Abstract: A mixer for mixing glass fibres into a thick aqueous cement slurry comprises means for feeding glass fibres on to the surface of a batch of the slurry in an upright cylindrical chamber, an agitator mounted on a coaxial vertical shaft and carrying at its lower end both a plurality of short impeller blades and a long horizontal member with tip blades of opposite sense to the impeller blades, so as to cause vertical as well as horizontal circulation of the slurry, and stationary baffles on the wall of the chamber angled to cause production of standing waves on the surface of the slurry.

Abstract: A mixer for mixing glass fibres into a relatively dilute aqueous cement slurry, e.g. for use in forming glass fibre reinforced cement products on an asbestos-cement making machine of the Hatschek or Bell type, comprises an annular chamber with a tangential slurry inlet, a helical rising floor, a coaxial conical outlet disposed to receive slurry flowing over the inner wall, which is lower than the outer wall, and a fibre inlet above the conical outlet so that the fibres are mixed with the slurry as it passes down the wall of the conical outlet in a vortex motion.

Abstract: A method is provided for making a cement composite product such as a flat or profiled sheet, or a pipe, containing glass fibre as reinforcement instead of the traditional asbestos, wherein a cement and water slurry of flowable consistency is made with high shear agitation, the glass fibre is mixed with the slurry in a static mixing apparatus (i.e. having no moving parts) by bringing together flows of the slurry and of the glass fibre and then altering the path of the conjoined flow, and the glass fibre-containing mixture is immediately subjected to the conventional deposition on a water-permeable web, formation of a profile if desired, drainage of the water from the slurry through the web, and curing the deposited cement to form the product.