Biodegradable or degradable film bag for the placement of concrete or formation of concrete repairs in and around watercourses

Abstract

The invention relates to a bag used for the placement of concrete or grout, either hand placed or pump filled, in and around watercourses. The bags are impermeable and contained in nature, made of biodegradable, degradable or water soluble polymer film, typically made from renewable starch based polymers or water soluble polymers. The bags offer a means of easily and simply placing concrete or grout, safely, cleanly and without risk of contamination to the watercourse or environment from cement leakage, being impermeable in nature, whilst allowing the polymer film to safely degrade, dissolve or disintegrate, in the environment, without the risk of unsightly or environmentally detrimental polythene waste being placed in the watercourse.

Description

CROSS-REFERENCE TO APPLICATIONS[0001]This Application claims the benefit of foreign priority under 35 USC §119 of GB Patent Application 0819163.7, filed Oct. 20, 2008, the entire content of which is hereby incorporated by reference.TECHNICAL FIELD[0002]The present invention relates bags and, in particular, to a bag used for the placement of concrete or grout, either hand placed or pump filled, in and around watercourses.BACKGROUND AND SUMMARY[0003]There are many instances in which concrete needs to be placed in or around watercourses, for example, in order to repair or protect bridges from undermining or scour.[0004]Simple, hand-placed, concrete filled hessian bags, similar to sand bags, have traditionally served this function, to enable the placement concrete in rivers for example, however, the open weave of the fabric allows the escape of cement fines into the water which can result in pollution. As a consequence, strict environmental legislation has resulted in their disfavour wi...

AI Technical Summary

Benefits of technology

[0008]Biodegradable polymer film can also degrade rapidly, with the use of micro-organisms, with both biodegradable or degradable forms breaking down over a period of typically weeks to months, into carbon dioxide, water and methane. The ultimate result is that the polymer film and bagwork degrades and disappears, in a safe and non-polluting manner.

[0009]For the function of placing concrete in water, the use of biodegradable, degradable or watersoluble polymer film to form the bags has several advantages. Firstly, the impermeable nature of the polymer film means that unlike hessian, no cement fines can escape the bag, preventing cement pollution from escaping into the environment. The polymer film successfully achieves the primary role of containing the concrete and forming a concrete block, without allowing cement fines to escape out of the bag. Secondly, the use of polymer film means that seams can be glued or heat welded, eliminating the need for sewing for the bulk, if not all, of the bag that would typically be required for fabrics. Bags could therefore be mass-produced, using machines, significantly cheaper than sewn bags.

[0010]Finally, having a

Problems solved by technology

Simple, hand-placed, concrete filled hessian bags, similar to sand bags, have traditionally served this function, to enable the placement concrete in rivers for example, however, the open weave of the fabric allows the escape of cement fines into the water which can result in pollution.

As a consequence, strict environmental legislation has resulted in their disfavour with environmental consulting bodies.

As a result, this contained impermeable form of bagwork tends to be considerably more costly to manufacture than traditional hessian bags.

The potential for rips or tears and subsequent spillage of wet or dry material is however significant.

Firstly, the impermeable nature of the polymer film means that unlike hessian, no cement fines can escape the bag, preventing cement pollution from escaping into the environment.

Non-biodegradable polymer film, typically traditional oil based polythene, could conceivably be used for the bags, to place the concrete in an impermeable manner, however, the polythene would be unsightly and have a negative and very long term impact on any environment.

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