Construction Materials Testing (CMT) minimizes surprises by providing in-depth data to help make informed decisions about a project. Whether it is residential, commercial, or federal, our highly-trained engineers and technicians specialize in testing a full range of construction materials and processes.
Shield regularly provides CMT services such as:
- Earthwork Monitoring
- Soil Density Testing
- Foundation Monitoring
- Structural Steel
- Foundation Bearing Verification
- Reinforcing Steel Verification
- Concrete Testing
- Structural Masonry
- Seismic Site Classification &
Refraction Microtremor (ReMi) Testing
- Inclinometer Measurement Services
- Floor Flatness & Levelness Testing
- And more
Seismic Site Classification
Our experience in permitting is a cornerstone of our capabilities. Along with completing permit applications or Notices of Intent, Shield is capable of water quality modeling for Total Suspended Solids (TSS), metals, volatiles, and other industry benchmark standards.
Site soil conditions are important in determining Seismic Design Category. Site Class is determined based on the average properties of the soil within 100 feet of the ground surface. Geotechnical engineers use a variety of parameters to characterize the engineering properties of these soils, including general soil classifications as to the type of soil, the number of blows (SPT-N) needed to drive a standard penetration tip 1 foot into the soil, the velocity (Vs ) at which shear waves travel through the material and the shear resistance of the soil (Su ) as measured using standard laboratory test procedures.
The table below lists the six Site Classes recognized by the NEHRP Recommended Seismic Provisions and the engineering parameters used to define them. On many sites, the nature of soils will vary with depth below the surface. The NEHRP Recommended Seismic Provisions permits sites to be categorized as Site Class D unless there is reason to believe that the site should be downgraded to Site Class E or F. Classification of a site conforming to Site Class A, B, or C generally will lead to a more economical structural design than assuming site Class D; however, in order to achieve a higher rated Site Class (A, B, or C) additional testing of the soil stratum is recommended.
Table: Site Class and Soil Types
Refraction Microtremor Testing
ReMi is a seismic surface wave testing method that is used to aid in seismic site classifications. ReMi method uses ambient noise and surface waves to generate a detailed vertical shear wave velocity (Vs) profile of soil stratums up to 300 feet in depth.
The ReMi test setup includes a linear array of multiple equally spaced geophones established inserted into the soil and connected at one end to a seismograph. The length of the array depends on the depth of investigation; in order to obtain information to 100 feet a length of 300 feet or more is typically required. Once the array geophones are established, the seismograph records both ambient and active noise within the area.
After information is collected and interpreted, the end product is a one-dimensional column of shear wave velocity variation for each seismic line established at a site.
The ReMi method is capable of detecting thin layers and velocity inversions, and is highly reliable and commonly used method for earthquake design and seismic site classification determinations. The ReMi method is particularly effective in noisy environments, which are ideal for shear wave profiling in urban environments where other seismic testing methods are not applicable due to large amounts of ambient noise.
Inclinometer Measurement Services
Inclinometers are typically installed vertically into soil subsurface and are used to monitor horizontal subsurface movement and deformations. An inclinometer has two components: (1) inclinometer casing and (2) an inclinometer measurement device.
Inclinometer casings are installed in a borehole below ground surface to a pre-determined depth. The casing provides access for subsurface measurements. Grooves inside the casing control the orientation of the inclinometer sensor and provide a uniform surface for measurements. Vertical installation of inclinometers are used in a variety of applications including but not limited to:
- Landslide Investigations
- Monitoring Slope Stability
- Monitoring Retaining Walls
- Monitoring Excavations near Facilities
Less common are horizontal installations of inclinometers. Horizontal installations typically utilize a specialized probe to monitor settlement.
- Monitoring Settlement of Embankments
- Monitoring Deformation of Pavement
Floor Flatness & Levelness Testing
Floor flatness (FF) can be associated with the bumpiness of the floor surface and is primarily affected by the finishing operations. “FF” numbers extend from zero to infinity so the higher the FF number, the flatter the floor.
Floor levelness (FL) controls the departure of the floor surface from the specified slope or plane of the surface. “FL” numbers evaluate the elevation differences along a sample line at certain intervals. The higher the FL number, the more level the floor is considered.
Floor flatness and levelness testing should be performed per ASTM E 1155 “Standard Test Method for Determining FF Floor Flatness and FL Floor Levelness Numbers.” Flatness and levelness readings should be measured as soon as possible, preferably within 24-hours after concrete placement. With the passage of time, joints and cracks curl making the floor less flat. Typically flatness and levelness testing is performed to verify the contractors work has been performed to specification. If you are unable to make a measurement within the specified time frame, FF and FL numbers may not represent the true performance of work.
Shield offers specialty testing on floor flatness and floor levelness. Our technicians and engineers are trained to evaluate flatness and levelness for slabs-on-ground and suspended slab surfaces.
Construction Quality Assurance
Construction Quality Assurance (CQA) ensures the quality and fidelity of a project from the very beginning by working with each team to develop quality benchmarks, best practices, and on-site quality commitments for the duration of each job. Whether a project is facing design changes or actionable quality goals need to be set, the experienced team at Shield is ready to help
Construction Quality Control
Construction Quality Control (CQC) ensures compliance with standards of material and workmanship to keep the performance and longevity aligned with design expectations. Shield provides CQC on a variety of construction projects including private, municipal, and federal. Our skilled and experienced technicians provide reliable test results and consistent project management, making Shield a preferred partner in the construction field. Our staff of professional engineers, geologists, scientists, and technicians have over 100 years of combined experience. When working with our industry-leading construction and soil liner inspection team, Shield has worked with over 200 CQC construction projects across the United States