Flexible composite
AssigneeConcrete Canvas Technology Ltd.
InventorsPeter Brewin, Christopher Evans, Marcin Kujawski, William Peake
Life of this patent
Estimating the term…
Abstract
An expandable porous framework, the framework containing a dry cementitious powder fill that when exposed to an aqueous media, will expand against the constraint of the framework and set to form a solid, hard and coherent material, the formwork being porous to liquids but substantially impermeable to the powder fill.
Claims49
An expandable porous formwork, said formwork containing a dry cementitious powder fill that, when exposed to an aqueous media, will expand against the constraint of the formwork and set to form a solid, hard and coherent material, the formwork being porous to liquids but substantially impermeable to the powder fill.
A formwork as claimed in any preceding claim, in which the formwork is arranged to exert a confinement pressure on the powder fill such that, as it expands, it exerts an increasing confinement pressure on the cementitious powder with an increasing degree of expansion.
A formwork as claimed in any preceding claim, in which the formwork and the expanded and set powder fill form a seal, once set.
A formwork as claimed in any preceding claim, in which the formwork is toroidal in shape, including with a rectangular or square cross section (with radiused corners).
A formwork as claimed in claim 7 or claim 8, in which the formwork is made by one of the following processes:
- weft knitting:
- circular warp knitting, also known as knit braiding:
- braiding:
- weaving:
- folding and sealing or seaming a flat fabric such that there is a straight seam along one edge or both edges;
- folding and sealing or seaming a flat fabric in a spiral wrap shape;
- an extruded tube;
- a 3D printed tube;
- by extruding, injection moulding, vacuum forming or rotationally moulding a polymer tube or toroid form, with holes in it that has optionally been stiffened by forming thicker elements in the toroidal direction or inserting stiffer composite elements in the toroidal direction.
A formwork as claimed in any preceding claim, in which the formwork and dry cementitious powder are assembled on to a pipe.
A formwork as claimed in any preceding claim, which further includes electrically resistive elements.
A formwork as claimed in any preceding claim, in which the formwork may be temporarily sealed by a wax or polymer coating.
A formwork as claimed in any preceding claim, in which the formwork is tubular in shape and consists of an inner and outer surface connected by elastically or plastically deformable linking elements, the outer surface being elastically or plastically deformable and being permeable to aqueous media but being substantially impermeable to the powder fill.
A cementitious powder blend (CSP Blend) for use in the formwork of any preceding claim, which powder swells and sets on exposure to an aqueous medium and which has the following composition:
- a. a calcium silicate based cementitious powder;
- b. an alumina-based cement containing or mixed with a calcium oxide component;
- c. a calcium sulfate;
- d. a superabsorbent polymer (SAP);
- e. a metal oxide that is thermally stable above 120° C.
- f. a dense phase, insoluble sulfate compound;
- and
- g.a retardant material which can be used to retard the initial setting of the cement, including component (a) and/or component (b).
A cementitious powder as claimed in any one of claims 20 to 25, in which component (f) is present in an amount of 0-30% by mass of the total cementitious powder, or in an amount of 2-15% by mass of the total cementitious powder, or in an amount of 5-10% by mass of the total cementitious powder.
A device for sealing the space between a pipe and another pipe or between the pipe and a bare hole, in which the device uses a porous formwork as claimed in any preceding claim.
Dependencies are inferred from the claim text.