IRAQ - Stabilization and Conservation of Minaret Choli, Erbil

 konzervace choli 2009 tab

Minaret Park, Erbil, Iraq
Description of work: Stabilization and Conservation of Minaret Choli in Erbil

Ministry of Tourism and Heritage of the Kurdistan Regional Government, Iraq
04/2008 - 05/2009












Minaret prior to the start of works Minaret scaffolding was erected Conservation works started Restoration of the decorative strip Injection of the outer shell Repointing of joints Structure strenghtening by helifix system Top of the minaret before treatment Top of the minaret roofed by copper Replacement of damaged bricks and wall strenghtening Night lighting system instalation Placing of  the eastern gate bars Hydroizolation of surrounding area Minaret after end of the works Detail of the minaret Minaret after end of the works konzervace_choli_2009_tab Minaret at night

  The Capital of Kurdistan region of Iraq has extraordinary long history. Erbil's first historical record (as"Urbilum") is in Sumerian text from the end of 3rd mill. BC. Choli minaret is dated to the Atabeg period (12th Century). The structure was built from low burnt bricks and gypsum based renders and mortars. Due to the long term effect of deterioration, the essential part of the architecture has disappeared and thus the leaning minaret is the last survival of the past mosque. Project "Conservation and Stabilization of Choli Minaret in Erbil" was realized in accordance with the contract between GEMA ART GROUP a. s. and the Ministry of Tourism and Antiquities of the Kurdistan Regional Government.

  Based on the results of the general assessment of the whole monument carried out in 2006 all conservation and stabilization processes were provided. The policy of intervention was kept in terms of pure conservation of the historic landmark. The stabilization of the whole structure and conservation treatments of all surfaces were carried out without the tendency to reconstruct missing and unknown parts of the minaret. The only exception was the area of lower niches where pure conservation would be confusing from the architectural point of view. The inside area of all niches has been covered by mortar imitating the under layer for ceramic tiles. All remaining original parts were carefully consolidated and retouched. The inner vaults of niches were reconstructed to its original shape to make the architectural frame better identified.
  The main task of the project was to implement the entire static masonry reinforcement of all walls and then to re-connect the internal body with external shell. The principal components of the system were spiral stainless steel rods HeliBars made from austenitic stainless steel XCrNi 1810. Bars were of different length and cross-section depending upon the application, which were bonded into cut slots at pre-determined levels in the masonry using thixotropic cementitious grout HeliBond MM3.
  The conservation treatment of masonry covered repointing of all joints in the entire brick structure, consolidation and restoration of fragments of both ceramic and gypsum decorations including color and plastic retouching. The interior of both staircases has been rehabilitated. Bricks that have been deteriorated to the extent of losing their stability were replaced. Bricks for substitutions were produced according to the historic technology in the specialized brick workshop with the respect to the historic ratio of raw materials. All refilling materials followed the results of the research of ancient materials and were based on modified alpha-gypsum system with silica sand as a main aggregate. Last remaining stucco architectural parts that were in acute danger of collapsing were re-attached back to the core of the minaret. Subsequently, all open spaces, crevices and cracks were thoroughly filled in with the modified gypsum based filling material. The drained circle around the minaret was paved by replicas of historic low burnt brick tiles called "farshi" additionally consolidated by ethylsilicates.