US20030089050A1

US20030089050A1 - Apparatus and method for improving quality of elevated concrete floors

Info

Publication number: US20030089050A1
Application number: US10/256,757
Authority: US
Inventors: Eldon Tipping; Philip Quenzi; Russ Stein; Mark Pietila; Carl Kieranen
Original assignee: Delaware Capital Formation Inc
Current assignee: Somero Enterprises Inc
Priority date: 2001-09-28
Filing date: 2002-09-27
Publication date: 2003-05-15
Also published as: CA2405877A1

Abstract

A device and method for measuring an initial camber of a beam includes a support member positionable at a beam of a structure. The support member includes a laser receiver for receiving a laser reference plane at a first location when the support member is positioned at an end of the beam and at a second location when the support member is positioned at a central region of the beam. The initial camber of the beam is then derived by determining a difference between the first and second locations on the laser receiver. A loose shoring system provides an adjustable length support section and a positive stop for limiting deflection of the beam at a desired amount generally equal to the measured initial camber of the beam. The stop is adjustable to set a gap approximately equal to the expected deflection or initial camber of the beam as desired.

Description

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority of U.S. provisional application, Ser. No. 60/325,984, filed Sep. 28, 2001 by Tipping et al. for APPARATUS AND METHOD FOR IMPROVING QUALITY OF ELEVATED CONCRETE FLOORS, which is hereby incorporated herein by reference in its entirety.[0001]

FIELD OF THE INVENTION

The present invention relates generally to a method for placing concrete on elevated decks and surfaces and, more particularly, to a method for allowing the placing and screeding of concrete to form the elevated concrete slabs which result in substantially flatter and more level floor surfaces of substantially uniform thickness.

BACKGROUND OF THE INVENTION

Steel beams and girders, which are designed and then assembled together to form a support structure, are commonly used to create elevated decks and floors, such as for multistory buildings and the like. Typically, the horizontal steel I-beams are often specified by the building designers to be pre-cambered or arched or curved slightly to have an upwardly curved initial form. This is done in an effort to anticipate the normal, expected deflection of the beams, and to counteract the strain of the floor loads that they are designed to support. To form the elevated floor, corrugated sheet metal decking material is typically placed over the horizontal I-beams and girders. Steel bars and wire mesh may be laid out in designated patterns over the corrugated decking to serve as reinforcement. This material is normally supported on small supports or “chairs” to ensure that it is held at the correct height within the concrete as the concrete cures. The addition of and location of these materials add greatly to the strength of the final product.

Concrete is then placed and screeded over the arrangement to form a slab of the specified thickness. Typically, the specified camber of the beams and girders is 80% of the estimated deadload deflection. For example, for a typical beam having an unsupported span of thirty feet (9.14 m), the load deflection may be approximately one inch (25.4 mm) to one and one half inches (38.1 mm) at the center of the beam. An approximate deflection tolerance range of plus approximately one-half inch (13 mm), or minus approximately zero inches may be typical. Often, the beams may not deflect as much as anticipated under the design load, or the beams may deflect beyond what is expected. The ideal amount of deflection is that which allows the production of a flat and level concrete floor of uniform thickness.

As the reinforcement materials and concrete are placed over the corrugated metal decking, the mid sections of the beams and girders deflect downward under the weight of the materials. With the variables involved in estimating the required camber in the beams, and the variable nature of the actual deflection of the beams under load, each contribute to complicate the usefulness and accuracy of using known concrete screeding methods on decks. Conventional methods of screeding which are used to strike off, level, and otherwise smooth the concrete, often result in a floor that is either not flat, not level, or not of uniform thickness. In extreme cases, all three desired specifications are compromised in the final outcome, resulting in an inferior quality floor.

In order to counteract an excessive amount of camber in the horizontal I-beams, concrete is often pre-placed within each bay (the area enclosed by four adjacent columns) to cause an initial anticipated downward deflection of the beams and girders. It is then possible to strike-off the concrete to a uniform thickness over the sheet metal decking. However, when enough concrete is added to ensure an adequate amount of material for the strike off process, the excess weight may cause an over-deflection of the support structure in certain areas. This results in low areas of the floor caused by over deflection of the support structure, which may not again recover even after the concrete is stuck off to a uniform thickness. Should more concrete be added to fill in these low areas, the additional weight may cause further deflection of the support structure. This results in a slab or floor which is perhaps more flat and level, but is now no longer of uniform thickness. This also consumes more concrete and adds to the cost of materials.

