http://repositorio.lnec.pt:8080/jspui/handle/123456789/32 Sat, 04 Apr 2026 21:09:15 GMT 2026-04-04T21:09:15Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1018088 Fire-retardant and fire-resistant coatings: From industry to the potential use on cultural heritage Soares, I.; Ferreira, J.; Silva, H. M.; Rodrigues, M. P. Fire is one of the most damaging deterioration agents in a short time of action. It can cause considerable damage, leading to the loss of lives and possessions. Concerning fire safety recommendations, buildings must be protected by an integrated system of passive and active measures. Two passive measures widely used in many industries are fire-retardant and fire-resistant coatings. These systems provide a fire-protective layer to the surfaces of flammable and non-flammable materials, delaying or preventing their ignition, reducing the heat transfer from the source to the substrate and decreasing the flame spread and the release of smoke and toxic gases. When exposed to fire, according to the different mechanisms of action, fire-protective coatings (FPC) can be classified as non-intumescent and intumescent. Despite being widely mentioned in heritage fire safety guidelines, studies on their application in the field are still scarce. Namely, research on the safety and efficacy of their application near collections (in support materials) and systematic studies comparing different formulations. Therefore, this research assembles interdisciplinary studies on the use of FPC to deepen knowledge and theoretically identify the feasibility of their application in collection support/storage materials or exhibition furniture (bookshelves, cabinets, plinths) in heritage environments. Mon, 01 Jul 2024 00:00:00 GMT http://repositorio.lnec.pt:8080/jspui/handle/123456789/1018088 2024-07-01T00:00:00Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1018063 Freeze-thaw durability of vacuum infused glass fibre composites with unsaturated polyester and vinyl ester matrices Hasan, T.; Correia, J. R.; Garrido, M.; Soares, F.; Cabral-Fonseca, S.; Jorge, M.; J. SENA-CRUZ This paper presents an experimental study about the effects of freeze-thaw cycles (FTC) on the mechanical and thermomechanical properties of glass-fibre reinforced polymer composite laminates produced by vacuum infusion using two different polymer resins: unsaturated polyester (UP) and vinyl ester (VE). Following preconditioning in distilled water for 30 days at 20 ◦C, the composites were subjected to 100, 200 and 300 FTC, with temperature ranging from - 20 ◦C to 23 ◦C. After the preconditioning and each ageing period, the mechanical properties of the composites were assessed through tension, compression, flexure, in-plane shear and interlaminar shear tests, as well as DMA, which were complemented by FTIR analysis and SEM observations. The results obtained indicate a slight-to-moderate reduction of glass transition temperature and mechanical properties, especially of flexural strength (up to 29 %) and compressive strength (up to 16 %). These reductions were partially reversible upon drying, highlighting relevant moisture-induced plasticization effects. On the other hand, no clear evidence of significant hydrolysis or fibre-matrix debonding was identified from respectively FTIR and SEM. Overall, the VE composite exhibited better overall performance than the UP composite. It was not possible to identify clear differences in the freeze-thaw durability performance of the vacuum infused composites tested in this study compared to pultruded composites reported in the literature. Fri, 01 Nov 2024 00:00:00 GMT http://repositorio.lnec.pt:8080/jspui/handle/123456789/1018063 2024-11-01T00:00:00Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1017009 Durabilidade da ligação betão-CFRP em sistemas de reforço com as técnicas EBR e NSM sob efeito de envelhecimento natural R. CRUZ; L. CORREIA; Cabral-Fonseca, S.; J. SENA-CRUZ A durabilidade das estruturas de betão armado reforçadas com polímeros reforçados com fibras de carbono (CFRP) tem vindo a ser estudada essencialmente através de protocolos de envelhecimento acelerado em laboratório, existindo poucos estudos de envelhecimento natural (real). Este trabalho pretende contribuir para o conhecimento da durabilidade da ligação entre betão e laminados de CFRP, aplicados segundo as técnicas EBR e NSM, utilizando um adesivo epoxídico. Foi implementado um programa experimental, que incluía um ambiente de referência (20 °C / 55% HR) e quatro condições de exposição natural, induzindo principalmente (i) carbonatação, (ii) ciclos gelo-degelo, (iii) temperaturas extremas, e (iv) ação de cloretos. Foi ainda estudado o efeito da imersão contínua em água a 20 °C. A durabilidade da ligação foi avaliada até 2 anos de exposição, através de ensaios de arranque direto. Constatou-se que o desempenho da ligação nos envelhecimentos naturais apresentou níveis relativamente reduzidos de degradação para ambas as técnicas de reforço. Tue, 01 Mar 2022 00:00:00 GMT http://repositorio.lnec.pt:8080/jspui/handle/123456789/1017009 2022-03-01T00:00:00Z http://repositorio.lnec.pt:8080/jspui/handle/123456789/1017008 Durability of bond of EBR CFRP laminates to concrete under real-time field exposure and laboratory accelerated ageing R. CRUZ; L. CORREIA; Cabral-Fonseca, S.; J. SENA-CRUZ The durability of bond between carbon fibre-reinforced polymer (CFRP) laminates and concrete with the externally bonded reinforcement (EBR) technique was investigated under real-time field exposure (RTFE) and accelerated ageing. The experimental program, over two years, includes four outdoor environments inducing carbonation, freeze–thaw attack, extreme temperatures, and airborne chlorides from the ocean. A laboratory environment (20 ◦C/55% RH) was used as reference environment. Additionally, a water-immersion environment (20 ◦C) was also considered. Relatively low values of bond degradation were observed, where the maximum pullout force varied between 􀀀 4 % and +16 % under RTFE, while on water–immersed specimens, the maximum pullout force decreased by ~8 %. Mon, 27 Mar 2023 00:00:00 GMT http://repositorio.lnec.pt:8080/jspui/handle/123456789/1017008 2023-03-27T00:00:00Z