João Carlos Lanzinha

An analytical approach to assess the influence of the massive wall material, thickness and ventilation system on the Trombe wall thermal performance

The influence of the massive wall material, thickness and ventilation system on the Trombe wall thermal performance was analysed based on an analytical methodology. Results obtained from experimental work will also be added to this study. During the heating season, for the non-ventilated Trombe wall, the global heat gains decrease is not proportional to the thickness increase, and this ratio depends on the massive wall material heat storage capacity. A ventilation system in the massive wall leads to higher heat gains due to the air convection, but this growth is not in the same proportion for the different materials. If solid brick or earth is used, heat gain values are much higher than those obtained if there is no ventilation system, increasing to the double in the case of earth and 2.5 times more in the case of solid brick. When the massive wall is ventilated and made of granite, an increase in the gains of 44.06% is obtained when compared with the non-ventilated. During the cooling season, closing the ventilation system and the external shutter leads to heat gains considerably lower than those obtained during the heating season. In this case, earth can be a suitable material.

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

Abstract The Alto Douro Wine Region, located in the northeast of Portugal, a UNESCO World Heritage Site, presents an abundant vernacular building heritage. This building technology is based on a timber framed structure filled with a composite earth-based material. A lack of scientific studies related to this technology is evident, furthermore, principally in rural areas, this traditional building stock is highly deteriorated and damaged because of the rareness of conservation and strengthening works, which is partly related to the non-engineered character of this technology and to the knowledge loosed on that technique. Those aspects motivated the writing of this paper, whose main purpose is the physical and chemical characterization of the earth-based material applied in the tabique buildings of that region through field tests. Consequently, experimental work was conducted and the results obtained allowed, among others, the proposal of a series of adequate field tests. At our knowledge, this is the first time field tests are undertaken for tabique technology. This information will provide the means to assess the suitability of a given earth-based material with regards to this technology. The knowledge from this study could also be very useful for the development of future normative documents and as a reference for architects and engineers that work with this technology to guide and regulate future conservation, rehabilitation or construction processes helping to preserve this important legacy.

Characterization of tabique walls nails of the Alto Douro Wine Region

Abstract Tabique is one of the main Portuguese traditional building techniques which use raw materials as stone, earth andwood. In general, a tabique building component as a wall consist of a wooden structure made up of vertical boards connected to laths by metal nails and covered on both sides by an earth based material. This traditional building technology as an expressive incidence in the Alto Douro Wine Region located in the interior of Northern Portugal, added to the UNESCO’s Word Heritage Sites List in December 2001 as an ‘evolved continuing cultural landscape’. Furthermore, previous research works have shown that the existing tabique construction, in this region, reveals a certain lack of maintenance partially justified by the knowledge loosed on that technique, consequently this construction technique present an advanced stage of deterioration. This aspect associated to the fact that there is still a lack of scientific studies in this field motivated the writing of this paper, the main objectives are to identify and characterize the nails used in the timber connections. The nails samples were collected from tabique walls included in tabique buildings located in LamegoMunicipality, near Douro River, in the Alto Douro Wine Region. This work also intends to give guidelines to the rehabilitation and preservation of this important legacy.