Cross-dating of bricks and mortars from historical building, through thermal (TL) and optically stimulated (OSL) luminescence have achieved good accuracy and precision. However this approach is, in many cases, not exhaustive especially for buildings with different construction phases closely temporally spaced to each other. The uncertainties of experimental data added to the reuse of old bricks and/or the presence of mortars applied on restorations represent the main limits to obtain the complete chronology. In the case of the Convento de S. Francisco (Coimbra, Portugal), the dating results were crossed with the stratigraphic study of the building, mineralogical characterization by XRD and colorimetric data of the mortar samples. Thanks to luminescence ages, mineralogical composition and color specification, two phases of construction were identified: the first from the 17 th century and the first half of the 18 th century and the second from the second half of the 18 th century to the first half of the 19 th century. These results were confirmed by mineralogical characterization and colorimetric measurements of mortars that identify two different types of materials in aggregate/binder ratio terms and superficial optical characteristics.
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.
Financial support for the meeting Mega-Talks 2 has been provided by the project Moving megaliths in the Neolithic (PTDC/EPH-ARQ/3971/2012), funded by FCT (Fundação para a Ciência e a Tecnologia, Portugal) and the Municipality of Redondo (Portugal).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.