A preliminary study on the conservation and polishing performance of Sanliurfa limestones as a traditional building material

Sanliurfa limestones have been used as building materials from antiquity to current day (e.g., Gobeklitepe temple B.P. 14,000, Bazda underground quarries B.P. 3000, Harran castle B.P. 3000, etc.). These antique structures are listed within the United Nations Educational, Scientific and Cultural Organization (UNESCO)’s World Heritage List. However, the stones were used in these structures without any protection, and atmospheric conditions (precipitation, acid rain, temperature changes, etc.) cause damage to these stones over time, such as strength loss, abrasion, and discoloring. The damage can lead to the collapse of precious historical structures, or may require costly restoration. In this study, Sanliurfa limestone was investigated with respect to conservation using polish insulation (polysiloxane, lithium silicate, and varnish), appearance performance by polishing, and potential usage in the marble industry. The results revealed that conservatives could maintain up to 92 % of the unconfined compressive strength (UCS) of the natural stone and reduced acid abrasion to 0.5 % of the original weight. The stone gained a bright appearance after polishing, especially by lithium silicate. Thus, it can be stated that it is possible to recover or prolong the lifetime of the monuments that were constructed using Sanliurfa limestone, and this limestone may have great industrial potential as marble stone.