The TRL Dynamic Cone Penetrometer (DCP) test is a quick and effective method of estimating the strength and thickness of unbound pavement layers.
TRL can undertake DCP testing in soft verges, in soft central reservation, at the base of cores or at the bottom of trial pits to the requirements of Design Manual for Roads and Bridges CS 229 Data for pavement assessment.
The in situ test measures the penetration rate for each drop or blow of the hammer weight. The resulting depth profile is particularly good for identifying anomalously weak layers.
The TRL DCP was designed over several years in the 1980s based on our work in the UK and overseas. The equation for the relationship between mm/blow and Californian Bearing Ratio (CBR) for use in the UK was developed by TRL and is referenced in CS 229.