Lightweight Deflectometer (LWD) Testing

LWD testing can obtain CBR values on your subgrade, formation and sub base material and because it's small, lightweight and requires no reaction load or dead-weight it is perfect for:
  • CBR values on a site where you have no plant to act as a reaction load
  • CBR values where the test area is inaccessible to a 4 x 4 vehicle for Insitu CBR by the traditional plunger method 
 
We carry out LWD testing all over the UK and can arrange it at very short notice.

Sometimes called Dynamic Plate Tests, they are quick to perform and another great benefit to you is that through the use of Bluetooth the test measurements are instantly transferred to our technician's tablet to provide you CBR values on the spot.  This means you can take immediate remedial action should any result fail your criteria.

The test works by measuring the stiffness of the material being tested and then converting this value to an approximate CBR value.  Stiffness is the measure of a materials ability to return to its original shape after loading;, what we call the elastic stage.  This means the test is best suited to made ground, recycled materials and aggregates because they have elastic stage properties whereas clays tend to have very little elastic stage properties to measure.

  • Highways England compliant apparatus

  • Surface & Stiffness Modulus measurements for road design

  • Sub base compliance LWD Testing specified in IAN 73/06 Revision 1 (2009) Design Guidance For Road Pavement Foundations (Draft HD25)

Pile Mat and Crane Hardstanding LWD testing

Traditionally pile mat and crane hardstanding top surfaces are subject to measurement of bearing capacity (strength) using the plate load test.  To gain a better understanding of the platform's performance and reduce the risk of under-performance going undetected LWD stiffness measurements can be undertaken in addition to the plate load tests to provide benefits such as:

 

  • Soft spots can be immediately identified without having to do and pay for lots of plate bearing tests and waiting for tests results

  • The entire surface of the platform can be checked as the LWD is very quick to do compared to plate bearing testing

  • Platform edges can be checked in detail as they represent the most common area of failure

  • Large areas can be tested quickly and efficiently without having to pay for several site visits for traditional plate bearing tests