a.b.e.® duragrout CG – Curling Remediation of Surface Beds / Hardstands

• Core drilling machine (32 mm diameter drills)
• Grout mixer (mechanical or paddle mixer)
• 20 L mixing buckets
• Low-pressure hand grout pump
• Measuring containers
• Cleaning equipment (water supply)
• PPE (gloves, goggles, respirators)

4.1 Assessment

• Identify all areas affected by curling
• Confirm extent of voids and slab displacement
• Mark repair zones
• Mark out the cores in 4.5m x 4.5m panels as per below drawing. (Core to be 32 mm dia. by the thickness of the concrete)

4.2 Environmental Conditions

• Minimum temperature: 5°C and rising
• Ideal range: 20°C – 30°C
• Avoid excessive wind and heat during curing

4.3 Surface Condition

• Concrete must be structurally sound
• Free from loose debris at drilling points

• Divide affected area into 4.5 m × 4.5 m panels
• Mark drilling positions:
  • Core positioned centrally in each panel
  • Maintain ~300 mm from joint/saw cut

6.1 Core Drilling

• Drill 32 mm diameter holes through slab thickness
• Ensure full penetration to void beneath slab
• Drill all required cores before grouting

Purpose:
Allows trapped air to escape and ensures grout penetration

6.2 Surface Preparation

• Remove dust and debris from drilled holes
• Ensure holes are clean and unobstructed

Prevent contamination that may affect grout bonding
Method: During the drilling of the holes, a vacuum must be used to extract the drilling dust, and not allow the dust to drop into the hole / void.
Purpose: Dust could potentially block the path of the grout being injected / poured into the holes
Method: A small amount of water could be poured into the holes at least 2 hours prior to commencing with the grouting process and allowed to saturate into the sub-base.
Purpose: This will prevent moisture loss from the fluid grout during the plastic set phase to retain volumetric stability, while also reducing surface tension as the grout flows across the sub-base.

6.3 Mixing of duragrout CG

Mixing ratio (per 25 kg bag): Total water = 8.75 litres
Procedure:

1. Add ±7 litres water into mixer
2. Slowly add grout while mixing
3. Mix for 2–3 minutes
4. Add remaining water and mix an additional minute
5. Ensure lump-free, homogeneous consistency

6.4 Grouting Process

• Pour grout into pump hopper through sieve
• Inject grout using low-pressure hand grout pump
• Pump grout through core hole into void

Key requirements:

• Pump from one point per void to avoid air entrapment
• Maintain continuous flow
• Allow air to bleed through adjacent cores

6.5 Filling and Monitoring

• Continue pumping until:
  • Void is filled
  • Refusal or back pressure is reached
• Observe settlement:
  • If grout drops due to voids, refill

6.6 Core Hole Finishing

• Fill core holes to surface level using duragrout CG. If the grout settles and drops below the surface bed level due to air pockets, the core hole must be patched with the same grout as used under the surface bed/hardstand.
• Finish flush with slab surface

• Protect exposed grout from rapid drying if required.

8.1 Pre-Application

Confirm:

• Correct drilling pattern
• Equipment functionality
• Environmental compliance

8.2 During Application

Monitor:

• Grout consistency
• Pump pressure
• Grout take volumes

8.3 Post-Application

Verify:

• Full void filling (no hollow sounding areas)
• No visible settlement
• Surface integrity

• Wear PPE at all times
• Avoid inhalation of cement dust
• Prevent skin/eye contact with grout
• Ensure adequate ventilation
• Follow product MSDS guidelines

• Clean tools immediately with water
• Remove hardened material mechanically

• Store in dry, sealed conditions
• Shelf life: 12 months in original packaging
• Avoid moisture exposure

• Do not re-temper grout once stiffened
• Discard material exceeding working time
• Ensure continuous mixing and pumping
• Carry out site trials where required

Maintain records of:

• Repair locations
• Material batch numbers
• Volumes used
• Environmental conditions
• Completion dates