Swcc Jeddah Plants J2, J3, J4 Rehabilitation Of Concrete Structures
The scope of work includes remedial of deteriorated structures consisting of plant J2 (Jeddah Two plant) constructed in 1978, plant J3 plant constructed in 1980, and plant J4 constructed in 1982. Structures rehabilitated are:
Plant J2 – Turbine Hall Roof – removal of the damaged waterproofing membrane along with some damaged precast concrete slabs supported on a steel structure which is to be replaced by newly casted ones. Removal of temporary utilities, ladders, part of the parapet, etc. The slab soffit inside the turbine hall was coated after reinstatement of the waterproofing membrane system at the roof.
Plant J3 – Pump Canisters : cylindrical structures, built underground. Due to the congested location of these pumps, and to enable the demolition operation to proceed, sheet piling was installed to stabilize the surrounding soil adjacent to the structures. Demolition of the structure was 4.25 m below ground level. A de-watering system was installed. After demolishing and recasting the sheet piles were left in place permanently. The total number of the canisters were eight, and work on these items was related to a shutdown schedule.
Plant J2 and J3 – Cable Trenches : Excavation around the trenches to the foundation levels, demolition of the deteriorated concrete, cast-in new concrete, painted-protected the surfaces and backfilled around the cables. Covers were replaced with a lightweight material and sealed.
Plant J4 – Chlorination Building – Local repairs consisting of reskinning of walls and columns and casting new concrete to the affected areas. The roof slab were reinforced with structural steel members properly supported and structurally connected to the concrete structure. New concrete plinths were constructed to support the existing equipment. All newly constructed items were coated in accordance with the specifications.
Plant J4 – Turbine Hall, Ground Floor Slab : The part above the cable trenches were completely demolished and a new slab cast in place. The other part, above soil, has voids under the slab and a grout was injected to fill these voids. New tiles were laid with sand cement mortar. Frames and steel embedments were cleaned and coated and replaced.