Investigation with Non-Destructive and Destructive Methods for Assessment of Concrete Compressive Strength

Abstract

Determining the compressive strength of concrete is important in all phases of construction and in diagnosing the technical condition of existing reinforced concrete buildings and facilities during their service. In this article, the author presents the experimental results from research conducted over 6 years. The following non-destructive methods were used in the tests—elastic rebound, ultrasonic, SonReb and destructive methods, and the results of the latter were used as a reference. The tests were carried out on specimens prepared on the day of laying the concrete mix in the reinforced concrete beams or cores taken from the beams. The results of the determination of the probabilistic compressive strength using the different methods at concrete ages of 28, 244, 280, 293, 342, 1126 and 1926 days, are presented. The relative error, predicted strength and accuracy were determined and compared. Isocurves were drawn to determine the compressive strength for each point of a reinforced concrete structure based only on measurements obtained using non-destructive methods. The results obtained via SonReb and via the method assessing ultrasonic pulse velocity and its relationship to the dynamic and static modulus of elasticity were the closest to the reference compressive strength values.