STRUCTURAL RECUPERATION OF TWO METALLIC MARQUEES BELONGING TO TEATRO MUNICIPAL DO RIO DE JANEIRO (RIO DE JANEIRO OPERA HOUSE)

摘要

This article gives an account of the structural recuperation works effected on two metallic marquees belonging to Teatro Municipal do Rio de Janeiro, one of the city's most important buildings dating from the eclectic period. Inaugurated in 1909 in the wake of a radical reconstruction of the Brazilian capital's center which tore down the old colonial town to be replaced by a modern city modeled after Hausmann's Paris, the theater - freely inspired by the Garnier Opera - was totally built with imported materials coming from diverse origins: bricks, mosaics and ceramic tiles from Marseilles; cement from Antwerp or Le Havre; marbles from Italy; the metallic marquees came most probably from France. Located on the outside, above the major lateral entrances, the two marquees were in a very bad state of conservation when the works started, particularly due to inept recuperation procedures that have been carried out in the past. The diverse galvanic potentials that occur between the adjoining steel and cast-iron component parts and their respective welds was not taken into consideration. Decay had reached such a degree that the theater administration was forced to isolate the marquees for the safety of passersby. Recuperation procedures involved partial substitution of the old steel structure, restoration/conservation of cast-iron ornaments, cold-process galvanization of the ensemble and a final protective treatment. All recuperation processes used shall be herein described and the application techniques and problems regarding compatibility of materials, especially the one occurring between the anti-oxidizing agent and the finishing paint used, shall be discussed here as well. This paper will also focus on assessing the present state of said marquees two years after restoration, and on formulating practical conclusions directed to the community of conservators/restorers for future use when dealing with similar problems.