DETAILS of the structural problems that have led to Bradford Interchange bus station being closed until at least September have been revealed.

Falling concrete in a basement car park led to the bus station section of the Interchange being closed in January.

Since then, several surveys have been carried out, and the station’s owner, West Yorkshire Combined Authority, is due to make a decision on whether the station should be repaired or replaced in September.

It has now made the findings of the surveys - carried out shortly after the closure - public.

What were the findings of the surveys?

• The car park structure was found to be in generally fair condition, with a combination of defects of varying severity.

• Defects pertaining to quality of construction were apparent in a number of locations, with spalling due to insufficient provision of cover to steel reinforcement. The majority of these defects are minor and do not warrant repair.

• There are two notable areas of defective concrete; one beneath the western concourse entrance, where falling concrete was recorded prior to the procurement of the inspection, and the other within the fire escape to the south-west fire escape, adjacent to the Santander building. Both these defects should be addressed in the near future.

• The beams and columns of the car park were generally in good condition with some visible hairline cracks.

• Construction joints throughout the slab were in generally good condition, with a small number of areas where voids were apparent, presenting the potential for passage of water.

• Defects relating to the management of water through drainage and waterproofing to the slab were prevalent throughout the structure.

• Defects to drainage have resulted in widespread water leakage, and subsequent corrosion to ancillary steelwork

• Efflorescence on the underside of the slab and on the beams were likely caused by water ingress through the slab, due to localised failure of waterproofing. Long-term ingress of water to the reinforced concrete, particularly where de-icing salts are used around the Interchange, increases the risk of corrosion to steel reinforcement and subsequent spalling.

• Around openings in the concrete slab for the stairwells between the concourse level and car park, water leakage is apparent around the openings, indicating a lack of upstand and associated waterproofing to prevent it.

• Despite the prevalence of water leakage there is limited evidence of corrosion products to areas of reinforced concrete.

The survey suggests a range of remedial works including work to “address defective concrete” and resin injection to stop further water ingress, as well as further surveys – which are currently being carried out - to assess the long-term future of the station.