Research on the Rebound Hammer Testing of High-Strength Concrete's Compressive Strength in the Xinjiang Region

Enhancing the assessment of compressive strength and the efficiency of rebound hammers in non-destructive testing for high-strength concrete is an urgent issue in construction engineering. This study involved C50 to C90 high-strength concrete specimens, utilizing rebound hammers with nominal energies of 4.5 J and 5.5 J, along with a compression machine. A regression analysis was performed on the compressive strength and rebound values, resulting in linear, polynomial, power, exponential, and logarithmic equations for two different types of rebound hammers. Additionally, the precision of rebound hammers with different nominal energies and the representativeness of various rebound representative values in the measurement area were investigated. The experimental results indicate that the precision of the regionally representative strength curve in Xinjiang meets national specifications. The 4.5 J nominal energy rebound hammer exhibited a higher testing accuracy. When reducing the high-strength concrete measurement area's rebound representative values from 16 to 14, 12, and 10, the coefficients of variation for the different rebound representative values were mostly below 10%. Within high-strength concrete structures, the strength curve formula derived from rebound representative value 16 is equally applicable to 14, 12, and 10. In practical engineering applications, prioritizing 10 ensures testing accuracy while reducing on-site testing efforts. The outcomes of this experiment establish a foundation for the development and promotion of rebound method-testing technology for high-strength concrete in Xinjiang.