Guidance On Use Of Light Weight Falling Deflectometers (LWDs) – June 2021

May 28, 2022 | Bearing Capacity, Compaction Control, Rail Formation & Ballast Condition Assessment

National Asset Centre of Excellence (NACOE), a collaboration of Queensland Department of Transport and Main Roads and the Australian Road Research Board (ARRB), has released their final report for the Best practice in compaction quality assurance for pavement and subgrade materials – P60 project.

Importantly, in Appendix A of this report, is the Draft Technical Note – Guidance on Use of Light Weight Falling Deflectometers (LWDs) to be Accepted as an Alternative Method for Verification of Earthworks Compaction Requirements – June 2021.

This draft technical note provides guidance on implementation of Light Weight Deflectometers including a flow chart showing key steps for assessment/derivation of equivalent acceptance thresholds for LWD use (in lieu of traditional (density) testing minimum thresholds included in MRTS04 – General Earthworks).

We believe this “How to” guide will be very useful for industry on projects across the country. You can visit our website to access the full report and other resources. 

We’d really value feedback and thoughts on the Draft Technical Note.

I would hate to go back to doing the Plate Load Test using the old method using dial gauges. It would be so time consuming, not to mention manually recording and then processing all the results.

Daniel Pearce

Director - Pearce Geotech

The ZFG 3000 is an excellent tool and should be included in any professional contractors equipment list of assets. This tool should have a similar impact on the construction industry as the laser level. The ability to accurately and reliably measure this aspect of ground condition will improve the quality of the work and remove doubt as to the progress of the project.

I bought my ZFG 3000 and on the same day less than two hours later, it had paid for itself. Using this instrument, I was able to demonstrate scientifically, repeatably and independently the quality of the work that we had completed for our client. Ending the disagreement and creating an improved working relationship. Most jobs are not as confrontational as this was however, most jobs are built to a standard. The contractor can now measure as required, to know on site, at the time of testing if this standard is being achieved.

I strongly recommend the ZFG 3000 Deflectometer to any earthmoving, civil construction contractor. Good luck with your projects.

Jim Bassett

Managing Director, Bassearth Pty Ltd

Since hiring the LWD I have used it on numerous jobs in a wide variety of material types all over WA. The ability to give “real time” test results have worked particularly well for me as i can show my clients numerical values which gives them a direct understanding of some of the benefits using Betta Roads has brought to their road construction projects. The feedback I have been receiving over the last few months has lead me to purchase the LWD and incorporate its use as an integral part of our projects.

Paul Bright

Director at Betta Roads Pty Ltd Perth Area, Australia



Insitutek Blogs

We find clients are often looking for ways to improve geotechnical testing outcomes and do it more efficiently at the same time. This drives their buying decision making. Australian Soil and Concrete Testing (ASCT) was a case in point when they were searching for Plate Load Test equipment for their upcoming Collector Wind Farm project. Some of the things that motivated them include: […]

We are excited to introduce the addition of a new Liquefaction Risk Estimation module in WebSprint©. Paired with our cutting-edge products, PANDA® and GRIZZLY®, this module enables you to assess the liquefaction risk of soils exposed to seismic stress. PANDA® Instrumented DCP: This cutting-edge tool provides dynamic penetrometer soundings, delivering precise data crucial for seismic risk evaluations. GRIZZLY® […]

The Australian Geomechanics Society is gearing up for a series of geotechnical events across VIC, WA, NSW, and SA-NT. We are thrilled to inform you that we will be sponsoring and attending these exciting geotechnical events, and we would love for you to join us. It’s a fantastic opportunity to catch up, explore our booth (VIC), and stay informed about […]