• American Association of State Highway And Transportation Officials (AASHTO)
  • GW² is currently participating in the AASHTO proficiency sample testing program and the AASHTO accreditation program (AAP). We hold current certificates of accreditation in the following areas:

    Hot Mix Asphalt - accredited since 4/12/2007
    T30 T166 T209 T269 T308 - D2726 D3203 D3666 D5444 D6307 E329

    Soil - accredited since 12/17/2003
    T87 T88 T89 T90 T99 T180 T193 T208 T265 T310 - D421 D422 D698 D1140 D1557 D1883 D2166 D2216 D2487 D2488 D2922 D3017 D3740 D4318 E329

    Aggregate - accredited since 12/17/2003
    T11 T19 T21 T27 T84 T85 T248 T255 - C29 C40 C117 C127 C128 C136 C566 C702 C1077 D3666 E329

    Portland Cement Concrete - accredited since 1/5/2004
    C31 C39 C42 C78 C138 C143 C172 C173 C192 C231 C1064 C1077 C1231 E329

  • Cement and Concrete Reference Laboratory
  • GW² has been sucesfully inspect by the United States Department of Commerce, National Institute of Standards and Technology, also we participated in their profiency sample programs

  • U.S. Army Corp. of Engineers
  • GW² laboratory and personnel have been inspected and approved as qualified to perform quality control testing as stipulated by Corps. of Engineers' construction regulations. Our Quality System meets the requirements of the U.S. Army Corps of Engineers and we are validated to perfom the foolowing materials tests:

    Aggregate Test:
    ASTM C40, C117, C127, C128, C136, C566 and C702

    Concrete Test:
    ASTM C31, C39, C138, C143, C172, C173, C192, C231, C1064, C1077 and C1231

    Soil Tests:
    ASTM D421, D422 ,D698, D1140, D1557, D1883, D2166, D2216, D2487, D2488, D2922, D3017, D3740 and D4318

    Masonry Test
    ASTM C109

  • Our entire field personnel is ODOT certified.