When making glass fibre-reinforced concrete, you need glass fibres with special properties that are not available at your local DIY shop. Above all, the glass must be alkali-resistant, i.e. resistant to strong alkalis, because normal fibres are attacked by concrete and decompose over time.
Our rolls of AR glass fibre strand mat are alkali-resistant (AR) and, therefore, right for processing with concrete. It is used in the laminating technique, either during lamination into a negative form, or when positive laminating any forms, such as shown in the youtube video "WERKANLEITUNG BETONKUGEL" from Sven Backstein. The individual fibres are held together as a mat by a water-soluble adhesive. You do not need to cut the material; it can be very easily torn into pieces of appropriate size. Upon contact with water, the adhesive dissolves and the fibres can then be stirred into the mortar or cling as a whole mat to curved surfaces. It is even beneficial at times to first break down the glass fibre mats into single fibres in water and then add them while preparing with the mortar.
In our online shop you buy glass fibres only from renowned manufacturers, in small quantities at a reasonable price. Order full rolls even more economically.