Restoration intervention of exposed white concrete buildings: The case of ‘Pavilhão do Conhecimento’, Portugal

Abstract

In the restoration of exposed concrete buildings with architectural or cultural relevance, the chromatic and texture compatibility between the adopted repair mortars and the original concrete surface plays a key factor. In the particular case of smooth white concrete surfaces, this compatibility can be even more challenging. The application of commercial products ensures mechanical aspects, but the aesthetic matching between both materials is hard to achieve. A methodology for restoration of smooth exposed surfaces of white concrete is herein presented. The concrete surface is chromatically characterized by image processing, and then a customized restoration mortar is designed by adding pigment to a reference mortar, defined to fulfil mechanical and durability requirements. The methodology was validated in ‘Pavilhão do Conhecimento’, the first building in exposed white concrete built in Portugal. The chromatic and finishing compatibility was achieved, and the interventions are not perceptible to the human eye. The developments proposed results in a science-based approach that enable the reproduction of smooth white concrete surface finishes and the chromatic reintegration to replicate colour heterogeneity and soften the transition zones.