledge related to this building heritage have motivated this research work which is focused on studying the nails traditionally applied in those tabique buildings. In this article, and for the first time, a nail geometrical and material characterization is presented and discussed. The results highlight a wide nail dimensional variety, being iron the main chemical element identified. Beyond that, this study demonstrates that those nails should no longer be maintained in service and that new nails should be applied in future conservation and strengthening works. Finally, some guidelines regarding tabique rehabilitation and nail rusting prevention are mentioned.

Earth-based construction material field tests characterization in the Alto Douro Wine Region

“…Studies regarding this technology, although initiated in 2008 [5], have at this stage analysed some aspects of tabique buildings located in the Trás-o-Montes e Alto Douro Region, as materials characterization [1,3,[5][6][7], building state of conservation [1,5], tabique walls typologies [8], numerical modelling [9], thermal insulation [10,11], re resistance and rehabilitation works. The present work follows the study presented in [1,3,5,12] and relative to laboratory tests applied to characterize the earth-based material (EBM) present in tabique walls.…”