The ZFG 3000 Light Weight Deflectometer (LWD) from Zorn Instruments is used for measuring the bearing capacity (deflection) of subgrade/subsoils and unbound base layers, granular layers & backfilling materials, according to ASTM E2835-11 and ASTM E2583-07 (2011).

Using extensions to the ZFG 3000, dynamic CBR (California Bearing Ratio) can be measured in-situ in the field and also laboratory CBR in a cylinder can be simulated.

The ZFG 3000 LWD is suited for coarse-grained and mixed-grain soils and can be applied to determine the dynamic modulus of deformation Evd in the range from 15 up to 105 MN/m². Experimental investigations show a measuring depth to 60 cm.

In addition, an optional GPS-System allows the user to immediately determine and record the test position and this is integrated with Google Maps.

Applications for this non destructive method for testing bearing capacity and compaction control include flexible pavements, unsealed roads and mine access roads, tunnels, railway track beds, airport runway and taxiways, hard standing areas, dam construction, canal building, embankments, mobile crane foot standing pads (outriggers), building foundations, pipe laying and tank farms.

Clients include those involved in pavement construction, pavement rehabilitation, material testing, geotechnical testing and site investigation and include road authorities, councils, asset managers, mines, mobile crane operations, engineering and construction groups, subcontractors, geotechnical consultancies and research organisations. To find out more, Contact Us.

The advantages of the ZFG 3000 Light Weight Deflectometer include:

• Direct deflection readings: accelerometer directly connected to the base plate
• Time saving in testing (a maximum of 3 minutes per measuring point)
• Accurate repeatable results
• One-man use: designed for field testing
• Easy to use: Push start and pull the drop weight to the top
• No additional loading vehicle or support is required
• Readings captured on SD-card for data memory (10,000 data sets) allowing immediate on-site results printing and data transfer to PC
• Data interpretation software allows data storage, analysis and manipulation and easy inclusion into reports
• GPS-System for immediate determination of test position integrated with Google Maps
• Using extensions to the ZFG 3000, dynamic CBR (California Bearing Ratio) can be measured in-situ in the field and also laboratory CBR in a cylinder can be simulated.

Traditionally the load-carrying capacity of soils is determined by strength tests, such as California Bearing Ratio (CBR) and the static plate bearing test (DIN 18134; similar to BS1377; ASTM D1195, D1196).

An improvement on these tests is the dynamic load plate test known as the Light Weight Deflectometer (LWD).

The Light Weight Deflectometer (ZFG 3000) is a mobile device to determine the bearing capacity and the compaction quality of soils and unbound base courses in a quick and easy way. The ZFG 3000 LWD is designed for this application and has been approved by ASTM E2835-11 Standard Test Method for Measuring Deflections using a Portable Impulse Plate Load Test Device, ASTM E2583 – 07(2011) Standard Test Method for Measuring Deflections with a Light Weight Deflectometer (LWD) and the German Road and Transport Research Association under TPBF-STB Part B8.3_97.