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Advisor(s)
Abstract(s)
Com o aumento da utilização dos materiais compósitos (FRP) são inevitavelmente
encontrados novos problemas. De entre esses problemas, existem preocupações em
relação ao seu comportamento quando expostos ao fogo. No caso de exposição direta ao
fogo, é recomendável que os FRP sejam aplicados com medidas adicionais de prevenção.
É objetivo deste trabalho estudar o comportamento dos materiais compósitos à base de
fibras de carbono (CFRP) ao fogo. Os materiais utilizados são a manta e o laminado de
fibra de carbono. Para tal é apresentada uma campanha de ensaios (10 ensaios com manta
e 10 ensaios com laminado) com amostras de provetes de betão de dimensão 100×100×40
[mm]. O CFRP é colado na superfície dos provetes com resina epoxídica exposta à ação
térmica.
As medidas passivas estudadas neste trabalho são destinadas a impedir a ignição e a
diminuir o impacto dos incêndios através de mecanismos que não necessitam de
intervenção humana. Os materiais de proteção ao fogo utilizados para se atingir o tempo
de resistência ao fogo pretendido são a placa de gesso e as tintas intumescentes.
A superfície reforçada é exposta à ação de dois fluxos de calor por radiação, 35 [kW/m2]
e 75 [kW/m2], provenientes de um calorímetro de perda de massa. A evolução da
temperatura é avaliada através de termopares colocados entre as superfícies de ambos os
materiais permitindo uma análise da influência destes materiais de proteção na
capacidade de reforço estrutural dos CFRP quando submetidos a temperaturas elevadas.
Os resultados apresentados mostram que, nos ensaios realizados, a placa de gesso tem um
melhor desempenho do que a tinta intumescente.
With the increase of composite materials (FRP) applications new safety problems arise. Among these issues, there are concerns regarding their behaviour when exposed to fire. In case of direct exposure to fire, it is recommended that the FRP be applied using additional fire protection measures. An experimental programme was performed in order to evaluate the behaviour of composite materials when exposed to fire, in particular composite materials based on carbon fibres (CFRP). The materials used were the sheet and the carbon laminate fibre Therefore a campaign of tests (10 tests with sheet and 10 tests with laminate) on concrete specimens with 100×100×40 mm was developed. The CFRP sheet is glued on the surface of the specimens using epoxy resin and exposed to a thermal action. The surface of the reinforcement system is exposed to the action of different radiant heat fluxes (HF) equal to 35 [kW/m2] and 75 [kW/m2], from a cone calorimeter and the temperature variation measured by thermocouples placed between the surface of concrete and the CFRP. The influence of passive protection systems on the burning behaviour of CFRP is analysed using different fire protection materials, such as gypsum board (PB) and intumescent paint (IP). The temperature evolution between the different material layers is determined for the two heat fluxes, allowing to analyse the influence of these protective materials in the structural reinforcement capabilities of the CFRP when subjected to high temperatures. The temperature evolution results show that, for the tested cases, the gypsum board has a better performance than the intumescent coating.
With the increase of composite materials (FRP) applications new safety problems arise. Among these issues, there are concerns regarding their behaviour when exposed to fire. In case of direct exposure to fire, it is recommended that the FRP be applied using additional fire protection measures. An experimental programme was performed in order to evaluate the behaviour of composite materials when exposed to fire, in particular composite materials based on carbon fibres (CFRP). The materials used were the sheet and the carbon laminate fibre Therefore a campaign of tests (10 tests with sheet and 10 tests with laminate) on concrete specimens with 100×100×40 mm was developed. The CFRP sheet is glued on the surface of the specimens using epoxy resin and exposed to a thermal action. The surface of the reinforcement system is exposed to the action of different radiant heat fluxes (HF) equal to 35 [kW/m2] and 75 [kW/m2], from a cone calorimeter and the temperature variation measured by thermocouples placed between the surface of concrete and the CFRP. The influence of passive protection systems on the burning behaviour of CFRP is analysed using different fire protection materials, such as gypsum board (PB) and intumescent paint (IP). The temperature evolution between the different material layers is determined for the two heat fluxes, allowing to analyse the influence of these protective materials in the structural reinforcement capabilities of the CFRP when subjected to high temperatures. The temperature evolution results show that, for the tested cases, the gypsum board has a better performance than the intumescent coating.
Description
Keywords
CFRP Sistemas passivos Calorímetro Resistência ao fogo