Glassfibre Reinforced Concrete or GRC (sometimes called Glassfibre Reinforced Cement and Glass Fiber Reinforced Concrete or GFRC), is a composite comprising cement, fine aggregate, water, chemical admixtures and alkali resistant glass fibres. The glass fibres reinforce the concrete, much as steel reinforcing does in conventional concrete. The glass fibre reinforcement results in a product with much higher flexural and tensile strengths than normal concrete, allowing its use in thin-wall casting applications. 

GFRC is a lightweight, durable material that can be cast into nearly unlimited shapes, colours and textures. It is rapidly gaining prominence in the construction industry worldwide for the economic, environmental, technological and aesthetic benefits it brings. Its low consumption of energy and natural raw materials makes it one of the most environmentally friendly choices available, and it can be tailored to meet a wide variety of specific performance, appearance, and cost parameters. 

GRC was first introduced in 1969 and has today matured into a material with a wide range of matrix modifiers such as acrylic polymers, rapid set cement, and additives to improve its long-term stability. Extensive independent test and performance data are available on all aspects of matrix formulation.

There are two basic processes used to fabricate GFRC – the Spray-Up process and the Premix process. The Premix process is further broken down into various production techniques such as spray premix, cast premix, pultrusion and hand lay-up.

Variants of GRC
The Alkali Resistant glassfibre is generally used at the 2-5% level in the manufacture of factory finished prefabricated products either by the spray process or using traditional concrete casting methods.

It is also used in the 1-2% range for reinforced renders as a site applied mix and can also be used to control plastic shrinkage cracking, microcracking and bleeding of site-cast concrete.