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Most of the methods for estimating the strength are either destructive or have expensive and imported equipment. Some of them also indirectly measure the strength. Therefore, a test that has cheap, simple and available equipment, with high accuracy, can be applied in all conditions, has minor damage and can be performed both in the laboratory and on the project site, it is required. Therefore, in this article, the compressive and tensile strength of different mortars and stones have been measured using a in-situ method with cheap and available equipment called "friction transfer" test. In this test, first a partial core with a diameter of 50 mm is created on the surface of the sample, and then the friction transfer device is fixed on the core and using a normal torque meter, a torsional anchor is applied to the core until it fails. be made Then, by determining the surface resistance obtained from the friction transfer test and comparing the obtained results with standard tests, the equations obtained to convert the results from the "friction transfer" test into the uniaxial compressive strength of the materials are presented. Tests were performed on seven different types of stone and cement mortars that are used in normal repair works. The obtained results show the high accuracy of the friction transfer test in measuring the strength of stones and mortars. The coefficient of determination between the results of the friction transfer test and the uniaxial compressive strength of the stones was found to be 93.2%, and according to the calibration curve, by using the friction transfer test, the compressive strength of the stones can be determined using the equation y=1.67x+90.8 measured. Also, by using the friction transfer test, the compressive and tensile strength of mortars can be measured with an accuracy of about 94%.

Despite the fact that in most operating conditions, concrete components, compaction and curing affect the performance of concrete, but premature failure of concrete structures due to problems with the durability of concrete structures also occurs a lot. Due to the lack of information on the effect of type and strength of aggregates on the durability of self-compacting concrete, in this article, using the tests of "friction transfer" and "drilled core" to investigate the effect of strength of different aggregates on the reliability of concrete Self-compacting has been exposed to sodium sulfate. 9 types of stones with the names of travertine, granite, basalt, andesite, marble, green stone tuff, crystal green tuff, rhyolite and limestone have been used to make self-compacting concretes. Compressive strength tests of self-compacting concretes cured with water and sodium sulfate solution were performed at ages 7, 14 and 28. The results showed that the volume change of rocks with higher water absorption percentage was less and there is a direct relationship between the compressive strength of self-compacting concretes treated in water and sodium sulfate solution with the strength of the parent rock. We also see an increase in compressive strength of self-compacting concrete placed in sodium sulfate solution at a young age compared to samples placed in water. There is also a linear relationship with a high correlation coefficient between the results of the friction transfer test and the core correction test. Compressive strength of crystalline green tuff, green tuff, andesite, rhyolite, travertine, lime, marble, granite and basalt are 31.76, 33.12, 39.92, 43.43, 48.41, 51/97, 59.66, 62.17 and 75.41 Mpa, respectively. With increasing compressive strength, the results of friction transfer test also increased so that for the mentioned rocks are equal to 132.4, 146.9, 155.9, 168, 176.3, 185.3, 189.8, 5 / 198 and 9/207 Nm.

In engineering works, especially in geological sciences, civil engineering and mining engineering, before or after the construction of structures, there are cases where it is necessary to determine the strength of stone or concrete. In this regard, changes in the use of the structure (change in load), unfavorable operating conditions, lack of time, lack of access to laboratory equipment and structural damage are among the reasons for assessing the strength of materials in situ. There are several methods for testing materials that are either destructive or have expensive and imported equipment. In this paper, using the new "Twist-off" test, the strength of 9 different types of stone and concrete with eight different strength classes has been measured. Also, while comparing the results with standard methods, calibration diagrams and equations required to convert the results of the "Twist-off" test to the compressive strength of the mentioned materials are presented. According to the results, to measure the compressive strength of ordinary concrete using twist-off test, the relationship y = 19.27x0.67 with a coefficient of determination of about 0.95 can be used. Also, for the rocks used in this research, by using the equation y = 27.87x0.52, the compressive strength of the mentioned rocks can be determined by using the twist-off test with an accuracy of 94%.