MACt GFRC Premix Cement - Light Grey (20KG)

MACt Premix GFRC Light Grey (20kg)


When creating a cast-in-place benchtop, additional 500grams of 12mm HD ANTI-CRAK fibres are required per bag of premix. 



MACt Premix GFRC Light Grey (20kg) is economical, Class A shrinkage compensated glass fibre reinforced concrete for architectural, construction casting and general duty. MACt Premix is manufactured by MACt at their Queensland Manufacturing Facility. MACt Premix has been designed to be used in any application where Ultra-High-Performance Concrete is needed.



MACt Premix GFRC Light Grey (20kg) is used for custom manufacturing GFRC furniture, cladding, three-dimensional art, street furniture and benchtops, where normal concrete won’t meet the performance requirements. The formulation is supplied ready mixed requiring only the simple addition of accurately measured potable water, Alkali Resistant Fibre, and desired colour to produce a super-strong, dense and flexible concrete.


Features and Benefits

MACt Premix is a cost-effective, time-saving general GFRC concrete with the following benefits:

  • Enhanced early strength with high ultimate strength and low permeability ensure the durability of the hardened premix
  • The gaseous expansion system compensates for shrinkage and settlement in the plastic state
  • Can be dry-packed, rammed, trowelled, poured and pumped or sprayed.
  • Pre-packaged material overcomes potential on-site mixing variations
  • Develops high early strength without the use of chlorides
  • No metallic iron content to cause staining
  • Twin component hydraulic binder glass fibre modified system with additional hydration, flow, defoaming, plasticising and anti-shrink admixtures.



MACt Premix GFRC Light Grey (20kg) is a general-purpose Ultra-High-Performance Concrete mix and is supplied ready to use in 20 kg bags. The flow or consistency of the GFRC mix is controlled by the addition of potable water and MACt Plasticiser.


  • Add all the required water (see below) to a clean bucket, add half of the powder and mix for three minutes with a drill and paddle. Add the second half of the powder with mixing and continue to mix for a further 3 mins until the grout is smooth.
  • Adding the maximum recommended of 3.0 litres per bag produces a flowing shrinkage compensated GFRC for gap thicknesses from 10 mm up to 100 mm. This also is a low viscosity mix for use as a pumped GFRC concrete.
  • Adding 2.9 litres produces a sprayable consistency which resists sagging on vertical surfaces.
  • Adding 2.8 Litres gives a trowel able stiff grout with a consistency sufficient for building up in unsupported structures against vertical and overhanging mouldings
  • Adding less than 2.6 litres may result in a flash-set grout.
  • The storage, handling and placement of the MACt Premix must be in strict accordance with the manufacturer’s instructions. A positive volumetric expansion of 1-3% shall occur while the MACt Premix is in a plastic state.
  • In hot weather for extra work time replace up to 50% water with ice (by weight) or use MACt Hydration Stabiliser (retarder)

MACt Premix GFRC Light Grey (20kg) MODIFICATIONS

Modification of MACt Premix by the addition of accurately weighed pigments may be undertaken. The addition of significant levels of pigment will reduce strength and flow characteristics. To increase flow add 3Ltr of water per bag, and use an additional MACt Plasticiser to achieve the required consistency. Non approved additives shall not be used and can seriously impact the performance of this product.



If MACt Premix GFRC Light Grey (20kg) is kept in its original packaging in a dry environment, a shelf life of 12 months is to be expected.

This time may be reduced if the product is subject to high temperatures or humidity.

Bulk bags are expected to remain covered in plastic until use.



MACt Premix GFRC Light Grey (20kg) is packaged in 20kg bags. Other packaging options can be requested.



  • CMB: 0.015 m3
  • 20mm: 0.50m2 
  • 30mm: 0.44 m2
  • 50mm: 0.24 m2

MACt GFRC Premix Cement - Light Grey (20KG)

SKU: 9E4D6
  • Contains cement and silica, avoid inhalation of dust. Wear gloves, safety goggles, and OSHA approved dust respirator during mixing and placement. Refer to product M.S.D.S. (Material Safety Data Sheet) for additional safety information. Do not take internally. Avoid prolonged contact with skin.