HGI maintains a fully equipped soils engineering and material testing laboratory utilizing state-of-the-art testing equipment to perform tests in accordance with the American Society of Testing and Materials (ASTM), the American Association of State Highway Officials (AASHTO), State of California Division of Transportation (CALTRANS), Uniform Building Code (UBC), or other applicable standards.

HGI provides in-house training by supervisors and engineering staff for each technician to understand and perform the tests to applicable standards.

Affiliations
HGI is currently participating in the Cement and Concrete Reference Laboratory (CCRL) Inspection Program, the CCRL Concrete Reference Sample Program, the AASHTO Material Reference Laboratory (AMRL) Laboratory Assessment Program, the AMRL Coarse and Fine Aggregate Reference Sample Program, and the CALTRANS Aggregate and Soil Reference Sample Program.

The State of California, Division of the State Architect (DSA) approval qualifies HGI to provide geotechnical engineering and construction observation and testing services for public schools.  Additionally, CALTRANS has qualified and approved HGI as a material testing agency.

Laboratory services provided include but are not limited to:

Soil Testing
• Atterberg Limits
• Soluble Chloride
• Chunk Dry Density & Moisture Content
• Consolidation
• Corrosion Analysis (pH, Redox, Electrical Resistivity)
• Direct Shear
• Expansion Index
• Gradation
• Maximum Dry Density / Optimum Moisture Content Relationship
• Moisture Content
• Organic Content
• Permeability
• Resistance Value (R-Value) 
• Ring Moisture Content & Dry Density
• Sand Equivalent
• Sieve Analysis (% -200)
• Soluble Sulfate
• Turbidity

Concrete / Masonry Testing
• Concrete Compressive Strength
• Grout Compressive Strength
• Mortar Compressive Strength
• Masonry Prism Dimensions & Absorption
• Masonry Prism Compressive Strength
• Masonry Core Compressive & Shear Strength

Hot Mix Asphalt Concrete Testing
• Asphalt Content (Ignition Oven)
• Hveem Specific Gravity / Stability
• Sieve Analysis
• Unit Weight of Core

Aggregate Testing
• Clay Lumps and Friable Particles
• Cleanness Value
• Durability Index
• Flat and Elongated Particles
• Gradation
• Length Change Due to Alkali-Carbonate
• Lightweight Particles
• Los Angeles Abrasion - Large Size Coarse Aggregate
• Los Angeles Abrasion - Small Size Coarse Aggregate
• Organic Impurities in Fine Aggregate
• Petrographic Examination Fine to Coarse Aggregate
• Potential Alkali Reactivity of Cement-Aggregate
• Potential Expansion of Aggregates from Hydration
• Potential Reactivity Mortar Bar
• Potential Reactivity of Aggregate - Chemical
• Potential Reactivity Rock Cylinder Method
• Potential Volume Charge of Cement-Aggregate
• Resistance Value (R-Value)
• Sand Equivalent
• Sodium or Magnesium Sulfate Soundness
• Specific Gravity and Absorption – Coarse Aggregate
• Specific Gravity and Absorption – Fine Aggregate
• Unit Weight of Fine / Coarse Aggregate

Reinforcing Steel
• Tensile Strength
• Bend Test