Concrete Test Hammers are ideal for fast and economical nondestructive testing (NDT) assessment of in-place concrete strength consistency. These versatile concrete testing tools, also called Swiss Hammers or Rebound Hammers. Concrete rebount test hammers provide a rebound number, or R value, of hardened concrete. Rebound testing reveals areas of inconsistent quality, allows estimates of in-place compressive strength, isolates areas damaged by freezing or fire, and areas requiring more advanced NDT applications or coring.
Click the Concrete Test Hammer Comparison Table above to enlarge, print, or download. The table compares compressive strength and impact energy.
All models operate by pressing a plunger rod against a concrete surface until a spring-loaded mass is released, causing the plunger to impact on the concrete surface. On analog models, a sliding indicator shows rebound numbers. Advanced electronic versions use sensors and accelerometers for more repeatable R values. Included calibration curves provide estimated strength of concrete from rebound number. However, accuracy is greatly improved by user-produced laboratory correlations with compression tests on the same type of concrete being evaluated, as described in ASTM C805 and ACI 228.1R.