Ecoceramics (environmentally conscious ceramics) are biomimetic/biomorphic ceramics, which use a naturally occurring and sustainable material as a template for their unique morphology and structure. Usually woods (or lignocellulosics) are used, due to the inherent cellular nature of their microstructures. The wood is pyrolised and the resulting carbon skeleton impregnated with a fluid, and this is then heated to combust the carbon template and convert the fluid precursor into a ceramic, while maintaining the structure of the original natural template. For the first time, ecoceramics have been made from cork, a totally sustainable wood that is harvested without harming the tree. Also for the first time, ecoceramics have been made of soft magnetic Z-type hexaferrites, in this case the room temperature multiferroic strontium Z ferrite Sr 3 Co 2 Fe 24 O 41 (SrZ). Cork powder was pyrolised at 1000°C, infiltrated with an aqueous sol-gel SrZ precursor, and then heated at 1200°C/2 h to produce the ecoceramic. The cellular structure of the cork was maintained, with a small reduction in the hexagonal cell dimension to 10 lm diameter, but the cell walls remained 1-2 lm thick, of a similar magnitude to the hexaferrite grain size. Both magnetic and XRD data agreed that there was a small portion of the SrW phase present in these ecoceramics as well, and the magnetic loop showed a magnetically soft ecoceramic with M s = 59.5 A m 2 kg À1 (at 3 T), and a low H c of 16 kA m À1 .
A vulnerabilidade das estruturas de concreto armado pode estar associada a alguns pontos de fragilidade. Objetivou-se avaliar o efeito de espaçadores na corrosão da armadura desencadeada por carbonatação. Corpos de prova de concreto armado foram submetidos à ensaios de indução da penetração de CO2, velocidade de onda ultrassônica, profundidade de carbonatação e perda gravimétrica da massa das armaduras. Identificou-se que os corpos de prova com espaçadores de argamassa industrializada foram os que mais apresentaram indícios de corrosão. Esse estudo limitou-se ao cobrimento da armadura de 2,5cm, entretanto, realizadas de forma ampla e diversificada. Os espaçadores influenciaram a entrada de CO2, favorecendo a despassivação e perda da massa gravimétrica das barras de aço.
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