http://repositorio.lnec.pt:8080/jspui/handle/123456789/1010710 Mon, 26 Oct 2026 10:13:30 GMT 2026-10-26T10:13:30Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1019869 Tropical earthen plastering mortars: Effects of earth mineralogy, earth-to-sand proportion, and moisture conditioning Luiz, A.; Rezende, M.; Santos Silva, A.; Faria, P. This study investigates the physical and mechanical behaviour of tropical earthen mortars, focusing on the influence of clay content, mineralogy and moisture condition. To address the limited documentation on tropical earthen mortars, eleven mortars were produced using three tropical earth and three proportions of added sand. Two of the earth were of pedogenetic origin, whereas the third was derived from gneiss aggregate washing residue. The added sand consisted of crushed basalt fines generated during gravel production. Materials were characterised by particle-size distribution and mineralogical composition, and the mortars were evaluated for porosity, bulk density, shrinkage, flexural (FStr) and compressive (CStr) strengths. Moisture sensitivity was assessed under high-humidity conditioning through the degree of saturation at mechanical failure. The results show that clay content and mineralogical characteristics strongly influenced water demand, shrinkage, porosity and density. Porosity ranged from 30% to 48%, with higher values in clay-richer mortars. Sand addition substantially reduced shrinkage, reaching up to 79% in the most clay-rich mixtures. FStr ranged from 0.6 to 1.0 MPa, while CStr ranged from 0.5 to 1.0 MPa, with several formulations exceeding the minimum requirement of EN 998-1. Moisture had a marked effect on performance, with CStr generally decreasing more sharply than FStr as saturation increased. Overall, the results demonstrate that clay content, mineralogy and moisture state play a decisive role in the behaviour of low-embodied-energy tropical earthen mortars, supporting their wider application as building plasters. Fri, 01 May 2026 00:00:00 GMT http://repositorio.lnec.pt:8080/jspui/handle/123456789/1019869 2026-05-01T00:00:00Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1019523 IPaintS - Intelligent Coatings for Concrete Structures: immobilization of pH indicators on coating membranes Cristino, A.; Lopreto, J.; Silva, H. M.; Santos Silva, A.; Rodrigues, M. P.; Cabral-Fonseca, S.; Ferreira, O.; Nunes, J.; Soeira, B.; Galhano, R. Grantham, M.; Custódio, J.; Real, S. In Portugal and over the world, a significant number of concrete structures face challenges due to expansive chemical reactions, such as the alkali-silica reaction (ASR). These reactions have been shown to cause various types of damage, with microcracking being the most common, resulting from internal stresses created by the expansion of reaction products. It is well-documented that, over time, these microcracks can develop into significant fissures due to the hygroscopic nature of these products, which accelerates concrete degradation and potentially compromises structural integrity. One key aspect of ASR products is the presence of alkaline hydroxides in the gel formation process, resulting in elevated pH levels. When this gel reaches the concrete carbonated surface, a change in pH occurs. Based on this premises, the project IPaintS was undertaken to develop a coating that could detect the formation of ASR products on concrete surfaces by identifying variations in pH. This paper presents the results of the preliminary tests conducted, specifically the tests performed to confirm the possibility of immobilising pH indicators in a coating membrane and assess performance characteristics of the functionalised coating. Results show the effective immobilization of a pH indicator on a coating membrane without the loss of some fundamental properties of both the indicator and the coating membrane. Fri, 13 Jun 2025 00:00:00 GMT http://repositorio.lnec.pt:8080/jspui/handle/123456789/1019523 2025-06-13T00:00:00Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1019340 Materiais de construção produzidos e usados em Portugal que podem suscitar preocupação do ponto de vista da proteção radiológica Trindade, M.; Malta, M.; Fonseca, H.; Santos Silva, A.; Costa, D.; Batista, F.; Pereira, A.; Dinis, M. Na construção civil, é comum a utilização de materiais geológicos, seja diretamente ou incorporados nos materiais de construção. A presença de radionuclídeos naturais nesses materiais pode resultar em exposição à radiação ionizante, seja por meio da exposição externa à radiação gama ou pela inalação do gás radão. A Agência Portuguesa do Ambiente estabelece medidas adequadas para controlar os materiais de construção, visando proteger a população contra radiações ionizantes no interior dos edifícios. Um estudo foi conduzido com o objetivo de identificar os materiais de construção produzidos e utilizados em Portugal que possam gerar preocupações radiológicas, com especial ênfase na radiação gama. Neste trabalho, apresentam-se os resultados relativos ao índice de concentração de atividade (I), relacionado com a dose de radiação gama proveniente dos materiais de construção, permitindo rastrear os materiais que podem fazer com que o nível de referência de dose seja excedido. O estudo destaca maior preocupação radiológica em relação aos granitos e pozolana natural, bem como alguns subprodutos e produtos industriais, como cinzas volantes, argila expandida, betão com agregado granítico e determinados pavimentos e revestimentos cerâmicos. Tue, 01 Apr 2025 00:00:00 GMT http://repositorio.lnec.pt:8080/jspui/handle/123456789/1019340 2025-04-01T00:00:00Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1018727 Monitoring the state of conservation of Paimogo Fort - digital survey Santos Silva, A.; Henriques, M. J.; Roque, D.; Veiga, M. R.; Lopes dos Santos, A. R.; Correia, M. J. M. Grantham, J. Custodio and S. Real This article discusses and presents the methods and results of the digital survey carried out, in 2025, of Paimogo Fort, a military structure built in 1674 in the municipality of Lourinhã. The digital survey aims to safeguard and monitor the conservation state of this classified coastal heritage site. Paimogo Fort underwent a conservation intervention in 2024 to preserve and strengthen the values of its individual and collective memory, transforming it into a meeting point for the memories of local communities and as a source for recovering and bringing awareness of traditional knowledge within the region. Sun, 01 Jun 2025 00:00:00 GMT http://repositorio.lnec.pt:8080/jspui/handle/123456789/1018727 2025-06-01T00:00:00Z