A knitted spacer fabric has a tightly knitted bottom layer, a more loosely knitted upper layer and linking fibres extending across the space between the lower and upper faces. Settable material, e.g. cement, is introduced into the space between the upper and lower faces and can be caused to set by the addition of a liquid, e.g. water. Until set, the fabric is flexible and can be shaped but after the material in space has set, the fabric is rigid and can be used as a structural element in a wide range of situations. The bottom layer has an extension that extends beyond the upper face and is connected to the upper face by elastic connecting fibres that draw the extension towards the other face, thereby at least partly closing the space at the edge of the cloth and preventing the settable material from spilling out. In addition, the packing of the settable material and maximum space between the faces are such that only a predetermined amount of liquid can be accommodated within the space and that amount is matched to the water required to set the cement.

A knitted spacer fabric has a tightly knitted bottom layer, a more loosely knitted upper layer and linking fibres extending across the space between the lower and upper faces. Settable material, e.g. cement, is introduced into the space between the upper and lower faces and can be caused to set by the addition of a liquid, e.g. water. Until set, the fabric is flexible and can be shaped but after the material in space has set, the fabric is rigid and can be used as a structural element in a wide range of situations. The bottom layer has an extension that extends beyond the upper face and is connected to the upper face by elastic connecting fibres that draw the extension towards the other face, thereby at least partly closing the space at the edge of the cloth and preventing the settable material from spilling out. In addition, the packing of the settable material and maximum space between the faces are such that only a predetermined amount of liquid can be accommodated within the space and that amount is matched to the water required to set the cement.

A hardener composition can be used for a reactive resin system containing a reactive resin based on radically curable, ethylenically unsaturated compounds. The hardener composition contains a hardener for the reactive resin and a filler mixture. The filler mixture is composed of a first filler having a first average particle size d.sub.50,1 and a second filler having a second average particle size d.sub.50,2. The first average particle size d.sub.50,1 of the first filler is greater than the second average particle size d.sub.50,2 of the second filler (d.sub.50,1>d.sub.50,2). The ratio d.sub.50,1 to d.sub.50,2 (d.sub.50,1:d.sub.50,2) is in the range of 8:1 to 100:1. The filler mixture is useful, and a reaction resin system can contain the hardener composition.

A hardener composition can be used for a reactive resin system containing a reactive resin based on radically curable, ethylenically unsaturated compounds. The hardener composition contains a hardener for the reactive resin and a filler mixture. The filler mixture is composed of a first filler having a first average particle size d.sub.50,1 and a second filler having a second average particle size d.sub.50,2. The first average particle size d.sub.50,1 of the first filler is greater than the second average particle size d.sub.50,2 of the second filler (d.sub.50,1>d.sub.50,2). The ratio d.sub.50,1 to d.sub.50,2 (d.sub.50,1:d.sub.50,2) is in the range of 8:1 to 100:1. The filler mixture is useful, and a reaction resin system can contain the hardener composition.

A non-polar reaction resin mixture can be used to improve the adhesion of a mortar composition based on radically polymerizable compounds, in particular based on urethane (meth)acrylates, on the surface of semi-cleaned and/or damp boreholes in mineral substrates. The use of a non-polar reaction resin mixture in the corresponding mortar composition reduced the sensitivity thereof to dampness and inadequate cleaning conditions, so that mortar compositions are obtained overall which are characterized by improved robustness against external influences.

A non-polar reaction resin mixture can be used to improve the adhesion of a mortar composition based on radically polymerizable compounds, in particular based on urethane (meth)acrylates, on the surface of semi-cleaned and/or damp boreholes in mineral substrates. The use of a non-polar reaction resin mixture in the corresponding mortar composition reduced the sensitivity thereof to dampness and inadequate cleaning conditions, so that mortar compositions are obtained overall which are characterized by improved robustness against external influences.

A method of controlled hydration expansion of a smectite-containing day mineral (SCM) within an aqueous environment in a confined volumetric space, the method comprising the steps of: —introducing an amount of an SCM into said volumetric space via an inlet thereinto, and initiating the hydration expansion of the SCM to release SCM particles into the confined volumetric space, and increase the pressure therein; and —introducing a flow path modification to control said released SCM particles from undergoing a recompression, said modification thereby maintaining the pressure in the volumetric space.

A method of controlled hydration expansion of a smectite-containing day mineral (SCM) within an aqueous environment in a confined volumetric space, the method comprising the steps of: —introducing an amount of an SCM into said volumetric space via an inlet thereinto, and initiating the hydration expansion of the SCM to release SCM particles into the confined volumetric space, and increase the pressure therein; and —introducing a flow path modification to control said released SCM particles from undergoing a recompression, said modification thereby maintaining the pressure in the volumetric space.

Disclosed is a novel cement and aggregate compositions, to uses thereof for protecting surfaces, in particular surfaces likely to be affected by biocorrosion.

Disclosed is a novel cement and aggregate compositions, to uses thereof for protecting surfaces, in particular surfaces likely to be affected by biocorrosion.