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SEM image of concrete with the following composition: ordinary Portland cement CEM II 52.5 (EN 197-1:2000), naphthalene-based superplasticiser, river sand and crushed granite as fine and coarse aggregates, respectively, and a water-to-binder ratio of 0.3 (reproduced from [55]): (a) Magnification of 254; and (b) Magnification of 8131.
