Production of GRC composites

Various methods have been developed for the production of GRC components. These methods have mostly been adapted from the glass fibre reinforced plastics industry, with proper modifications to adjust for the special nature of the cementitious matrix. To obtain a product of an adequate quality the mix composition should be carefully controlled, to be compatible with the production process, while at the same time providing the needed physical and mechanical properties in the hardened composite. Thus, the properties of GRC composites vary over a wide range, and are a function of a complex combination of the production process and the mix composition. A detailed discussion of the design and production of GRC components is beyond the scope of this chapter. These topics are covered in various publications and guidelines [31-37] and only some essential points will be discussed in Section 8.7 and Chapter 14. 

1 It should contain a relatively large volume of fibres ( 5% by volume) since this is the primary reinforcement in the thin component. 

2 The matrix is a cement-sand mixture (i.e. mortar), with a relatively small sand content (1 0.5-1 1 cement/sand ratio), to enable both the production of a thin component and the incorporation of a large fibre content. 

Five different production processes have been developed for making GRC components premixing, spray-up, extrusion, winding and lay-up of mats. Some of 

Method of manufacture Spray-suction Hand-moulded premix Extruded premix Pressed premix 

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Figure 8.11 Schematic description of production of GRC composite by winding (after True [31]).

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