Current condition of the exposed concrete façades reinforcement of the Vilanova Artigas building: modern architectural heritage

Abstract

The heritage of modern architecture in exposed reinforced concrete has been shown pathological manifestations affecting the structural safety and functionality of the buildings. The manifestations are, primarily, associated with the steel corrosion; however published data obtained from site surveys, on the Brazilian architectural heritage and related to the issue, are still scarce in the literature. Thus, the aim of the study is to assess the current condition of the exposed concrete façades reinforcement of the Vilanova Artigas building, a Brazilian architectural heritage, opened in 1969. Legal restrictions limited the destructive tests and sampling areas. The history of the interventions, environmental aggressiveness and preliminary inspection (in the parent concrete and patch repairs) provided qualified information for analyzing in situ testing results. In the sampling areas physical, chemical and electrochemical tests were carried out. The façades surfaces are naturally porous, irregular, with concrete segregation and corrosion products stains; 24% of the concrete was replaced with proprietary mortar repair. In patch repairs, the average carbonation depth ranged from 3 to 29 mm, in concrete it ranged from 15 to 30 mm. The reinforcement cover ranged from 8 to 33 mm. Corrosion potential maps, with equipotential lines drawn at 50 mV intervals, indicated the corrosion-prone areas, where there is a concentration of lines with a variation equal to or greater than 150 mV. The presence of corrosion products, detected in the visual examination of the reinforcement under the patch repairs, validated the active corrosion state. The rough surface of the concrete, the low cover to depassivated reinforcement and the active corrosion state emphasize the need for monitoring the façades and the urgency of implementing a preventive maintenance plan, along with a conservation project in order to preserve the heritage values of the building.

Sustaining modern heritage buildings: visual defect categorisation guides for the general condition survey of rendered-painted facades

“…platbands, exposed concrete with wood grain texture), while some others were abandoned (e.g. eaves, gutters, copings) (Tavares et al, 2012;Araujo et al, 2021;Marques et al, 2015;Stazi et al, 2012), etc. This innovative character was also reported in the aforementioned studies to be one of the causes of defects sometimes, some of which were specific to the detail and/or the technique used.…”

Avaliação da influência da corrosão na estabilidade global de colunas em concreto armado

“…However, the protection can be compromised with pH reduction to below nine due to the carbonation of the concrete. The carbonation process occurs due to the presence of chloride ions at critical rates of atmospheric pollution, which is intensified by the age of the construction (Maldonado-Bandala et al, 2018;Araujo et al, 2020;Silvestro et al, 2020). The use of inadequate cover thicknesses due to design or execution errors can compromise the protection of the steel bars (Fusco, 2008;Malheiro et al, 2014;Felix e Carrazedo, 2021).…”