GB2038394A - Stressed-skin Reinforced Concrete Stairway Structures - Google Patents
Stressed-skin Reinforced Concrete Stairway Structures Download PDFInfo
- Publication number
- GB2038394A GB2038394A GB7941747A GB7941747A GB2038394A GB 2038394 A GB2038394 A GB 2038394A GB 7941747 A GB7941747 A GB 7941747A GB 7941747 A GB7941747 A GB 7941747A GB 2038394 A GB2038394 A GB 2038394A
- Authority
- GB
- United Kingdom
- Prior art keywords
- construction according
- soffit
- construction
- troughs
- stressed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000011150 reinforced concrete Substances 0.000 title abstract 2
- 238000009415 formwork Methods 0.000 claims abstract description 14
- 238000010276 construction Methods 0.000 claims description 47
- 230000003014 reinforcing effect Effects 0.000 claims description 16
- 239000000463 material Substances 0.000 claims description 12
- 230000008878 coupling Effects 0.000 claims description 3
- 238000010168 coupling process Methods 0.000 claims description 3
- 238000005859 coupling reaction Methods 0.000 claims description 3
- 239000004567 concrete Substances 0.000 abstract description 37
- 230000002787 reinforcement Effects 0.000 abstract description 9
- 238000003466 welding Methods 0.000 abstract 2
- 238000000034 method Methods 0.000 description 6
- 230000009977 dual effect Effects 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000012744 reinforcing agent Substances 0.000 description 2
- 229910000746 Structural steel Inorganic materials 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
- E04F11/00—Stairways, ramps, or like structures; Balustrades; Handrails
- E04F11/02—Stairways; Layouts thereof
- E04F11/022—Stairways; Layouts thereof characterised by the supporting structure
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G13/00—Falsework, forms, or shutterings for particular parts of buildings, e.g. stairs, steps, cornices, balconies foundations, sills
- E04G13/06—Falsework, forms, or shutterings for particular parts of buildings, e.g. stairs, steps, cornices, balconies foundations, sills for stairs, steps, cornices, balconies, or other parts corbelled out of the wall
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G13/00—Falsework, forms, or shutterings for particular parts of buildings, e.g. stairs, steps, cornices, balconies foundations, sills
- E04G13/06—Falsework, forms, or shutterings for particular parts of buildings, e.g. stairs, steps, cornices, balconies foundations, sills for stairs, steps, cornices, balconies, or other parts corbelled out of the wall
- E04G13/062—Falsework, forms, or shutterings for particular parts of buildings, e.g. stairs, steps, cornices, balconies foundations, sills for stairs, steps, cornices, balconies, or other parts corbelled out of the wall for stairs or steps
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
- E04F11/00—Stairways, ramps, or like structures; Balustrades; Handrails
- E04F11/02—Stairways; Layouts thereof
- E04F2011/0203—Miscellaneous features of stairways not otherwise provided for
- E04F2011/0205—Stairways characterised by the use of specific materials for the supporting structure of the treads
- E04F2011/021—Stairways characterised by the use of specific materials for the supporting structure of the treads mainly of stone or stone like materials, e.g. concrete; mainly of glass
- E04F2011/0212—Stairways characterised by the use of specific materials for the supporting structure of the treads mainly of stone or stone like materials, e.g. concrete; mainly of glass mainly of concrete
- E04F2011/0214—Stairways characterised by the use of specific materials for the supporting structure of the treads mainly of stone or stone like materials, e.g. concrete; mainly of glass mainly of concrete cast in situ
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Mechanical Engineering (AREA)
- Forms Removed On Construction Sites Or Auxiliary Members Thereof (AREA)
- Reinforcement Elements For Buildings (AREA)
Abstract
A support structure (1) for use in forming an externally reinforced concrete stairway includes a plurality of elongated C-channels (3) interconnected, preferably by welding to form a unitary body which serves as formwork receiving fluent concrete, and forms a stressed-skin to strengthen the hardened concrete externally. Riser plates 4 are secured to flanges of the C-channels and to brackets 5 by welding. Additional conventional reinforcement may be provided. The staircase is secured to landings by reinforcement or studs projecting from the landing and embedded in or secured to the staircase. <IMAGE>
Description
SPECIFICATION
Externally Reinforced Structures
This invention relates to support constructions for forming externally reinforced structures, such as a concrete stairway.
In prior stairway systems used in conjunction with buildings, it has been common practice to construct a formwork comprised of various elements at a building site to receive concrete and form the stair structure in conjunction with the use of risers. The function of the prior art formworks is primarily directed to the retention and control of the concrete when the structure is being erected. With such techniques, the structural elements of the formwork such as soffits or pans do not make any significant contribution to the structural integrity of the stairway after the concrete has set both in a lateral and longitudinal direction.
To attain sufficient load carrying characteristics, a plurality of elongated reinforcement bars extend through the set concrete to add strength internally to the final stair structure. Thus, much of the strength of the concrete structure is significantly attributable to the reinforcing bars, whereby the bottom formwork which receives the concrete plays little or no structural function. The prior art formwork is either removed from the finished structure or is left merely as an aesthetic covering of the bottom surfaces of the concrete stair or landing.
The use of reinforcement bars as strengthening means in a concrete slab construction has resulted in stairs and landings of sufficient and safe strength, but the utilization of such bars also occasions several disadvantages. Structural steel bars in the form of long rods unnecessarily add weight to the structure and contribute significantly to the overall expense of the stairway or landing being installed. Such added expense results both from the cost of materials and the added labor time required of an installer in erecting the stairway. An important factor therefore which creates the need for such reinforcing rods is that the structure of prior art form-works is not intended or capable of adding structural integrity to the set concrete slab.
According to the present invention there is provided a support construction for use in forming an externally reinforced structure, comprising support means for receiving a settable material in a fluent state for hardening to form a structure, the support means including bottom soffit means arranged to form a stressed skin upon hardening of said settable material whereby to strengthen the structure externally.
The support construction may be used in the manufacture of concrete stairway and landing structure eliminating the necessity of reinforcement bars. If desired, however, reinforcement bars and the like can be included.
As used in connection with the invention of the application, a structure said to have a stressedskin is a load carrying structure whose panei, casing or "skin" carries all or a significant part of the internal stresses resisting an applied load. In the case of a stairway, for example, the applied load would include the weight of the structure itself and any load applied thereto. Stiffening members are generally employed in stressed-skin constructions to give the skin support, shape and stability.
In a preferred embodiment of the invention the soffit means comprises plurality of elongated troughs integraily coupled together to form a unitary body which, upon setting of concrete poured therein, acts as a stressed-skin to add structural strength to the concrete slab in the form of an externally reinforced system. The use of the stressed-skin construction of the invention eliminates the necessity of utilizing costly reinforcing bars in the construction of stairways and landings. The construction of a stairway or landing is more economic due to reduce labor and material costs, since the interconnected soffit troughs function both as an initial formwork in which the concrete forming the structure is poured and retained until set and further contributes to the structural strength of the installation upon setting of the concrete.The bottom walls of the troughs form a stressed-skin while stiffening is contributed by the side walls of the troughs.
The invention also provides an externally reinforced structure formed by use of a support construction according to the invention.
The above and other preferred features of the invention will be apparent from the following description, given by way of example with reference to the accompanying drawings, wherein:
Figure 1 is a perspective illustration of a stair system utilizing a construction according to the invention;
Figure 2 is a partial sectional illustration of a stairway shown in Figure 1;
Figure 3 is a perspective illustration of one of the soffit troughs utilized in the stairway of Figure 1;
Figure 4 is a sectional view taken along line 4-4 illustrating the interconnection of the troughs of the stairway of Figure 1;
Figure 4a is an end view of the troughs showing an improved damming technique of the invention;
Figure 5 is a side schematic illustration with parts in section of the coupling of the stressedskin construction of the invention of a standard prior art structure;;
Figure 6 is another embodiment of the stressed-skin construction of the invention coupled to a standard concrete slab construction;
Figure 7 is still another embodiment of the stressed-skin construction of the invention coupled to a conventional platform having reinforcement bars;
Figure 8 is another embodiment of the stressed-skin construction of the invention coupled to a landing at its top;
Figure 9 is a schematic side illustration of the stressed-skin construction of the invention
coupled at its bottom to a landing;
Figure 10 is a partial side perspective
illustration of still another embodiment of the
stressed-skin construction of the invention; and
Figure 11 is a partial end sectional illustration of the embodiment of Figure 10.
Description of a Preferred Embodiment
Referring now to Figure 1 , there is shown one
embodiment of a concrete slab structure having
the stressed-skin construction according to the
invention. Although the invention is shown and
described with reference to use with a concrete
slab structure utilized in a stairway system of a
building, the technique of the invention of utilizing
a stressed-skin construction is not intended to be
limited to such an application since it can be used
in conjunction with various types of concrete slab
structures for numerous applications.
The externally reinforced structure 1 of the
invention shown in Figures 1, 2 and 4 is in the form of a stairway having a pair of stringers 2, one
of which is illustrated. Structure 1 is a unitized
construction having a plurality of pan-like, soffit
troughs 3 of a suitable metal affixed together as a
single body. The plurality of troughs 3 have
elongated bodies to substantially span a desirsd dimension such as, for example, between a floor
and a landing, floor to floor or numerous other
well known situations. Elongated troughs 3 are in
contact with each other in a side by side
arrangement and are welded together or
otherwise secured by any suitable method of
attachment to create a rigid one piece body.
Troughs 3 are in the form of a C-channel which includes two parallel sidewalls 3a having flanges 3b extending perpendicular thereto. The outer surface of the sidewalls 3b is secured in flush
contact with the sidewall of an adjacent trough,
whereby the two affixed walls 3a rigidize the
unitary soffit trough structure created by the
plurality of elements. Although the outer surface
of adjacent walls 3a are in flush contact as shown
in Figures 1 and 4, it should be recognized that the walls 3a may be angularly disposed to each
other and be affixed at the point of contact, such
as created by alternate cross sections of the C
channels.
The tops of the troughs 3b are adapted to be
coupled to plurality of riser plates 4 as shown in
Figure 1 supported by means of a suitable number
of brackets 5 welded respectively to soffit 3 and
riser 4. Soffit troughs 3 and stringer 2 create a
continuous bottom wall to receive and control fluent concrete through the use of an inwardly
directed flange 6 formed on the bottom of
stringers 2, partially projecting under structure 1.
From the foregoing description, it should be
apparent that the pair of stringers 2, soffit troughs
3 being integrally interconnected, and risers 4 form a structure which when erected at the job
site acts as a formwork to receive a settable -material in a fluent state such as unhardened concrete. Upon setting of the concrete as a slab structure, the bottom of soffit 3 formed by the bottom wall 3' becomes a stressed-skin structure carrying internal stresses of the applied load which adds significant structural integrity and strength both laterally and longitudinally to the concrete slab which it supports eliminating the necessity of reinforcing bars required by the prior art. Thus, the integrally coupled soffits perform the dual function of being a formwork and structural component to support the applied load as an external reinforcing agent.If benefit of both the stressed-skin construction of the invention and reinforcing bars is desired, both can be incorporated in the same concrete slab for extra strength in unusually heavy load situations or extreme length.
Referring to Figure 5, there is illustrated another embodiment of the improved stressedskin construction of the invention which demonstrates that the novel stressed-skin stairway herein described is capable of being interconnected with a standard landing having conventional reinforcing bars. Specifically, externally reinforced structure 1 and stringer 2 are connectable to standard slab construction such as landing 20 which possesses a plurality of reinforcing bars 21 for its strength. Reinforcing rod 21 extends at its lower end 21 a into a bracket 22 having a suitable notch to receive the reinforcing bar. Bracket 22 acts as an additional mechanical connection between the bar and the lower portion of the stairway.In such situations, landing 20 may be constructed by conventional techniques using formworks and the like whereby upon setting of the poured concrete a suitable tie between landing 20 and the system of the present invention is achieved with the extension of reinforcing bars into the structure 1 as shown.
It has been found that such adequate strength without other elements is created by such attachment of the stressed-skin system having troughs 3 to the conventional reinforcement bars extending from landing 21. This interconnection allows the stressed-skin construction of the invention to be utilized in conjunction with conventional platforms and stairs.
Referring to Figure 6, there is illustrated still another embodiment of the invention. The embodiment of Figure 6 is similar to that described with reference to Figure 5, except that the conventional landing 30 of concrete includes a pair of reinforcing bars which extend downward into the stressed-skin stairway system of the invention. When concrete is poured into the stairway system, a union of suitable strength is created.
Referring to Figure 7, there is illustrated another technique of utilizing the stressed-skin stairway system of the invention by which the landing is formed at the bottom of the stairway system, and reinforcement bars 41 extend upward into the stressed-skin system of the invention for suitable coupling.
Referring to Figures 8 and 9, there are illustrated other uses by which the stressed-skin system of the invention may be coupled above to a landing 50 of concrete by the use of conventional stud 51 or below to a landing 60 by stud 61.
Referring now to Figures 10 and 1 there is shown another embodiment of the concrete slab structure having the stressed-skin construction according to the invention. The embodiment of
Figures 10 and 11 is similar to the embodiment described with reference to Figures 1 to 4 with the exception that the stringers are eliminated illustrating the externally-reinforced and selfsupporting properties of the stressed-skin construction of the invention.
The externally reinforced structure of the invention shown in Figures 10 and 11 is shown used as a stairway and is formed in a unitized construction having a plurality of pan-like, soffit troughs 3' of a suitable metal affixed together as a single body self-supporting unit. The plurality of troughs 3' have elongated bodies to substantially span a desired dimension such as, for example, between a floor and a landing, floor to floor or numerous other well known situations. Elongated troughs 3' are in contact with each other in a side by side arrangement and are welded together or otherwise secured by any suitable method of attachment to create a rigid one piece body.
Troughs 3' are in the form of a C-channel which includes two parallel sidewalls 3a' having flanges 3b extending perpendicular thereto. The outer surface of the sidewalls 3b' is secured in flush contact with the sidewall of an adjacent trough, whereby the two affixed walls 3a' rigidize the unitary soffit trough structure created by the plurality of elements. Although the outer surfaces of adjacent walls 3a are in flush contact as shown in Figures 1 to 4, it should be recognized that the walls 3a' may be angularly disposed to each other and be affixed at the point of contact, such as created by alternate cross sections of the Cchannels.
The tops of the troughs 3b' are adapted to be coupled to a plurality of riser plates 4' as shown in
Figure 10 supported by means of a suitable number of brackets 5' welded respectively to soffit 3' and riser 4'. Soffit troughs 3t create a continuous bottom wall to receive and control fluent concrete.
From the foregoing description, it should be apparent that soffit troughs 3 being integrally interconnected, and risers 4 form a structure which when erected at the job site acts as a formwork to receive a settable material in a fluent state such as unhardened concrete. Upon setting of the concrete as a slab structure, the bottom of soffit 3 formed by bottom wall 3' becomes a stressed-skin structure carrying internal stresses of the applied load which adds significant structural integrity and strength both laterally and longitudinally to the concrete slab which it supports eliminating the necessity of reinforcing bars, stringers and other external support members required by the prior art. Thus, the integrally coupled soffits perform the dual function of being a formwork and structural component to support the applied load as an external reinforcing agent.If benefit of both the stressed-skin construction of the invention and reinforcing bars is desired, both can be incorporated in the same concrete slab for extra strength in unusually heavy load situations or extreme length. In the embodiment of Figures 1 to 4, the stringers are used for purely aesthic or conventional reasons, but are not needed to support the concrete slab construction because of the self-supporting stressed skin structure of the invention. As shown in Figures 10 and 11, the stressed-skin construction of the invention does not require stringers since the load is carried by troughs 3' integrally coupled as a unit to support the load.
While the invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the
Claims (14)
1. A support construction for use in forming an externally reinforced structure, comprising support means for receiving a settable material in a fluent state for hardening to form a structure, the support means including bottom soffit means arranged to form a stressed skin upon hardening of said settable material whereby to strengthen the structure externally.
2. A construction according to claim 1, wherein said soffit means comprises a plurality of elongated elements affixed together to form a unitary body.
3. A construction according to claim 2, wherein said elements comprise a plurality of elongated troughs.
4. A construction according to claim 3 wherein the troughs are generally C-shaped in crosssection and have substantially parallel walls.
5. A construction according to claim 4, wherein the troughs are disposed side by side and have their adjacent side walls fixed together.
6. A construction according to claim 4 or 5, wherein the sidewalls of the troughs have edge portions which are turned inwardly.
7. A construction according to any one of claims 2 to 6, wherein the unitary body is supported by a pair of stringers for forming a stair structure.
8. A construction according to claims 6 and 7, wherein the risers are supported on the inturned edge portions.
9. A construction according to claim 7 or 8, including at least one reinforcing bar extending
into a portion of the length of the unitary body for
coupling the structure to a structure in which said
at least one bar is embedded.
10. A support construction for use in forming
an externally reinforced structure comprising a plurality of elongated soffit members of channel section and each having a bottom wall and a pair of spaced sidewalls integral with the bottom wall, said soffit members being coupled together to form a unitary support body for acting as a formwork to receive settable material in a fluent
state, and forming a stressed skin providing
lateral and longitudinal strength to said material upon setting, the bottom wall of each soffit
member acting as a stressed skin element.
