Discussion on Papers 11 and 12

DR R. MANIFOLD, Pilkington Reinforcements Ltd, UK Mr Le Moigne and Mr Rangeley have both referred to the lining of canals as a means of improving irrigation systems. In Mr Rangeley's Paper the significance of lining the long lengths of tertiary canals in irrigation schemes is discussed.

Several Indian states are looking at glassfibre-reinforced cement (GRC) watercourses and structures under a UNDP/FAO project which examines new lining materials.

GRC - basically a cement mortar reinforced with CemFIL alkali-resistant glass fibres - has been available for a long time now, mainly as a lightweight facade or architectural component, as in civil engineering applications, such as permanent formwork. It combines the compressive properties of the matrix with the tensile and bend properties of the glass fibre to give a strong, impact-resistant, lightweight material used typically in sections 6-25 mm thick.