US 5,857,293 A · Flexible formwork assembly

Abstract

A method of casting concrete structures using a "flexible formwork assembly". The assembly has flexible sheets suspended from a fixed location, preferably from a supporting frame assembled on top of the reinforcing members, with rigid stress distribution members located to the outer surface of flexible sheets in predetermined spacings so as to carry load directly and to redistribute stress in the sheet so as to aid the sheet to withstand the concrete pressure. The majority of stress distribution members are arranged in pairs which are directly connected to each other by ties in wall type structures. Reinforcing members are used as a main frame or skeleton to hold and suspend the formwork assembly. Spacers are used to aid in maintaining the sheets in a desired location which ensure adequate concrete cover to the reinforcing prior to pouring of the concrete. Stress distribution members provide external shape, configuration and pattern to the concrete surface by their shape and arrangement. In-situ concreting of walls of most shapes and configurations under water is made viable by this system.

Claims26

Dependent claims

A formwork comprising:

a flexible substantially water impermeable sheet to define at least one side of a space to receive unset concrete,
stress distribution members located on a major surface of the sheet at spaced locations between edges of the sheet, said major surface in use not confronting said space, said stress distribution members being rigid relative to the sheet to thereby firstly carry the pressure of concrete applied to the stress distribution members area and secondly carry the sheet forces generated by concrete pressure applied to the surrounding sheet, and thirdly by their size redistributing and limiting the sheet distresses, arising from the concrete within the space pressing on the sheet, to thereby aid the sheet to withstand pressure applied to the sheet;
and
a plurality of ties, each tie being fixed to and extending from an associated one of the stress distribution members, the ties extending through the sheet and being fixed so as to support the associated stress distribution members in a desired position to thereby support the sheet in a desired configuration until the concrete sets.

1 more element

A method of erecting formwork to at least partly enclose a space to receive unset concrete, said method comprising the steps of:

providing a flexible sheet;
locating on a major surface of the sheet, a plurality of stress distribution members prior to or after suspending the sheet from a fixed location, said stress distribution members being rigid relative to the sheet to thereby firstly carry the pressure of concrete applied to the stress distribution members and secondly carry the sheet forces generated by concrete pressure applied to the surrounding sheet, and thirdly by their size redistributing and limiting the sheet distresses to thereby aid the sheet to withstand pressure applied to the sheet, the stress distribution members being positioned at spaced locations between edge portions of the sheet;
providing a plurality of ties;
suspending the sheet from a fixed location;
securing each tie to an associated stress distribution member and fixing the ties so that the stress distribution members are held in a desired position to thereby hold the sheets in a desired configuration defining at least one side of said space, with the tie members extending from their associated stress distribution members and through the sheet and into said space.

2 more elements

Dependencies are inferred from the claim text.

Flexible formwork assembly

Life of this patent

Flexible formwork assembly

Life of this patent

Abstract

Claims26