http://repositorio.lnec.pt:8080/jspui/handle/123456789/33 Sat, 04 Apr 2026 21:09:14 GMT 2026-04-04T21:09:14Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1018090 Understanding Corrosion in Restored Concrete Zones Through Sensor Data Analysis Pereira, E. V. Editors: José C. Matos, Paulo B. Lourenço, Daniel V. Oliveira, Jorge Branco, Dirk Proske, Rui A. Silva, Hélder S. Sousa Despite reinforced concrete bridges being highly durable, they remain susceptible to natural ageing and disasters, potentially impairing their performance over time. This drives an increase in maintenance, rehabilitation, and repair expenditure, accounting for half of the construction sector spending in developed nations. Structural and durability monitoring becomes crucial to establish long-term maintenance schedules and ensure safety throughout their lifespan. Typically, maintenance schemes rely on sensor systems that periodically or continuously collect information, utilizing various sensors such as electrical, optical, chemical, and sound sensors. Sensor reliability is subject to environmental factors, its own durability and potential power outages, which can temporarily or permanently interrupt data acquisition making difficult or even impossible damage detection. This study focuses on analyzing the evolution of concrete electrical resistivity over time in five repaired concrete zones instrumented with durability sensors to estimating corrosion progression. Based on a compiled and filled database by the authors, this research utilizes degradation models and correlation indices to estimate concrete cover deterioration. Leveraging over fourteen years of sensor data from a reinforced concrete structure, the study focuses on comprehending concrete resistivity evolution in repaired zones to gain insights into the loss of protective concrete cover characteristics to reinforcement corrosion. The study deliberates its findings and extends recommendations for applying this approach to other sensor analysis, enabling a more profound understanding of concrete structure health and longevity. Sat, 01 Jun 2024 00:00:00 GMT http://repositorio.lnec.pt:8080/jspui/handle/123456789/1018090 2024-06-01T00:00:00Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1016971 Fernandina wall of Lisbon: mineralogical and chemical characterization of rammed earth and masonry mortars Infante Gomes, R.; Santos Silva, A.; Gomes, L.; Faria, P. This paper aims to provide information on rammed earth and masonry mortars of the Fernandina defensive Wall of Lisbon, Portugal, which was built in the second half of the 14th century. No previous information exists concerning the materials and construction techniques used in this defensive structure, which is essential to increase knowledge and to define requirements for a reliable conservation. An experimental campaign was carried out on samples extracted in nine different sections of this structure, which were analyzed by X-ray diffraction, thermogravimetry and wet chemical analysis. Calcitic lime was employed as a binder in the stone masonry bedding mortars and was also identified in the rammed earth samples. The results obtained allowed us to verify the use of different binders and aggregates, with heterogeneous binder/aggregate ratios, in different sections of the Wall. To reduce time for lime preparation and to achieve a durable lime matrix, most probably quicklime was used and hydrated together with the moistened earth to produce rammed earth and masonry bedding mortars. Sun, 13 Feb 2022 00:00:00 GMT http://repositorio.lnec.pt:8080/jspui/handle/123456789/1016971 2022-02-13T00:00:00Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1016842 Characterization of mortar from Casa Barbot (Portugal), a case study from the beginning of the 20th century Maljaee, H.; Santos Silva, A.; Velosa, A. The popularity of natural cement (Roman cement) in buildings from the late 19th and the beginning of the 20th century and the high diversity of characteristics of natural cement demand research of mortar and binders used in the buildings of this period in Portugal. Understanding the type of binder used in the historic buildings will help the project/intervention team to make the best decisions in terms of the development of compatible mortars for historical conservation purposes. Casa Barbot is one of the Art Nouveau examples of the beginning of the 20th century in Portugal. The garden of this building is characterized by peculiar elements in terms of materials and architecture. Full characterization of the mortars employed in the construction of this building as well as identification of the used binder is the main objective of this study. The study comprises a wide range of laboratory characterization techniques such as X-ray fluorescence (XRF), X-ray diffraction (XRD), petrography, open porosity, density, water absorption by capillarity, and compressive strength. The results show the diversity of compositional characteristics in the mortars used in the decorative elements in the period garden of Casa Barbot. All mortars are composed of Portland cement with a mix of additives such as blast furnace slag, limestone filler, air lime, and the occasional presence of charcoal. The results raise doubt about the use of natural cement as stated in the historical documents. This study will broaden the scientific knowledge of the materials of that period in Portugal to provide a comprehensive plan for the preservation of historical buildings. Fri, 13 Jan 2023 00:00:00 GMT http://repositorio.lnec.pt:8080/jspui/handle/123456789/1016842 2023-01-13T00:00:00Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1016833 DB-HERITAGE Data on construction materials history Correia, M. J.; Santos Silva, A.; Fontinha, I. R. Paulo B. Lourenço, Carlos Maia, Arnaldo Sousa Melo e Clara Pimenta do Vale Recommendations on the intervention plans, materials, and techniques for the conservation and restoration of built heritage should be based on sound knowledge of both heritage and its constituent materials conservation condition. Accordingly, data on built heritage and building materials and their history is essential for improving knowledge on ancient materials and techniques, for materials performance modelling benchmarking and related development, and for further supporting the decision-making process for the conservation/restoration works. Nevertheless, of the latest developments and increased awareness, basic information on physical, chemical, and mechanical characterisation of construction materials is not always accessible or findable. To prevent these shortcomings, DB-HERITAGE system (http://dbheritage.lnec.pt/) provides physical and digital repositories for archiving data on the history, properties and performance of architectural and archeologic heritage and related building materials. This paper displays examples of samples and the related data from historic building materials, including wrought iron, protection coating and mortars, archived at DBHERITAGE, highlighting their scientific, educational, and historical values. Fri, 01 Sep 2023 00:00:00 GMT http://repositorio.lnec.pt:8080/jspui/handle/123456789/1016833 2023-09-01T00:00:00Z