Characterization of the mechanical Properties of Historical Buildings Using Semi Destructive Methods; Case Study Historic Buildings of Nafisi, Sorkhehee and Kalantar in Tabriz

Each year a large number of historical building are destroyed by seismic events. Assessment of seismic vulnerability of heritage buildings has an important role on their conservation process. Identifying the mechanical characteristics of the materials used in constructions is one of the most important steps in seismic assessment, which is determined through destructive and semi-destructive tests. Due to the fact that destructive testing on heritage buildings is considered as kind of damage, Italian researchers have proposed a qualitative method called the masonry quality index (MQI) to estimate the mechanical properties of heritage building materials. In this article, the function of mentioned method has been used to estimate the compressive strength and modulus of elasticity of building materials in Nafisi historical house in Tabriz and the validation of the results has been compared with the results of double flat jack test. According to the comparison of the obtained results, the minimum and maximum compressive strength obtained by the MQI method in the range 3.89 and 2.29 MPa, while the compressive strength obtained by the flat jack test was in the range of 1.13 - 0.81 Mpa. Which indicates a high contrast. Also, the minimum and maximum values ​​of modulus of elasticity calculated by the masonry quality index (MQI) method are in the range between 1628.5 - 1137.06 MPa, which is compared with the results obtained by the double flat jack test between 1182.06 – 1382.27 MPa, showed a good agreement with each other. According to the results of compressive strength, it is necessary more studies are needed to apply the MQI (masonry quality index) method on native heritage buildings. It seems that in case of further studies, the method of masonry quality index can be adjusted appropriately with native heritage buildings and it can be used as a fast and safe method to estimate the mechanical properties of building materials.