lab 1 EDITEDDuffield Associates operates two of the Mid-Atlantic region’s largest privately owned construction materials testing laboratories.  These extensive facilities combine a full range of testing equipment with isolated and conditioned environments required for precise test protocols. Our full-service soils and concrete testing laboratories, complete with environmentally conditioned rooms for the storage and curing of concrete compression test cylinders, are accredited by the American Association of State Highway and Transportation Officials (AASHTO) and our Wilmington, Delaware lab testing procedures are validated by the U.S. Army Corps of Engineers. Our geosynthetics testing laboratory has serviced solid waste industry clients for over 20 years.