Slip formed concrete structure

Abstract

The invention provides a concrete structure of which at least a part has been formed by slip forming with panels inside the slip form, the panels facing the slip form.

Description

FIELD OF THE INVENTION[0001]The present invention relates to concrete structures. More specifically, the invention relates to slip formed concrete structures, particularly structures made of high strength concrete.BACKGROUND OF THE INVENTION AND PRIOR ART[0002]Currently, many concrete structures, such as concrete shafts, are typically formed by slip forming, alternatively termed slip casting. Compared to forming with fixed forms, slip forming is very favorable, particularly from an economical point of view, since the extent of the work is greatly reduced. However, the surface of a slip formed concrete structure includes irregularities, particularly when high strength, abrasion resistant concrete qualities are used. The result is reduced erosion and abrasion resistance, reduced service life and reduced surface quality, compared to a structure having a smooth surface, all of which has technical and economical consequences. Repair of irregularities or eroded or abraded surface is often...

AI Technical Summary

Benefits of technology

The present invention provides a new way of producing slip-formed concrete structures that have smooth surfaces without any irregularities like small cracks, crazes, or voids. This is difficult to achieve when using high-strength, abrasion-resistant air-rich concrete qualities. By eliminating or reducing irregularities in the surface, the invention improves the durability and longevity of the structure. This can be beneficial for any concrete structure, particularly for high-strength quality concrete structures exposed for erosion, abrasion, or wear, as reduced drag or friction can be beneficial, and subsequent treatment can be facilitated. Deterioration, wear, ageing, and ingress of salts and chemicals take place from the surface inwards, so the invention provides better resistance to such factors. Testing so far has confirmed the beneficial effect of the method, but more testing is needed to quantify its effects in all aspects.

Problems solved by technology

However, the surface of a slip formed concrete structure includes irregularities, particularly when high strength, abrasion resistant concrete qualities are used.

The result is reduced erosion and abrasion resistance, reduced service life and reduced surface quality, compared to a structure having a smooth surface, all of which has technical and economical consequences.

Repair of irregularities or eroded or abraded surface is often very expensive and the quality is still reduced.

Forming with fixed forms for all or a part of a concrete structure is often very expensive.

Structures used in the sea in areas infested by drifting surface ice have so far not been protected in the zone abraded by ice by a slip formed concrete abrasion allowance, but with a protective steel structure, due to the above mentioned technical problems.

For concrete structures such steel protection is very expensive, requiring extensive scaffolding and additional work at high elevation, and may not be a good technical solution since the integrity has been questionable.

Protection using concrete has so far not been possible for the desired reliable, long-lasting, affordable and simple solutions sought for by the industry.

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