Coauthored Publications with: Marques

Conference Proceedings

Marques, JL, Fong P, Macedo P, Chastre Rodrigues C, Lúcio V.  2004.  Comportamento da Ligação CFRP-Resina–Betão Sujeita a Acções Cíclicas. Betão Estrutural 2004. , Porto: FEUP Abstractmarques2004fomachlu_-_be2004.pdf

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Journal Article

Marques, PF, Chastre C.  2012.  Performance analysis of load–strain models for circular columns confined with FRP composites. Composite Structures. 94:3115-3131., Number 11 Abstractmarques__chastre_2012.pdfWebsite

The use of FRP composites for the confinement of concrete has become an important aspect to consider on strengthening of concrete columns. It is important therefore that accurate modelling tools are available for the design of this system considering, not only the peak values of load and strain, but also the complete stress–strain behaviour. A wide group of authors have proposed several models specific for FRP-confined concrete based either on theoretical assumptions (analysis-oriented-models – AOMs) or on mathematical calibration from testing results (design-oriented-models – DOMs). This article carries out the implementation and analysis of nine existing models for circular concrete columns in view of axially tested reinforced concrete columns confined with CFRP with three different diameters: 150; 250 and 400 mm. The global shape of curves, peak compressive load, stress–strain relation, axial-to-lateral relation and dilation response were studied to conclude which models’ curves were closer to tests. Quantification of errors in face of the testing results was carried out for the most important parameters – ultimate load, strain and lateral stress – as well as for other curve parameters. Some models are accurate in predicting the peak load, though only few can accurately predict the load–strain and dilation behaviour.
Marques, PF, Chastre C, Nunes Â.  2013.  Carbonation service life modelling of RC structures for concrete with Portland and blended cements. Cement and Concrete Composites. 37:171-184. Abstractmarques_chastre_et_al._2013.pdfWebsite

The presented work aims at studying the modelling of long term performance of concrete compositions with different proportions of clinker as regards the diffusion of CO2 in concrete – carbonation. The replacing constituents of clinker that will be part of the binder in each concrete composition are limestone filler and low calcium fly ash (FA). The used percentage of FA by weight of binder was of 50%. Concrete compositions were made following standard prescribed requirements to attain service lives of 50 and 100 years as regards concrete performance against reinforcing steel corrosion. Test results of compressive strength and carbonation depth are reported at different curing ages of 28, 90, 180 and 365 days. Carbonation results were used for the implementation of modelling equations in order to estimate the design service life regarding reinforcing steel corrosion. Two performance-based methods were used: safety factor method and probabilistic method, and their results compared with the traditional prescriptive approach. At the age of 28 days the composition with OPC is the only one that reaches the target periods of 50 or 100 years. For the probabilistic method, different curing age results were analysed. For the tested results at 90, 180 and 365 days of age the reliability of some of the compositions with blended cements is within the minimum required, although still far from the higher performance of concrete with OPC.