Author's personal copy Progress in Organic Coatings 72 (2011) 202–209 Contents lists available at ScienceDirect Progress in Organic Coatings j ourna l ho me p ag e: www.elsevier.com/locate/porgcoat Reverse engineering methodology for studying historic buildings coatings: The case study of the Hellenic Parliament neoclassical building M. Karoglou ∗ , A. Bakolas, N. Kouloumbi, A. Moropoulou National Technical University of Athens, School of Chemical Engineering, Zografou Campus, 15780 Athens, Greece a r t i c l e i n f o Article history: Received 16 September 2010 Received in revised form 18 January 2011 Accepted 22 January 2011 Keywords: Polished plasters Diagnostic campaign Crushed stone colouring a b s t r a c t In this work a reverse engineering methodology for the study of historic buildings coatings is presented. This includes different stages: characterization and evaluation of historic coatings, criteria and method- ology for the selection of raw materials and the production of restoration coatings, criteria and procedure for the evaluation of restoration coatings and evaluation of coatings during setting and hardening. The proposed methodology was applied for the study of the Hellenic Parliament building. More specifically in order to recognize and map the original historic coating non destructive techniques were used, such as fibre optics microscopy, infrared thermography, ultrasonic technique and ground penetrating radar. The chemical composition of the original coating, its decay and its production technology, were assessed by granulometric and thermal analysis, as well as by X-ray diffraction. Additionally the colorimetric values of the coating were assessed, using the L*a*b* colour space. It was found that the colourization resulted by a crushed stone, used as aggregate, without the addition of any pigments. Based on these data, various compositions of restoration coatings were prepared and tested. Their evaluation was performed based on compatibility criteria with the historic coating. © 2011 Elsevier B.V. All rights reserved. 1. Introduction In this work a reverse engineering methodology for the study of the historic coatings of the Hellenic Parliament is presented. Addi- tionally new coatings are proposed for the restoration of buildings fac ¸ ades. Hellenic Parliament building is a neoclassical three-floor struc- ture, designed by Friedrich von Gärtner in 1843 (Fig. 1). The construction works were completed in the period from 1836 to 1840 and the building initially served as King Otto Royal Palace. After suffering fire damage in 1909, it entered a long period of ren- ovation. The building was then used for many different purposes – functioning as a hospital and a museum, among other uses – until November 1929, when the government decided that the building would house the Parliament. The works for the modification of the Old Palace started in the summer of 1930. The building houses the Parliament since 1935, with only few exceptions during the dicta- torship of Metaxas, the German conquest and the coup that was staged by junta (stratocracy) on April the 21st, 1967 [1–3]. ∗ Corresponding author. Tel.: +30 2107721432; fax: +30 2107723215. E-mail addresses: margo@central.ntua.gr (M. Karoglou), abakolas@central.ntua.gr (A. Bakolas), koni@chemeng.ntua.gr (N. Kouloumbi), amoropul@central.ntua.gr (A. Moropoulou). Concerning fac ¸ ade coatings, the authentic materials of 1840, were totally removed in 1930 restoration. The materials of 1930 are now considered as the original materials of the building. In 1966, the facades were cleaned with the use of a rotary abrading tool. During the period of 1985–1986 extended reparation works at buildings facades took place. The new materials used at that time were white cement based plasters with marble dust, polymer addi- tives and inorganic pigments. The original coating materials have been deteriorated by natural weathering, by the corrosive action of polluted atmosphere of the city centre and by the successive interventions with improper materials, such as the extensive use of cement and polymer-based materials. Hellenic Parliament building except its architectonical value carries ideas and ideals, which are registered in Greeks collective unconscious as powerful landmarks and symbols. The restoration of this building is strongly connected with Greece modern history and collective memory. Thus the restoration of buildings fac ¸ ade coatings according to historic preservation principles is more than a necessity. Plasters used in historical buildings, served as coatings, pro- vide important and helpful information about building technology of their historical period [4]. In Greece, the art of masonry and mortars flourished from the ancient years to Byzantium. A variety of hydraulic mortars have been studied by the Materials Science and Engineering Department, of National Technical University of Athens [5,6]. This led to a methodology for the production of 0300-9440/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.porgcoat.2011.01.008