Fibre reinforced cement

Claim 2

A FIBRE-REINFORCED POZZOLANIC CEMENT PRODUCT IN WHICH THE CEMENT MATRIX CONTAINS AT LEAST 10% BY WEIGHT OF A POZZOLANA AND FROM 0.5 TO 10% BY WEIGHT OF FIBRES WHICH ARE ALKALIRESISTANT GLASS FIBERS COMPRISING A SILICA/ZIRCONIA GLASS CONTAIN ING AT LEAST 6.0 MOL PERCENT OF ZIRCONIA.

Claim 3

A cement product according to claim 1, in which the pozzolana content of the matrix is at least 15%.

Claim 4

A cement product according to claim 1, in which the pozzolana content of the matrix is at least 25%.

Claim 5

A cement product according to claim 1, in which the pozzolana content of the matrix is from 35 to 45%.

Claim 6

A cement product according to claim 1, in which the pozzolana content of the matrix is at least 40%.

Claim 7

A cement product according to claim 1, in which the pozzolana is a natural pozzolana.

Claim 8

A cement product according to claim 1, in which the pozzolana is pulverised fuel ash.

Claim 9

A cement product according to claim 1, in which the pozzolana is a soda/lime/silica glass.

Claim 10

A cement product according to claim 1, in which the glass is one based on the system SiO2/ZrO2/Na2O.

Claim 11

A cement product according to claim 1, in which the glass contains at least 65% SiO2 and at least 10% ZrO2 by weight.

Claim 12

A fibre-reinforced cement product according to claim 1 of improved water durability, said product having modulus of rupture and impact strength retentions of at least 80% when tested before and after immersion in water at 50*C. for 28 days.

Claim 13

A cement product according to claim 1 having a modulus of rupture of at least 3,500 pounds per square inch, an impact strength of at least 50 inch pounds per square inch, and which retains at least 80 percent of said properties when immersed in water at 50*C. for 28 days.

Claim 14

A fibre-reinforced Portland cement product containing from 35 to 45% by weight of pulverised fuel ash and reinforced with from 0.5 to 10% by weight of fibres which are fibres of an alkali resistant silica/zirconia glass containing at least 9 mol percent of ZrO2 and having a modulus of rupture after initial curing which increases with time.

Claim 15

A fibre-reinforced Portland cement product containing from 35 to 45% by weight of pulverised fuel ash and reinforced with from 0.5 to 10% by weight of fibres which are fibres of an alkali resistant silica/zirconia glass containing at least 9 mol percent of ZrO2 and having a modulus of rupture after initial curing which increases with time.

Claim 16

A process of producing a fibre-reinforced cement product in which from 0.5 to 10% by weight of alkali resistant glass fibres comprising a silica/zirconia glass containing at least 6.0 mol percent of zirconia are incorporated in a cement matrix comprising Portland cement containing at least 10% by weight of a pozzolana.

Claim 17

A process of producing a fibre-reinforced cement product in which from 0.5 to 10% by weight of alkali resistant glass fibres comprising a silica/zirconia glass containing at least 6.0 mol percent of zirconia are incorporated in a cement matrix comprising Portland cement containing at least 10% by weight of a pozzolana.

Claim 18

A process of producing a fibre-reinforced cement product in which from 0.5 to 10% by weight of alkali resistant glass fibres comprising a silica/zirconia glass containing at least 6.0 mol percent of zirconia are incorporated in a cement matrix comprising Portland cement containing at least 10% by weight of a pozzolana and in which the resulting composite is subjected to a curing treatment at elevated temperature.

Claim 19

A process of producing a fibre-reinforced cement product in which from 0.5 to 10% by weight of alkali resistant glass fibres comprising a silica/zirconia glass containing at least 6.0 mol percent of zirconia are incorporated in a cement matrix comprising Portland cement containing at least 10% by weight of a pozzolana and in which the resulting composite is subjected to a curing treatment at elevated temperature.

Claim 20

A process according to claim 15, in which the curing treatment is conducted in water at a temperature of at least 60*C.

Claim 21

A process according to claim 16, in which the curing treatment is conducted at 60* - 80*C for at least 2 days.