Constructed soils are Technosols resulting from the deliberate combination of various technogenic materials to restore derelict lands. The efficiency of the brownfield reclamation relies on the sustainability of the constructed Technosols and therefore requires studying their early pedogenesis. The present work focuses on the evolution of their structure at different scales. Two soils were constructed in lysimetric plots (10 x 10m x 1 m depth), using a soil engineering process by the association of paper-mill sludge, thermally treated soil material, and green-waste compost. The evolution of the soil profiles was studied in situ for 3 years. It consisted in the confrontation of i) the observation and description of the macro-structure organization, ii) the texture, iii) the stability of aggregates, iv) indirect measurement of the porosity thanks to pressure-plate methods and v) observation at ultrastructural scale of 0-50 μm organo-mineral fractions. The first result is the horizonation of both soil profiles with the differentiation of the initial layers in new soil horizons. Then, the structure of the soils evolved by global compaction and by the change of the porosity distribution. At a smaller scale, mechanical and biological aggregates formation was described and an increase of the aggregate stability with time was measured. Intrinsic reasons relating to the technogenic parent materials origins inevitably induce a remarkable intensity in the pedogenic processes of constructed Technosols. Disequilibria between the parent materials and the environmental forcing factors lead to a fast and original pedogenesis, certainly peculiar to Technosols.