Using Zorn Light Weight Deflectometers

A Light Weight Deflectometer (LWD) is a light weight portable tool used to determine the stiffness of unbound materials (subgrade/subsoils and base layers, granular layers & backfilling materials), or for stabilised material during construction or pavement rehabilitation.

Applications for this non-destructive method of testing include bearing capacity and compaction include road construction, pipeline and cable backfill, railway track beds, airport runway/taxiways, dam construction, embankments, foundations and other earthworks.

The LWD is used by construction companies and geotechnical engineering firms involved in pavement construction, pavement rehabilitation, construction material testing, geotechnical testing, pavement investigation and site investigation.

The results from LWD testing is used on behalf of road authorities, councils, asset managers, mines, mobile crane operations, engineering and construction groups, EPCM’s, subcontractors, geotechnical engineering consultancies and research organisations.

• Used for compaction control and bearing capacity estimation
• Unbound or partially bound layers (sub-grade, sub-base, base)
• Measures the deflection and stiffness (modulus)
• Immediate repeatable results so that on-site decisions can be made straight away

• Faster: immediate results using a tablet or smart phone and approx. three minutes per test.
• More accurate and repeatable: direct deflection readings and high levels of repeatability.
• Non destructive: surface based test with no footprint or disturbance of surface
• More representative: By measuring the modulus value, the LWD provides a link between design modulus value and the actual site condition (in-situ modulus value).
• Without errors: Data is automatically recorded from measuring equipment to report production. No manual data recording.
• GPS located and time-stamped: Immediately records test position integrated with Google Maps.
• Visually presented results: Data interpretation software allows data storage, analysis and manipulation with graphical outputs of results and easy inclusion into reports.
• Improved safety: Suitable for use in confined spaces and difficult to access locations.
• Cost effective: Lightweight and portable for one person operation. Suitable for locations where equipment/plant has to be stopped whilst the test is completed.

The Zorn LWD’s measures the dynamic modulus of deformation Evd in the range from 15 up to 140 MN/m².

Australian based geotechnical product sales and distribution company Insitutek proudly represents Zorn Instruments’ Light Weight Deflectometers (LWD’s) in the Asia Pacific region.

Insitutek provides a very high level of client support including product sales and training, technical repairs and parts.

Insitutek also manages the Australian based Calibration Service Centre exclusive to Zorn clients, saving significant down time compared to calibration and repairs overseas. Trilab is proud to be the exclusive Zorn LWD calibration service provider for Insitutek.

For more information, visit the Insitutek website Zorn LWD product page.

Watch the Zorn ZPG Light Weight Deflectometer videos