Concrete structures and construction methods

Abstract

Aspects of the invention relate to concrete structures having concrete columns. Cables can provides support as a flat beam in the horizontal slab above so that the columns can be used and largely spanned apart. The columns can be substantially aligned in a row or at least one column can be offset from the row of columns. Further, the concrete structure can include large cantilevered surfaces, such as balconies or walkways. Aspects of the invention further relate to a system for forming concrete columns using tunnel forms. In addition, embodiments of the invention can be used to form an offset column in a secondary pour. Aspects of the invention are particularly well suited for creating multi-level buildings of at least five stories.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This Application claims the benefit of U.S. Provisional Application No. 60 / 498,751, filed on Aug. 31, 2003.FIELD OF THE INVENTION [0002] The invention relates in general to concrete construction and, more particularly, to concrete structures and construction methods using tunnel forms. BACKGROUND OF THE INVENTION [0003] The use of tunnel forms in construction is known. Generally, tunnel forms are metal structures that can be used to form vertical walls and horizontal slabs simultaneously. The use of tunnels forms in construction provides advantages of speed, reduced construction costs and simplicity. Tunnel forms have proved to be successful, economical and efficient in the construction of buildings that did not require large open spaces such as simple hotels, apartment buildings, and some condominiums. [0004] However, the range of applications in which tunnel forms can be economically and efficiently used is limited because vertical wa...

AI Technical Summary

Benefits of technology

"The present invention provides a construction system and method using tunnel forms that can be economically and efficiently applied to a variety of building types. This allows for the creation of large open spaces, such as balconies and walkways, while minimizing the use of transfer slabs. The invention also allows for the use of post-tensioned cables as a flat beam supported by concrete columns, which further expands the range of applications for tunnel forms. The invention provides a method for forming a concrete column that is offset from a row of columns, as well as a method for forming a second slab. Overall, the invention provides a more efficient and flexible way to use tunnel forms in construction."

Problems solved by technology

However, the range of applications in which tunnel forms can be economically and efficiently used is limited because vertical walls must be provided in intervals up to 16 to 18 feet on center to provide support for the horizontal slabs.

Such relatively frequent placement of vertical walls can limit the architectural freedom of the building.

Further, tunnel form construction could not be economically applied to the construction of large cantilever surfaces, such as those extending from about 8 feet to about 9 feet.

Thus, the use of tunnel forms to construct luxury or premium type buildings was limited.

Again, such constructions are not economical, efficient and simple under current tunnel form construction methods and designs.

While appropriate for low rise buildings, such a construction is not ideal for taller structures, such as those with five or more stories.

Moreover, such a construction can have a number of drawbacks that can diminish the advantages of tunnel form construction.

From a construction standpoint, steel is more difficult to use in forming columns as compared to other materials, such as concrete.

Further, the process of forming a steel column within a tunnel form is relatively complicated.

For instance, additional labor intensive processes may be required, such as welding two vertically aligned steel columns together.

Moreover, the formation of steel columns in tunnel forms is expensive and can significantly increase the cost of a project in comparison to using concrete.

Delays can be introduced and the costs can grow significantly when such a construction system is applied to high rise buildings.

In addition, the are a number of limitations in the use of steel columns.

Steel columns are limited in strength capacity if a builder wishes to keep the columns the same thickness as the walls of the building or within a reasonable size.

Steel columns are susceptible to corrosion, which can limit the potential areas of use.

However, a building with steel columns should not be constructed and is not practical near a beach for fear of salt spray corrosion, which can jeopardize the structural integrity of the columns and the building, unless expensive maintenance is applied over the life of the buidling.

Further, in the context of a parking garage in a building, use of steel columns is not a standard practice.

There are also fire protection issues attendant in steel that are not associated with other materials, such as concrete.

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