20th-Century Award-Winning Buildings in Lisbon (Portugal). Study of Plasters, Rendering, and Concrete Materials Aiming Their Sustainable Preservation

Abstract

Conservation, increasing the useful life period of existing significant buildings with minimum consumption of new materials, as much as possible of low-embodied energy, is an important step towards sustainable rehabilitation, while also contributing to the preservation of the cultural heritage. In the context of 20th-century buildings’ conservation, the knowledge of construction techniques and applied materials is essential to pursue sustainable preservation and rehabilitation actions. This paper presents the main construction types and characteristics of a set of architecture award-winning buildings in Lisbon (Portugal) between 1903 and 2002 along with an inspection of the main anomalies detected in renders, plasters, and concrete surfaces. The applied methodology made it possible to classify plasters, renders, and concrete materials according to their state of conservation. The study of 20th-century buildings is justified by the intense renovation activity in the city centres, which leads to the loss of their outer layers and their historical and original values. This study aims to contribute to future conservation actions that will guarantee better preservation concerning sustainable materials, i.e., compatible materials to the existing ones that enhance the durability of the old buildings and minimize the use of new materials.

Physical and Mechanical Properties of Reinforced Concrete from 20th-Century Architecture Award-Winning Buildings in Lisbon (Portugal): A Contribution to the Knowledge of Their Evolution and Durability

“…The first award-winning building was prized in 1938, and the last one was prized in 2002. These buildings' main architectural and constructive characteristics can be found elsewhere [33][34][35][36][37][38][39][40][41][42][43][44][45][46]. The studied buildings do not present degradation signs that may affect their structural integrity, nor are they continuously monitored.…”

“…After sampling, the cores were photographed and macroscopically observed to register some characteristics, such as the type of coarse aggregates, presence of cracks, gels, and deposits. The size of the largest coarse aggregates was measured with a digital caliper, and the concrete carbonation depth was measured by applying a phenolphthalein alcoholic solution directly to the core samples [49], whose results have already been published elsewhere [46].…”

“…The standard CEN EN 1992: Eurocode 2 [48] was applied to calculate the compressive strength that concrete would have at 28 days of age, considering the concrete class prescribed in the construction design project for each case study [46] and thus evaluating the quality of construction at the time of concrete application.…”

Sustaining modern heritage buildings: visual defect categorisation guides for the general condition survey of rendered-painted facades

“…The Modern Movement period is also associated with technological innovation. Already known materials were used with new details (Stazi et al, 2012), new or innovative materials and non-traditional techniques were introduced (Forster et al, 2015;Almeida et al, 2021), new architectural facade elements/styles were implemented (e.g. platbands, exposed concrete with wood grain texture), while some others were abandoned (e.g.…”

“…, 2012), new or innovative materials and non-traditional techniques were introduced (Forster et al. , 2015; Almeida et al. , 2021), new architectural facade elements/styles were implemented (e.g.…”