A proposal for the selection of mortars for use in the repair of historical buildings

Our country, which is home to many historic monuments and buildings that are still extant despite collapsing throughout the centuries due to various reasons, resembles an open laboratory. Therefore, it is important for historic buildings to be protected, repaired and reinforced in order to protect the universal cultural heritage. In this thesis entitled `A Proposal for The Selection of Mortar for Use in The Repair of Historic Buildings? aimed to propose mortar mixtures with different variations that are able to withstand environmental conditions. In the first part of the thesis, the problem is defined using existing studies on the topic and information is provided on the purpose, framework and methodology of the study. In the second section, the legal infrastructure involving the protection, repair and strengthening of historic buildings in Europe and in our country is discussed, and the sections of laws related to the protection of original materials are briefly explained. In the third section, materials used in historic buildings are explained briefly while the mortar and the materials used in its production are explained in detail with the subject of the study. In the fourth section, the factors that lead to damage in historic buildings are listed, with an emphasis on explaining the effect of the damage on mortar materials. In the fifth section, the experimental studies undertaken in structures and in the laboratory for the determination of the characteristics of the materials used in historic buildings are explained and examples of the studies undertaken are provided. In the sixth section, the program of the experimental study undertaken, the materials used in the production of mortar, preliminary experiments, production of samples, curing and aging processes used are explained. In this experimental study, 600 pieces of mortar samples with polyfibers or not as the variables are produced with siliceous sand and broken brick is used as an aggregate, lime, silica fume, fly ash, slag, brick powder is used as binding materials which have puzolanic properties. One series of these mortars was kept in a laboratory, while some others were left in the YTU main campus in atmospheric conditions in order to simulate the environmental impact. Another series of the mortar samples was classified into 6 groups representing freezing?melting in air, freezing?melting in the moisture cabin, getting wet in the sodium sulphate solution?drying in air, getting wet in the sodium sulphate solution?drying in the oven, getting wet in water drying in air, and getting wet in water?drying in the oven, and were subjected to amplified, expedited, separated aging effects. Before and after these effects, physical and mechanical control experiments were conducted in all samples. In the seventh section, the results from the control experiments explained in the sixth section are given with tables and graphs according to the aggregate, their durability processes and whether the mortar contained polyfiber or not as the variables. The addition of a certain amount of pozzolana materials to the lime mortar has enhanced the resistance and durability of the mortar and the addition of fiber has enhanced the resistance and durability to bending. Sulphate solution representing air pollution and increase in temperature were the factors that led to most damage. In the eighth section, the experimental study is elaborated on using existing research studies. Accordingly, mortar mixes are proposed that could be used in the repair of historic buildings in line with different climatic conditions. In the ninth section, the conclusions of the thesis are provided, and suggestions are made for other similar studies. Keywords: Historical Buildings, Repair, Durability, Khorasani Mortars, Lime Mortars, Puzzolanas