CASE STUDY – Concrete Manholes in Brisbane

Case Study – Concrete Manholes in Brisbane

Substrate

1 x Concrete Manhole used in Trunk Line Sewer, Size = 1050 dia x 2.7m deep + biscuit

Condition

 The manhole was in need of repair due to severe high levels of H2S attack and erosion.

Preparation

The chamber was vented above and below the chamber on the sewer line and then an air mover was used to increase the ventilation and airflow. A high pressure power wash was followed by acid etch, wash down and then dried using the air mover.
Spray ApplicationSpraying took 1.5 hours including the preparation. 1 coat of Epoxy was applied at 6mm using approx 40 gallons of Epoxy resin

Outcome

 Redlands Shire Council were impressed with the outcome, more work followed.
Concrete-Manhole-1

Before; – with the temporary pipe to protect the epoxy spray from live sewer.

 

Concrete-Manhole-1

Condition before spraying

 

Concrete-Manhole-1

Preparation finished and spraying commences

Concrete-Manhole-1

Complete Spray

CASE STUDY – Concrete Catch Pits

Case Study – London Underground

Substrate Details

2 Concrete Catch Pits approx size 1200x600x1500mm.
The pits are located Approx 100m from the platform station, they are positioned on either side of the track. One is on the north bound side and the second on the south bound

LUL induction certificate was required by all engineers before any work could be carried out including pre inspection. The work could only be carried out between the hours of 1am and 5am and pending any other engineering works. 

Preparation

Suck out all the water and waste in the sump using gully sucker followed by power wash.
Cracks and holes were repaired using a high build epoxy resin mastic which was applied by hand using a trowel
The concrete surface was then washed using a diluted (max 10%) Sodium Hypochlorite (bleach)
This is applied using a hand held sprayer with Viton seals. Used to remove and kill off any algae or bacterial growth.
Power wash again.  Gully suck water from the wash down.  A diluted Hydrochloride Acid wash (max 10%) using hand held sprayer with Viton seals. This was required to etch the concrete surface to give maximum adhesion and also to remove any surface salts on the concrete structure.
Power wash again.

 Spraying

Epoxy spray applied  with one coat at 6mm.  Once the resin cured the acro props were reinstalled. 

concrete-catch-pits-before

Before

 

concrete-catch-pits-after

After

CASE STUDY: Brewery Waste Sump

Case Study – Brewery Waste Sump

Substrate2 sumps
MaterialPrecast Concrete caisson bolted together and sealed with Rubber Gaskets.  The Rubber Gaskets had failed causing infiltration due to poor installation.
Purpose of the sumps Treatment of brewery waste products, including hops, yeast and barley
Significant preparation was required prior to spraying which took 5 days.
Sump 1 Approx size 4m dia x 4m deep
ConditionThe sumps was in reasonable condition with minimal infiltration. The surface had a previous coating which proved extremely difficult to remove.
PreparationHigh pressure power wash. The existing coating was then abraded to provide a suitable key for the epoxy followed by power wash again.
The entire surface was then acid etched and washed down with water prior to spraying.
Spraying1 coat at 6mm thick.
 Sump 2Approx size 7m dia x 5m deep
Condition The sump had extreme infiltration and the surface had a previous coating which proved extremely difficult to remove.
PreparationHigh pressure power wash. The existing coating was then abraded to provide a suitable key for the epoxy followed by power wash again.
Areas of infiltration were then drilled and an injection grout system applied to seal the leakages which included fast setting cement (waterplug).
The entire surface was then acid etched and washed down with water prior to spraying.
Spraying1 coat at 6mm thick.

 

Brewery-waste-sump-before

Before

 

Brewery-waste-sump-after

After

 

CASE STUDY: Brick Manhole Chambers

Case Study – Brick Manhole Chambers

Substrate10 x Brick Manhole Chambers
SizeManholes all approx 600mm x 600mm at various depths, ranging from .75m to 2m deep
PurposeDrainage system on chemical plant
ConditionVarious, ranging from a very severe build up of mineral deposits to oil and grease residue and had previously been coated with an unknown material plus minor structural defects.
Repair detailsChemicals were leaking into the water table causing pollution issues with EA. A sealed system was required because the drains had recently been re-lined because a sealed system was required
PreparationWhere required the manhole was isolated using inflatable drain plugs and then high pressure power washed. Previous coating was removed using a scabbler. Mineral build up was removed using a CP9 and scabbler. The oil/grease residue was removed using acetone.
Spray1 coat at 6mm applied
Time Scaleapprox 7 days

 

Brick-Manhole-Chambers-Before

Before

 

Brick-Manhole-Chambers-After

After