The motorway was due to be closed until 6am today (4 May) but the road was fully reopened 28 hours early following Balfour Beatty Vinci Joint Venture’s 24-hour operation.
The beams are for new Recreation Ground Bridge, a pedestrian and cycle bridge linking Datchet to Upton Court Park in Slough.
The work is part of the joint venture's US$1.06 billion project to upgrade the M4 between junctions 3 and 12 to a smart motorway.
The old bridge was the first on the project to be demolished in September last year and the new bridge will be open to the public later this year.
