Durabilidade de estruturas de betao armado em ambiente maritimo

This work is related with the durability of concrete structures, aiming at the study of the behaviour of this type of structures in marine environment. The marine environment was characterised, the deleterious agents were identified and the basic exposure zones and their aggressivity were described. The main deterioration mechanisms were characterised as well as their relevance to the durability of the structures. A practical example of a marine construction was presented where the causes and consequences of the deterioration mechanisms were assessed and illustrated. The chloride penetration and carbonation in reinforced concrete elements exposed to the marine environmental in several exposure conditions were studied. The transport mechanisms were modelled to allow the prediction of long term chloride concentration and carbonation in concrete. The code requirements for concrete structures exposed to the marine environment were analysed and their effectiveness was evaluated in the light of the experimental results obtained. The concrete properties directly related to the durability were analysed. Several laboratory tests were performed: porosity, porosimetry, petrographic and microscopic analysis, resistance to penetration of chlorides, resistance to carbonation, absorption, water permeability and compressive strength. The measured properties were used to assess the performance of the concrete elements exposed to the marine environment. The problems related to service life prediction of marine structures were analysed and the main aspects with the initiation and propagation were describedAvailable from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1200 Lisboa / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga