GB2325944A

GB2325944A - Reinforced cementitious columns or wall sections

Info

Publication number: GB2325944A
Application number: GB9711636A
Authority: GB
Inventors: Colin Banks
Original assignee: R O ROURKE AND SON Ltd
Current assignee: R O ROURKE AND SON Ltd
Priority date: 1997-06-05
Filing date: 1997-06-05
Publication date: 1998-12-09
Also published as: GB9711636D0

Abstract

A cementitious column (36) or wall section is made by firstly precasting a (preferably metal-reinforced) cementitious shell (14), standing the precast shell (14) on a base (10) so that starter bars (12) embedded in the base (10) are upstanding within the shell (14), placing continuity bars (28) in the shell (14) to project above the top (30), pouring fresh cementitious material into the shell (14) and allowing the fresh cementitious material to harden.

Description

Reinforced Cementitious Columns or Wall Sections Field of the invention This invention relates to a method of construction of a solid, reinforced, load-bearing vertical column or a. solid, reinforced, load-bearing vertical wall section of cementitious material such, for example, as concrete.

Summat of the invention As seen from one aspect of the invention, there is provided a method of construction comprising the following steps: (a) precasting a tubular shell of cementitious material; (b) standing the reinforced tubular shell of cementitious material vertically on a floor in such a position on the floor that starter reinforcing bars which are upstanding from the floor are located within the interior of a lowermost part of said tubular shell of cementitious material; and (c) pouring fresh cementitious material into the reinforced tubular shell of cementitious material and allowing the fresh cementitious material to harden, to produce either a solid, reinforced, load-bearing vertical column or a. solid, reinforced, loadbearing vertical wall section of cementitious material.

The shell may be precast with metal reinforcing bars extending longitudinally and circumferentially within the thickness of the wall of the shell.

The shell may be of circular cross-section or of non-circular cross-section, for example, square or rectangular cross-section.

Preferably the floor is of cementitious material.

Preferably the inside surface of the reinforced tubular shell of cementitious material is made rough so that it keys with the fresh cementitious material when the latter has hardened.

Preferably an inflatable and deflatable former is used during formation of the inside of the reinforced tubular shell of cementitious material, the inflatable and deflatable former being inflated while the inside of the shell is being formed and deflated during a step of extracting the former from the inside of the shell.

Further features and advantages of the invention will become apparent from the following description of examples and embodiments of the invention, given by way of example only, with reference to the accompanying drawings.

Brief Description of the drawings FIG. 1 is a diagrammatic illustration of a first stage of a preferred method of construction in accordance with the invention; FIG. 2 is a diagrammatic illustration of a second stage of the preferred method of construction in accordance with the invention; FIG. 3 is a diagrammatic illustration of a third stage of the preferred method of construction in accordance with the invention; FIG. 4 is a diagrammatic illustration of a fourth stage of the preferred method of construction in accordance with the invention; FIG. 5 is a diagrammatic illustration of a fifth stage of the preferred method of construction in accordance with the invention; FIG. 6 is a diagrammatic illustration of a sixth stage of the preferred method of construction in accordance with the invention; FIG. 7 is a cross-section on plane Vil-Vil of FIG. 2; and FIG. 8 is a longitudinal section on plane VIII-VIII of FIG. 7.

Detailed description of the preferred method ofconstruction in accordance with the invention Referring to the drawings, and more particularly FIG. 1, the first stage of the preferred method of construction in accordance with the invention involves the formation of a base, or floor, 10 of cementitious material, for example, concrete, with L-shaped starter bars 12 embedded in and upstanding from the floor 10. Straight starter bars may be used in place of L-shaped starter bars if desired.

Referring to FIGS. 7 and 8, the first stage also involves the precasting of a tubular shell 14 of cementitious material, for example, concrete, preferably with metal reinforcing bars 16, 18 extending longitudinally and circumferentially, respectively, within the thickness of the wall 20 of the shell 14, although the reinforcement bars 16 and/or 18 may be omitted if desired.. The reinforcement bars 16, 18 are not shown in any of FIGS. 2 to 6. The inside surface of the reinforced tubular shell 14 is made rough so that it will key with the fresh cementitious material (see below) when the latter has hardened. This may, or may not, require a special roughening step. An inflatable and deflatable former (not shown) is used in well-known manner during formation of the inside of the reinforced tubular shell 14, the inflatable and deflatable former being inflated while the inside of the shell 14 is being formed and deflated during a step of extracting the former from the inside of the shell 14 Referring to FIG. 2, the second stage involves standing the reinforced tubular shell 14 vertically on the floor 10, in such a position on the floor 10 that the starter reinforcing bars 12, which are upstanding from the floor 10, are located within the interior 22 of a lowermost part 24 of the shell 14. Temporary props 26 are provided as required, to restrain the shell 14 from falling or toppling over.

Referring to FIG. 3, the third stage involves arranging vertical "continuity" metal reinforcement bars 28, inside the shell 14, so that they project above the top 30 of the shell 14.

Referring to FIG. 4, the fourth stage involves pouring fresh cementitious material 32, for example, fresh concrete, into the interior of the shell 14, so that the fresh cementitious material 32 fills the interior of the shell 14 up to the top 30 of the shell 14, whereby the starter reinforcement bars 12 and the continuity bars 28 become embedded in the cementitious material 32, which is allowed to harden off. The combination of the shell 14, reinforcement bars 12, 28 and hardened-off cementitious material 32 forms a solid reinforced column 36.

Referring to FIG. 5, the fifth stage involves the casting of a suspended floor 34 of metalreinforced cementitious material, such as concrete, to rest upon the top 30 of the column 36 formed by the combination of the shell 14, reinforcement bars 12, 28 and cementitious material 32. The metal reinforcement of the floor 34 is not shown. As shown in FIG. 5, the reinforcement bars 28 in the column 36 are sufficiently long to project above the top of the floor 34 in the same way that the reinforcement bars 12 project above the floor 10.

Referring to FIG. 6, the sixth stage corresponds to the second stage shown in FIG. 2, in that a second shell 38 (similar to shell 14) is stood upon the floor 34 in such a position that the reinforcement bars 28 are located within the interior of a lowermost part of the shell 38, in the same way that the starter bars 12 are located within the interior of the lowermost part 24 of the shell 14.

Subsequent seventh, eighth and ninth stages correspond, mutatis mutandis, to the third, fourth and fifth stages illustrated in FIGS. 3 to 5.

Further floors may be added in a similar manner if desired. Finally, a flat roof of cementitious material may be placed on top of the top most column in the same way as the floors below.

Of course, the illustrated columns, one on top of another, are repeated at intervals throughout the structure, as is usual for a structure with floors supported on columns.

In a modification, not shown, the cylindrical shells may be replaced by shells of square or rectangular cross-section to form wall-sections. The constructional stages are the same, apart from the change in shapes, and it is believed that description and illustration of them would be superfluous.

Claims

CLAIMS:

1. A method of construction comprising the following steps: (a) precasting a tubular shell of cementitious material; (b) standing the reinforced tubular shell of cementitious material vertically on a floor in such a position on the floor that starter reinforcing bars which are upstanding from the floor are located within the interior of a lowermost part of said tubular shell of cementitious material; and (c) pouring fresh cementitious material into the reinforced tubular shell of cementitious material and allowing the fresh cementitious material to harden, to produce either a solid, reinforced, load-bearing vertical column or a. solid, reinforced, loadbearing vertical wall section of cementitious material.

2. A method as claimed in claim 1, wherein the shell is precast with metal reinforcing bars extending longitudinally and circumferentially within the thickness of the wall of the shell.

3. A method as claimed in claim 1 or 2, wherein the shell is of circular crosssection.

4. A method as claimed in claim l or 2, wherein the shell is of non-circular crosssection.

5. A method as claimed in claim 4, wherein the shell is of square or rectangular cross-section.

6. A method as claimed in any preceding claim, wherein the floor is of cementitious material.

7. A method as claimed in any preceding claim, wherein the inside surface of the shell is made rough so that it keys with the fresh cementitious material when the latter has hardened.

8. A method as claimed in any preceding claim, wherein an inflatable and deflatable former is used during formation of the inside of the shell, the inflatable and deflatable former being inflated while the inside of the shell is being formed and deflated during a step of extracting the former from the inside of the shell.