INVESTIGATION OF ENGINEERING PROPERTIES OF FLY ASH SUBSTITUTED CONCRETE WITH NON-DESTDUCTIVE TESTING METHODS

In this study, determination of the engineering properties of concrete having fly ash by non-destructive test methods is aimed. In the experimental study, test specimens were prepared using F type fly ash obtained from Orhaneli thermal power plant in the rates of 0-5-10-20 and 30%. Twelve numbers of cubic samples having 15x15x15 cm dimensions were obtained from the five different concrete mixes. Surface hardness, pull-off tensile strength test, ultrasonic pulse velocity test and compressive strength tests were performed on the concrete samples after the 28th days cure conditions. According to the non-destructive test results, concrete compressive strength values were calculated by using various empirical equations. Calculated compressive strength values and the experimental compressive strength values were compared with each other using statistical methods. As a result, experimental concrete compressive strength values have been determined among 18-33% error rates by using proposed equations in the literature. Experimental concrete compressive strength values have been determined with a low error rates with proposed empirical equations. It was showed that developed empirical equations in this study could be used to estimate compressive strength of the fly ash substituted concretes.