Heritage Days :  on the occasion of the Journées du Patrimoine on Saturday 16 and Sunday 17 September 2017, the Palais d'Iéna will open its doors and exhibit photos on its gates. I have the honor of attending :  the theme will be devoted to its restoration, completed last October.
 
Built by Auguste Perret between 1937 and 1946, universally recognized, classified Historic Monument, the Palais d'Iéna represents a monument of classical order with perfect proportions, slender columns and remains an absolute ideal "of aesthetic perfection". The concretes are composed of green porphyry and pink marble, uncoated – "the concrete is self-sufficient" – chiseled like stone, with edgings highlighting the architecture.
 
 

 
The degradation of concretes due to weather and pollution, as well as the phenomenon of carbonation required a restoration of precision.
The restoration of the concrete facades of the Palais d'Iéna (Social and Environmental Economic Council) was carried out by PIERRENOEL and FREYSSINET and was completed in October 2016.
It involved cleaning, analysis of old concrete, formulation of replacement concrete, concrete work in an artistic way and finishing according to the methods of Auguste Perret so that all restorations remain undetectable.