ASTM adopts impact-echo standard

ASTM Committee C9 on Concrete and Aggregates has adopted the first standard test method in the world on the use of the impact-echo method for measuring the thickness of concrete pavements, walls, slabs, and other slab-like structures. The standard is an outgrowth of pioneering research performed at NIST in the mid 1980s and further refinement in the 1990s at Cornell University. The impact-echo method uses impactgenerated stress waves to detect the presence of internal defects (crack s, voids) in concrete, or it can be used to measure the thickness of a defect-free member. The method is being heralded by practitioners as one of the most significant developments in the last 15 years in the area of nondestructive testing of concrete.