GRL Engineers, Inc. Shaft foundations Gamma Gamma Logging Service Non-destructive testing concrete integrity Concrete curing PVC tubes core holes Gamma radiation bulk density

GRL Engineers New Gamma-Gamma Logging Service Sponsored

*The Gamma-Gamma Logging (GGL) test method*

GRL Engineers is now offering Gamma-Gamma Logging Service (GGL) in the United States.

Gamma-Gamma Logging is a non-destructive test method used to assess the concrete integrity of drilled shafts through gamma-density correlation.

It is a testing procedure that can be conducted quickly and provides highly repeatable test results, while objectively evaluating the integrity and relative concrete quality inside and outside of the reinforcing cage.

PVC access tubes (2 in/50 millimeters in diameter) are attached to the steel reinforcing cage before concrete is poured in the excavation. Nevertheless, if testing was not initially planned, an engineer can perform GGL by using core holes drilled through the concrete.

The GGL test probe has a low-level radioactive source (Cesium-137) at its tip and a shielded detector located 15 in (38 cm) away to assess the concrete density surrounding the access tubes or core holes. The 4 ft (1.2 m) long GGL probe is lowered into each access tube using an electric winch.

Gamma radiation counts, in counts per second (CPS), are logged as the probe is raised at a typical rate of 10 ft (3 m) per minute. GGL assesses the bulk density of the concrete from the center of the access tube outward for a radial distance of about 3 in to 4 in (76 mm to 101 mm) using the low-level energy source. Based on the calibration data, engineers can present profiles of the average bulk density in pounds per cubic foot versus depth.

For more information about the Gamma Gamma Logging Service, you can visit GRLengineers.

Source: Pile.com