Fast, efficient concrete road replacement on a busy motorway

The Challenge

Connecting the M5 South of Birmingham and the M6 to its East, the M42 is one of the Midlands’ busiest stretches of motorway. It was also the first in the UK to be converted to a managed motorway. 18 months before resurfacing work was due to take place, we met with the Highways Agency and potential contractors to discuss the approach that would be the most cost effective and least disruptive to road users.

Our Solution

Traffic levels were such that closing lanes and working during the day would result in unacceptable delays. Not to mention exposing maintenance crews to danger from passing traffic. For the motorway to be closed and resurfaced at night, however, it would take an extremely rapid setting product to meet the return to service deadline of 6am each morning.

The perfect job for Pozament PQX – an ultra fast hardening cement that sets to 20N/mm² in four hours and 25N/mm² in 5 hours.

Results and Benefits

With possession based on traffic flow, contractors Costain typically moved in at 8.30pm each evening to break up the existing surface. By midnight, road crews were ready to pour a 300mm layer of PQX Cement based concrete, knowing it would be ready to take the weight of rush hour traffic just six hours later. As Pozament Technical Manager Iain Spence explains: “Traditional liquid-based accelerators produce concrete at S1 consistency, but PQ-X offers more flexible working, at S2 while giving the same level of strength gain. And because it’s factory blended and quality controlled, each kilo of PQ-X performs exactly as expected.”