Quality Control/ Quality Assurance:
NTH’s Value Added
Our accredited laboratories and certified technical staff provide delivery of quick and reliable results that are validated through a formal in-house quality assurance and quality control program.
Construction Materials & Geotechnical Testing Services
A well designed and executed quality control and quality assurance program is vitally important to assure successful construction of a project. NTH maintains fully equipped geotechnical and construction materials testing laboratories.
Our extensive services include sample collection, field and laboratory testing, and preparation of closure certification documents.
Our professionals observe and test sub-grade preparation, installation of sub-grade drainage systems, placement and compaction of aggregate base course, placement and compaction of bituminous materials, and concrete materials.
We offer plant inspection, including calibration of the plant and testing of stockpiled material prior to the start of production. We monitor material handling procedures, mix proportions, mixing temperatures and mixing time during production, and sample the final mixtures to ensure conformance with project requirements and approved mix designs.
Laboratory Materials Testing
Our laboratory facilities have been inspected and accredited by the U.S. Army Corps of Engineers (USACOE). They comply with ASTM E329 and ASTM D3740 for agencies engaged in the testing and/or inspection of materials used in construction. In addition, our laboratories participate in the AASHTO Materials Reference Laboratory, and Cement and Concrete Reference Library (CCRL) programs. The NTH concrete laboratory staff is trained in the latest American Society for Testing and Materials (ASTM) and American Concrete Institute (ACI) testing methods.
Certified Technical Staff
More than 85% of our technical personnel are certified by the Michigan Asphalt Paving Association (MAPA), Michigan Concrete Association (MCA), American Concrete Institute (ACI), American Welding Society (AWS), American Society of Nondestructive Testing (ASNT), and other organizations.
NTH is prequalified with the Michigan Department of Transportation to provide comprehensive material, site inspection and testing services, as listed below: