ASSESSMENT OF IN-SITU COMPRESSIVE STRENGTH IN CONCRETE STRUCTURES, METHODS AND CHARACTERISTICS

The new concrete standards give rules for in situ checking if the hardened concrete in structure achieved the designed compressive strength conforming to the request of class of concrete. Different concrete elements in structure request the different access during the examinations and different analytical analysis. Also the applied different methods will be the main aim on evaluations of concrete strength, always in comparing with requested design class. Core testing and other nondestructive methods assessing the strength of surface concrete are generally less reliable than cores, but less damaged will be used for final evaluations. Several parameters influence this property of concrete as the type and size of aggregates, cement type and content, placing the concrete, formwork parameters. To account for those factors in this paper we combine the measurements by taking the core samples and results with hammer Schmidt, ultrasonic or other alternative methods. Also the evaluations of compressive strength for different concrete elements in different positions/different layers/ will be the detail expressed in analytical form, because anin situ test is not possible to implement. Test selection for a particular situation will be based on a combination of factors such as access, damage, cost, speed and reliability, but the basic features of visual inspection followed by a sequence of tests according to convenience and suitability will generally apply.