A recent upgrade of a bus corridor near the Grand Canal Dock required precise subgrade evaluation before the asphalt could be laid. The contractor faced Dublin’s notoriously variable glacial till, where bearing capacity can shift within metres. Our laboratory performed a soaked CBR test on remoulded samples compacted at the expected site density, simulating the worst-case moisture scenario that Dublin’s damp climate presents year-round. The data fed directly into the pavement thickness design, avoiding over-engineering the capping layer while safeguarding against rutting. For projects where the in-situ material varies, we often pair the laboratory CBR with a field CBR assessment to correlate lab values with actual ground response.
A soaked CBR value below 2% demands either soil stabilisation or a complete capping replacement — there is no middle ground in pavement design.
