The tabique is one of the main Portuguese traditional building techniques, which is based on raw materials as earth and wood. In general, a tabique wall is formed by a simple timber structure covered by an earth-based material. Earth has an important role in this system because it protects the internal timber structure along with its finishing function. The Trás-os-Montes e Alto Douro is the northeast region of Portugal and it is very rich in terms of tabique construction heritage. Nowadays, the existing tabique constructions show a generalized and advanced stage of deterioration [1, 2, 3]. This aspect, associated to the fact that there is still a lack of scientific studies in this field, motivated this research work which main goals are to study, both experimental and numerical, the behaviour of this solution in terms of fire reaction using different earth-based material thicknesses. Also, it is intended to motivate and to give guidance for future rehabilitation works in this field. In relation to the earth-based mortar, and based on previous studies, it was shown that it is a material with adequate fire resistance. When exposed to fire action the wood material shows a decomposition process (pyrolysis) and produces a surrounding charring depth layer. On the fire exposure side a charcoal layer, without effective resistance, causes the reduction of the element cross-section. However, this charring depth layer can delay the heating process, from the exposed side, to the wood core section and act as an excellent insulating material. When compared to steel or concrete structures, wooden structures have therefore an improved structural behaviour [4].
This paper present a study on the behaviour of tabique walls, concerning its fire resistance. This
work is based on the experimental analysis of real scale tabique panels. Such walls were made
in pine wood with an earth-based mortar finishing. In order to assess the earth-based mortar
thickness effect on the fire resistance of the wall, three specimens were tested with three
different mortar thicknesses of 15 mm, 10 mm and 5 mm. The earth-based mortar was
previously analysed in the laboratory. The wooden structures were constructed based on
traditional tabique technique. The experimental models were tested in a fire-resistance furnace,
according to the ISO 834 standard fire. Temperatures were recorded using two data acquisition
systems (spot measuring and field measuring). Fire resistance of test elements is expressed as
the time during which the appropriate criteria have been satisfied so that one can predict the
time before collapse, increasing both people and property safety. The obtained results are of
great importance as they allow to improve the knowledge on tabique walls behaviour subjected
to fire conditions. Two performance criteria were verified: the integrity criteria and the insulation
criteria.
