Ordinary concrete as a cladding material, is exposed to many chemical and / or physical effects that may cause wear in its structure during its service life. These effects stem from the natural characteristics, and / or the environment in which the concrete is used, and / or the reactions between alkalis and reactive aggregates in the concrete. Therefore, ordinary concrete may not be sufficient for interior and exterior cladding, and a more durable material alternative such as GRC can be used instead.
Glassfibre reinforced concrete or GRC (also known as GFRC), is an engineered material that contains cement, aggregates, and alkali resistant (AR) glass fibers that are ingrained in the cementious matrix and it is one of the most advanced materials currently used in the facade construction industry.
The differences between GRC panels and the ordinary concrete panels are related to the components and their manufacturing technology. The additive in GRC and AR glass fiber in the structure make the main difference between them. These differences make GRC advantageous for facade cladding compared to ordinary concrete. There are many reasons to use GRC instead of ordinary concrete in facade cladding systems.
Betonex CBOARD GRC facade panels are composite materials having the shrinkage value between 0.5-1.5 mm/m and low permeability. Its water/binder ratio varies between 0.2-0.4, whereas in conventional concrete it is around 0.6-0.7. Thanks to its special structure, the porosity of Betonex CBOARD is lower and its chemical resistance is higher than ordinary concrete.
Precast GRC facade panels contain no steel reinforcement and therefore does not have the same durability concerns, corrosion or rust will not occur, and there is no cover requirements as in steel reinforced concrete. Alkali resistant glass fibres used in GRC contain >16,5% ZiO2 and a coating on the glass to maximise long term performance. With its fibrous structure, the flexural strength of Betonex CBOARD facade cladding panels are very high. In case of the composite failure, the load is transferred to the fibers resulting in a ductile failure.
Precast GRC panels can be much thinner than traditional concrete panels, making them a lot lighter for a panel with same area from traditional concrete. This makes the panels easier to handle and reduces the load on the facade, therefore, the overall load on the foundation. GRC facade cladding can replace non-structural precast concrete where weight and/or shape may be problematic. Less weight of GRC also means reduced site-work and transport costs including lifting activities on site, reducing the costs on these activity items. In addition, CBOARD Panel and CBOARD Decorative products are enviromentally friendly composites since natural ingredients are used during the manufacturing.