GFRC From Scratch Mix Design

Below is a very basic mix design for Glass Fiber reinforced ConcreteGFRC applications. There are many different variations of GFRC but this recipe has proven to work very well for us at Fishstone. Both batches below produce approximately 1/3 cu. ft. 

Mist or Face Coat - we like to call this the beauty coat

Portland (Type 1)

18.5 lbs


4.5 lbs

Silica Sand (#40-50 sieve)

23 lbs


6-6.5 lbs

KongKrete™ Liquid Acrylic Polymer


PVA Fibers 8mm (optional)

85 grams

Optimum 380 superplasticizer

23-42 mL

C-64 Defoaming & Densifying admixture

5-10 mL

Backer Coat

The Recipe for the backer coat or Premix (self-consolidating) are the same as the face coat with a few exceptions.

1) You do not need PVA fibers (although they will not hurt) and substitute with a larger amount of AR Glass fibers.

2) Adjust the fluidity by adjusting the amount of Optimum and water