1 A construction according to claim 10 wherein the sidewalls of each soffit member lie in
planes disposed substantially perpendicular to the
bottom wall thereof.
12. A construction according to claim 10 or 11 wherein contacting sidewalls of the soffit members are connected together to form said unitary body.
13. A construction according to claim 1, 10, 11 or 12, wherein there are at least three soffit members.
14. A construction according to any one of claims 10 to 13, wherein the sidewalls of the soffit members have inturned edge portions which support risers for forming a stair structure.
1 5. A construction according to any one of claims 10 to 14, including at least one reinforcing bar in spaced relation to said plurality of soffit members for extending into a portion of said settable material to couple said structure to a structure in which said at least one reinforcing bar is embedded.
1 6. A support construction for use in forming an externally reinforced structure, substantially as herein described with reference to the drawings.
1 7. An externally reinforced structure formed by use of a construction as claimed in any one of the preceding claims.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US96798778A | 1978-12-04 | 1978-12-04 | |
| US06/086,919 US4250672A (en) | 1979-10-22 | 1979-10-22 | Externally reinforced concrete stairs |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2038394A true GB2038394A (en) | 1980-07-23 |
| GB2038394B GB2038394B (en) | 1982-11-24 |
Family
ID=26775305
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7941747A Expired GB2038394B (en) | 1978-12-11 | 1979-12-04 | Stressed-skin reinforced concrete stairway structures |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU5343979A (en) |
| CA (1) | CA1124543A (en) |
| GB (1) | GB2038394B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2663069A1 (en) * | 1990-06-06 | 1991-12-13 | Fournel Joel | Prefabricated module permitting the production of a stairway step without any special tooling equipment |
| WO1998057010A1 (en) * | 1997-06-11 | 1998-12-17 | Stairform Designs Pty. Ltd. | Staircase form |
| FR2935412A1 (en) * | 2008-09-04 | 2010-03-05 | Dsn Design Service Network | Permanent formwork for realization of poured concrete staircase in swimming pool, has primary walls secured to secondary walls to brace and maintain primary walls in vertical position for forming compartments filled with poured concrete |
| GB2534033A (en) * | 2015-01-06 | 2016-07-13 | Flight Products Ltd | Casting concrete steps or stairs |
| CN107178185A (en) * | 2017-07-25 | 2017-09-19 | 佛山市正轻钢房屋有限公司 | The permanent template system and manufacture method of concrete staircase |
| CN113070624A (en) * | 2021-04-09 | 2021-07-06 | 碧源建工有限公司 | Regularization steel stair welding frock of marking time |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111719851B (en) * | 2020-06-29 | 2025-06-27 | 中冶天工集团天津有限公司 | A chiseling-free device for stair joints and formwork construction method thereof |
-
1979
- 1979-12-03 CA CA341,081A patent/CA1124543A/en not_active Expired
- 1979-12-04 GB GB7941747A patent/GB2038394B/en not_active Expired
- 1979-12-04 AU AU53439/79A patent/AU5343979A/en not_active Abandoned
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2663069A1 (en) * | 1990-06-06 | 1991-12-13 | Fournel Joel | Prefabricated module permitting the production of a stairway step without any special tooling equipment |
| WO1998057010A1 (en) * | 1997-06-11 | 1998-12-17 | Stairform Designs Pty. Ltd. | Staircase form |
| FR2935412A1 (en) * | 2008-09-04 | 2010-03-05 | Dsn Design Service Network | Permanent formwork for realization of poured concrete staircase in swimming pool, has primary walls secured to secondary walls to brace and maintain primary walls in vertical position for forming compartments filled with poured concrete |
| GB2534033A (en) * | 2015-01-06 | 2016-07-13 | Flight Products Ltd | Casting concrete steps or stairs |
| CN107178185A (en) * | 2017-07-25 | 2017-09-19 | 佛山市正轻钢房屋有限公司 | The permanent template system and manufacture method of concrete staircase |
| CN113070624A (en) * | 2021-04-09 | 2021-07-06 | 碧源建工有限公司 | Regularization steel stair welding frock of marking time |
| CN113070624B (en) * | 2021-04-09 | 2022-07-26 | 碧源建工有限公司 | Regularization steel stair welding frock of marking time |
Also Published As
| Publication number | Publication date |
|---|---|
| AU5343979A (en) | 1980-06-12 |
| GB2038394B (en) | 1982-11-24 |
| CA1124543A (en) | 1982-06-01 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |