|
 |
 |
 |
| |
CLIENT CASE 1
BARRHEAD SPRAYED CONCRETE REPAIR
When Network Rail’s bridge inspection programme alerted
them to a severely bulged area of spandrel wall on Overbridge
No 44, Barrhead near Glasgow, CK contracts were invited to site
with a view to effecting remedial works.
The
structure, a masonry arch constructed in sandstone, had developed
a bulge in the lower South Eastern spandrel wall adjacent to the
arch barrel, severe enough that a section of the outer masonry
leaf had become completely detached and had fallen to the embankment
below.
Following meetings with main contractor, First Engineering Ltd,
a reinforced sprayed concrete repair was specified as best suited
for the remedial works. Thereafter, a designed tube and fitting
access scaffolding was constructed from cess level during a weekend
track possession to provide a working platform at the repair area.
The scaffolding was erected outwith the railway kinematic envelope
and encapsulated in ‘monarflex’ sheeting to contain
rebound resulting from the sprayed concrete operation. A proprietary
steel access stairway was also installed to link the working platform
to the roadway above from which the works could be safely accessed
midweek without the need for any rail interface.
On completion of the temporary works, CK Contracts removed all
surrounding loose masonry and installed temporary props to the
bulged area which would remain in place until the sprayed concrete
was ready to be applied. The repair area was then manually cleaned
using hand tools and steel lacing bars were installed within the
repair, anchored into the rear leaf of masonry. Following installation
of the reinforcement bars, the road passing over the structure
was closed to accept the concrete spraying equipment.
Working from the encapsulated scaffolding platform, a 30N/mm²
designed concrete mix was sprayed into the void area and built
up to a thickness 5mm proud of the surrounding masonry. A sprayed
concrete flash coat was also extended onto the adjacent voussoir
area and arch soffit to stabilise some open jointed brickwork
in those areas.
Following the successful completion of the sprayed concrete works,
all temporary works were removed during a subsequent weekend track
possession 8 days from the commencement of the works within programme
and to budget.
------------------------------------------------------------------------------------
CLIENT CASES...
|
|
 |
 |
 |
|
|
