Vernacular Caramel´s Adobe Masonry Dwellings – Material Characterization

Abstract

In Pinhal Novo, Palmela, and neighboring municipalities, southern Lisbon region, there are a great number of small adobe masonry dwellings, made in the first half of the 20 th century. The vernacular dwellings were constructed by families that came from the north/center region of Portugal to work at the local manors, and were called Caramel´s. Adobe samples from three of these dwellings were collected in Pinhal Novo and Moita, and tested for particle size distribution, X-ray diffraction, color, bulk density, ultrasonic pulse velocity, thermal conductivity, dry abrasion, flexural and compressive strength, capillary absorption and drying. It was possible to conclude that the adobe was not chemically stabilized and had no vegetable fibers. Average values for the adobe properties were defined and results were analyzed, revealing comparable to unstabilised adobe and even to lime stabilized adobe from other regions. The data on Caramel´s adobe can support the design of interventions to preserve at least some of these Caramel´s vernacular dwellings.

Research on the building materials of adobe house in the Neolithic period at the Qingtai site, China

“…Because high content of fine granular argillaceous cement would make the adobe unstable in the presence of water, resulting in the cracking of the adobe masonry, weakening or even destroying the stability of the building structure, it was necessary to add a certain amount of fiber or coarse sand to improve the properties of adobe (Dormohamadi & Rahimnia, 2020; Mellaikhafi et al, 2021; Quagliarini & Lenci, 2010). Interestingly, the adobe remains found in different civilizations around the world displayed that the ancient humans often used soil containing a large amount of argillaceous cement to make adobe (Costi de Castrillo et al, 2017; Mauricio et al, 2021; Silva et al, 2020). They would like select fibers to improve the performance of adobe but rarely added coarse aggregate to it (Houben et al, 2004; Li, 2016; Mortada, 2016).…”

Vernacular earthen buildings from Leiria, Portugal – Architectural survey towards their conservation and retrofitting

“…Regarding another regions in Portugal, Fonseca (2007) identified adobe with 0.40 m × 0.20 m × 0.12 m (length × width × thickness) in Avis, Alentejo, (Figure 1A), identified adobe with 0.51-0.50 m x 0.38-0.30 m x 0.10 m in Setúbal region, (Figure 1A), and Varum et al (2008) and several other researchers identified adobe with 0.45 m × 0.30 m × 0.15 m in the district of Aveiro (Figure 1A). Contrary to what happens in other regions, such as Pinhal Novo, Setúbal district (Sampaio et al, 2017;Silva et al, 2020) where the adobe width defined the walls thickness, in Leiria that was defined by the adobe length in the structural exterior walls. However, the wall thicknesses were not so different between both regions as Leiria's adobe length (Table 1) seems to be close to Setúbal's adobe width .…”

“…However, the characterization of materials is still scarce. Some studies have already been performed on vernacular dwellings, namely lime-stabilized adobe masonry from Aveiro region (Coroado et al, 2010;Silveira et al, 2012;Costa et al, 2019), unstabilized adobe masonry from Setúbal region (Silva et al, 2020) and rammed earth from Alentejo (Gomes et al, 2014;Gomes et al, 2019) or from Western Algarve (Mateus et al, 2015;Mateus et al, 2019).…”

“…In Aveiro region (Figure 1), about 40% of all buildings have adobe masonry (Silveira et al, 2007). Between Sado and Tagus rivers (Setúbal region -Figure 1), almost all the rural old buildings have adobe masonry (Sampaio et al, 2017;Silva et al, 2020). In Alentejo (Figure 1), there is a high number of rammed earth rural dwellings and farm buildings (Gomes et al, 2014;Correia, 2007).…”

“…Nonetheless, an increasing interest on using this material has been observed in the last decades, both for modern constructions and retrofitting of old buildings, largely due to ecological concerns. That is the case of the use of eco-efficient earthen plasters (Santos et al 2017;Parracha et al, 2019a;Santos et al, 2021), adobe (Costa et al 2018;Silva et al 2020) or rammed earth (Fernandes et al, 2019).…”