Extensive concrete repairs needed for major Bristol motorway bridge built in the 1970s
A motorway bridge in Bristol is in poor condition and needs extensive concrete repairs according to safety inspectors. The Eastville Viaduct, which carries traffic over Junction 2 of the M32, was built half a century ago but now suffers from “significant defects”.
The 1.1-kilometre bridge was built in two phases in 1970 and 1975, and is used by tens of thousands of drivers every day. But recent safety inspections, released under freedom of information laws, reveal that some of the concrete is cracking and bearings are corroding.
Underneath the bridge, several large areas of spalling can be seen. This is where concrete has broken away, exposing reinforcing steel to the elements and leaving it vulnerable to corrosion. Historic problems with construction and maintenance have also compounded issues.
National Highways said the bridge is “structurally sound and safe”, but it is planning a major programme of repairs. These will include repairing concrete and installing new barriers, waterproofing and drainage — although the works, which are likely to disrupt drivers for months, are not expected to begin for several years.
Inspectors working for National Highways, the government company responsible for motorways and major A roads, carried out a general inspection report in June this year. The 521-page report listed many defects of the Eastville Viaduct and recommended repairs.
The report said: “Evidence of sawdust and off-cuts of reinforcement nails and screws clearly demonstrates a lack of any quality control when preparing the formwork for concrete pours. Corrosion is present to the bearing top plate and bearing bolts. As the bearings were only inspected from ground level, it couldn’t be confirmed whether any section loss has occurred.
“Both the middle and south drainage system catchment trays and associated carrier pipes for the comb and tooth joints are blocked, with extensive water staining and corrosion present. A member of the public also confirmed that during periods of wet weather, significant leakage occurs from the drainage trough.
“The mounting brackets are corroded and must be replaced. This defect is clearly causing damage to the element or structure. It is known that where gullies have been found to be broken or blocked the maintenance teams were instructed to fill them, as this was deemed to be quicker and more cost-effective than repairing the gully lids.
“Some bearings have incorrectly fitted securing or holding-down bolts which may be interfering with their operation. Clearly poorly installed and a failure to maintain or rectify under maintenance thereafter.”
Drainage systems are blocked and corroded, leading to water leaking throughout the structure and onto the pavement below. Water high in chloride, from road salts, has been able to seep into the structure. Some areas of spalling measure three metres wide, with exposed corroding reinforcement steel visible from below the bridge in several places.
About £22.6 million worth of repairs are needed to the bridge, according to the report. These include spending £10 million on repairing the concrete deck; £16,500 on removing blockages from the drainage system; £10 million on waterproofing; and £2 million on replacing or refurbishing corroded bearings. However, the works are not anticipated to start until the year 2026.
Speaking to the Local Democracy Reporting Service, Sean Walsh, route manager for National Highways, said: “The M32 Eastville viaduct will need significant renewal in the coming years, and we have begun making plans for these works now. These works will ensure the long-term viability of the viaduct, the safety of its users, and also improve the area for local residents.
“This will include concrete repairs to the bridge itself, new barriers that will also incorporate noise mitigation, new gantries, drainage, lighting, and new waterproofing, as well as a new contiguous deck to allow traffic to be moved around during construction.
“While the viaduct remains structurally sound, we have been working in conjunction with consultants to develop the plans, with traffic modelling under way to ensure the works cause the minimum disruption possible.
“We understand this work will cause some inconvenience and disruption, but we are making every effort to ensure the impact on those who use the road is kept to a minimum and hope to keep it open in some capacity throughout the works. We will also work with the West of England Combined Authority, Bristol City Council and South Gloucestershire Council to ensure there are appropriate mitigations in place, where possible.”
Residents living near the Eastville Viaduct have been calling for new noise barriers for several years, and National Highways announced eight years ago that the M32 from the viaduct to the M4 was a “priority area for noise reduction”. But this work has been delayed due to the need for extensive repairs, leaving residents suffering from constant traffic noise.