Rebound Hammer Tests

Applicable On:

• Structural Concrete Elements (Slabs, Columns, Beams, Walls)
• Precast Concrete Units
• Tunnel Linings and Infrastructure Surfaces
• Aging Concrete in Repair and Retrofit Projects
• Concrete surfaces requiring quality screening prior to coring

Used To Evaluate:

• Uniformity of Surface Hardness and Relative Strength
• Preliminary identification of weakened or deteriorated zones
• Screening of delaminated or honeycombed areas
• Areas of non-uniform curing or poor consolidation

Key Benefits:

• Non-destructive, fast, and cost-effective
• Requires minimal surface preparation
• Ideal for field screening across large surface areas
• Helps prioritize areas for further investigation
• Provides immediate comparative data on concrete quality

Note: Estimated strength values derived from rebound numbers are affected by surface roughness, moisture content, carbonation, and material variability. Results are best used for relative comparison, not standalone acceptance criteria.

AEIS performs rebound hammer testing in accordance with the following standard:

• ASTM C805 / C805M–Standard Test Method for Rebound Number of Hardened Concrete (Used to assess surface hardness and estimate in-place compressive strength based on calibration curves.)

ACI Reference:

• ACI 228.1R-03–”In-Place Methods to Estimate Concrete Strength” Details the rebound number method, limitations, calibration procedures.

• ACI 228.2R-13– Section 3.3.1 Discusses estimation of compressive strength using rebound hammer with correction factors.

AASHTO Reference:

• AASHTO T 213– “Standard Method of Test for Strength of Concrete by Rebound Hammer” Equivalent to ASTM C805 and widely used in infrastructure testing.

All tests are conducted by trained personnel following standardized procedures, including taking at least 10 readings per test location and averaging results after discarding the two extreme values, as prescribed in ASTM C805.