Nelson Testing Laboratories is a construction materials testing firm in Schaumburg, Illinois USA. We specialize in partnering with our clients to provide reliable, prompt and practical solutions to construction material testing needs. Formerly known as Robert L. Nelson & Associates, Nelson Testing Laboratories (NTL) services international construction product and material suppliers through in-house laboratory testing according to ASTM, AASHTO and other appropriate test methods and specifications. NTL has been inspected and/or certified by AASTHO, CCRL and the Illinois Department of Transportation for concrete, aggregate and masonry testing.