Structural Repair F


Cemix® Structural Repair F is a flowable structural performance concrete for concrete repairs & concreting which are poured or pumped into place. It is useful when a flowable product is required, reinforcing is congested and/or repair volumes are too large for hand placed mortars. It is used for remedial work on concrete where high performance & durability are required.

Typical Application / Uses:

Cemix® Structural Repair F may be used for:

  • Flowable concrete repairs & performance concreting to all concrete structures
  • Congested steel reinforcing repairs & concreting
  • Smooth off form finishes
  • Columns
  • Beams
  • Bridges
  • Marine structures
  • Water retaining structures
  • Precast connections and between precast elements
  • Structural void filling


  • Flowable
  • 5mm maximum aggregate size
  • One component
  • Shrinkage compensated
  • Short curing times
  • High bond strength
  • Durable
  • Waterproof
  • Impermeable to water borne aggressors such as chloride ions
  • Improved abrasion resistance


Durability enhancer, steel protection & waterproofing:

Cemix® Structural Repair F contains an integral crystalline concrete durability enhancer & waterproofing material, which further protects & waterproofs the mortar in-depth by making it completely impermeable to water borne aggressors such as chloride ions. This admixture permanently protects the mortar & imbedded structural steel from long-term corrosion & deterioration.

Substrate Preparation:

Concrete substrates should be sound & roughened to ensure a good bond. They should be uncoated & clean, free from all contaminants, loose particles, dirt, oil, mould, curing compounds, sealers & paints etc. For a durable repair cut a square or rectangular perimeter edge around the repair at least 25mm in depth. Remove all oxidation from exposed rebar & ensure that there is at least 25mm (or ‘finger room’) behind each rebar. For deep critical repairs use anchors and steel mesh as required to enhance bonding. The better the substrate preparation & condition the better the end result. The concrete substrate should ideally be at least 3 months old

Formwork Preparation:

The area to be repaired must be enclosed with good quality rigid watertight formwork. The formwork must be able to rigidly confine the Cemix® Structural Repair F until it has set. Treat the formwork with a Cemix® form release agent. Formwork should be flushed out just prior to application.

Header box & Air vents:

When not pumping the material & where appropriate, use a suitable header box delivery system to pour the product into place. Create a head of pressure to force the product into place. Avoid air entrapment by use of filling pipes or pump which fill from the bottom up. Use suitable air vents to vent air as the product flows into place.

Movement / Control Joints:

Honour any control joints in the concrete substrate – do not apply product over control joints.


Mix whole bags of product. Add 2.5L of water to mixer & then add product gradually to water. Add rest of water slowly whilst mixing until the desired consistency is achieved. Maximum total water is approximately 3.0L per 20kg bag. Mix thoroughly for 4 minutes using a drill & paddle or mechanical mortar mixer. Do not mix more product than can be mixed, placed & finished in 40 minutes. In hot weather consider using chilled mixing water. In very cold weather consider using warm mixing water. For deep & large volume pours, use chilled mixing water to counteract the heat of hydration and prevent thermal cracking.


Saturate the concrete substrate with water just prior to concrete application. Avoid water ponding. Pour or pump the Cemix® Structural Repair F into place while the substrate is still damp. Where appropriate, use a suitable header box & pipe delivery system, or a suitable grout pump. Application is from the bottom of the repair up, completely filling the void & avoiding air entrapment. Compact the concrete once it is in place. For a durable repair apply product to a minimum depth of 25mm. Trowel finish as required.


It is very important to prevent early plastic state moisture loss prior to the product setting. Cure product thoroughly after it has set by keeping it wet & covered for at least 7 days. Avoid product freezing for at least 3 days.

Technical Data:

Appearance – Sand/Cement grey powder.

Strength (MPa) - 40MPa @ 7 days; 60MPa @ 28 days

Application Temp- 5ºC - 30ºC

Yield / Coverage - Approximately 10.5L or 0.0105m3 per 20kg bag.

Please enter the following where applicable:

Working Time – 40 minutes at 20ºC

Bond Strength – > 3MPa

Thermal Coeff. Of Exp – 9.0 x 10-6 mm/mm/ ºC

Chloride Ion Permeability – < 1000 coulombs

The data shown above reflects typical results based on laboratory testing under controlled conditions. Reasonable variations may occur on site.


Substrate Temperature - +5°C min. / +30°C max.

Ambient Temperature - +5°C min. / +30°C max.


Clean all tools with water & brush immediately after use.


Can be stored in its original packaging in a dry place well sealed for a period of six (6) months after production. Do not store opened bags.


For deep & large volume pours, use chilled mixing water to counteract the heat of hydration and prevent thermal cracking.

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