18 Apr Concrete repairs to the transom beams at the tug jetty, Durban harbour
BACKGROUND TO PROJECT
Various transom beams were mechanically damaged on a jetty in Durban harbour. Smart Civils was approached to propose a remedial solution to repair the beams. The allowed time to complete the works was a big restraint on the project and it was suggested to use a rapid curing cementitious product, applied with a dry gunite application method.
SCOPE OF WORk
Concrete repairs to transom beams on existing tug jetty – Durban harbour:
- Cut and breaking damaged areas
- Sandblast exposed rebar with 350bar HP washer
- Apply corrosion protection
- Repair the patch using dry spray application of Sikacrete Gunite 502
CHALLENGES / RESTRAINTS ON PROJECT
Concrete repairs to transom beams on existing tug jetty – Durban harbour:
- Confined space to work in
- Ocean tides reducing the time of access to the soffit
- The Sikacrete gunite 502 sets very quickly so we were limited to a wood float finish
SUMMARY OF EXECUTION OF WORKS
Access into the working area was via boat/pontoon. All tools, equipment and people were transported at a predetermined time prior to the low tide. Working platforms were assembled with modular floating pontoons out of the water, then lowered into the water and towed into place. These HDPE platforms provided enough stability to carry out all operations to the underside of the beams. Electrical cables, water and gunite piping were fed into the work area via cored holes through the slab of the jetty. Production hours were dictated by the tides, thus working hours had to be scheduled around this. Specialised tasks such as application of gunite were scheduled for days when the tides were very low, this allowed additional time under the jetty.
Ventilation fans were used to keep the air flowing under the jetty. Oxygen levels were monitored every 15 minutes in the work area to ensure the safety of the team underneath.
PROJECT DETAILS
Contract
Contract Value
Start Date
End Date
Contract Duration
Client
Consulting Engineers
Sub-Contractor
R 1.9 M
10 January 2023
6 April 2023
10 Weeks
WBHO
Transnet In House