Abstract:

In the present paper the relation between the laboratory results of schmit hammer test on cube samples and the pressure strength of the same sample, and subsequently the relation between the results of schmit hammer test on concrete structure and the pressure strength of cube samples taken from the concrete of the same structure, have been investigated. The ralation between the strengh of 7d concrete and 28 day concrete is investigated and evaluated. The results show that there is a significant correlation in the form of a linear second grade equation with a correlation ratio of 78.4% between the resiliance level of schmit hammer and the pressure strength. Therefore the results of Schmit hammer test can be used to determine the concrete strength of structure as a non destructive test, investigate the uniformity of strength in different parts of the structure and also deciding when to remove forms or putting the structure under application conditions. Also the pressure strength of 28d concrete can be estimated with a considerable certainty ratio, using the results of pressure strength of 7d concrete