One commonly proposed method to obtain a uniform thickness of concrete on an elevated deck is to use pre-fabricated metal structures or stands that have support legs which rest directly on the corrugated sheet metal decking. A small plate is held in position at the desired concrete thickness above the metal deck. The screeding process then relies on these stands as a height gauge. Some devices may even ride along the top surface of the stands, similar to the methods used for slabs on grade, prior to implementation of mechanized laser screeding. The stands may later be removed before the concrete cures and the remaining holes are filled and refinished.

Another method of obtaining a uniform thickness of concrete on an elevated deck is to provide an ongoing series of small pre-screeded areas ahead of the actual screeding process. A hand trowel is used to strike off a roughly twelve inch (30 cm) diameter area of the pre-placed concrete. The height of each wet screed pad is determined by using a pre-established laser transmitter set-up at the site, and a hand-held laser receiver mounted to a grade-stick. These “wet screed pads” are created at the desired thickness of concrete as a height gage. A hand-screeding method will use these pads as a reference. First, two pads are made about ten feet apart. Then, a 2×4 or similar straight edge is used to strike off approximately a 12 inch (30 cm) wide by 10 foot (3 m) long surface between the two twelve inch (30 cm) diameter pads. Two of these 12 inch (30 cm) wide by 10 foot (3 m) long “surface-pads” are then struck off parallel to each other at a distance roughly equal to the width of the handheld screed being used. The concrete is then struck off between these two parallel surfaces using the “surface-pads” as guides for the hand held screed. Excess material must be raked and shoveled away by at least one and often two or more workers. Low spots as well must be filled in by the workers, prior to the action of the hand-screed.

While either of these strike-off methods may provide a floor or slab of generally uniform thickness on a supported deck, these methods often result in over-deflection of the beams due to the excess weight of concrete being placed in the bays prior to the screeding process (concrete weighs approximately 137 lbs. per cubic foot (2194.7 kg/cubic meter)). Since the concrete must be “placed high” to assure that there is enough material before screeding, over-deflection of the beams and support structure can result in a bay which has a low area in the center. This is referred to as “ponding” in the industry. To counteract ponding, additional concrete has to be placed in the center area to bring the slab back up to the specified grade and eliminate the ponding effect. This solution, however, may result in substantially more concrete being used to accomplish the desired result, as well as a slab that is not of uniform thickness. In some cases, this solution to ponding may result in up to 30% more concrete usage, adding significantly to the cost of the construction project.

In order to counteract the ponding effect of a floor, in a most basic way, 4×4 inch (10×10 cm) wood shores or support posts may be temporarily placed vertically as columns between the beams and girders of the floor or slab under construction and the finished floor below. Shoring posts have been used for many years in the construction industry as temporary columns used to help support building materials such as formwork and corrugated decking while the concrete is in the process of being placed and cured. There are a wide variety of shoring posts available in the industry. Some are simple wood or metal posts, which are chosen in size for a cross-sectional load carrying capacity and are simply cut to the desired length. Specially designed adjustable shoring posts are also available. These posts may utilize screw-jack threads or telescopic sections with various types of locking mechanisms or through-pins. Overall lengths for all posts may vary widely, typically depending upon the need, such as from approximately 7 feet (2.13 m) or less to as much as approximately 15 feet (4.57 m) or more. The more specialized shores can be joined together using mechanical elements both vertically and horizontally to create supports of added height, capacity, and stability.

The shoring posts help to support the beams and girders of the subject floor as they become loaded. The shores are simply cut to length and fitted between the cambered beams and the finished level below. In some cases, the shores may be selected and installed to provide a small gap between the shores and the beams. With current methods, the gap is estimated or roughly measured to be approximately equal to the amount of designed initial camber of the beam at each particular location. In this way, the shoring columns are expected to limit the estimated deflection of the beams and girders, and enhance the finished surface of the floor itself. However, the shores must be secured to the beam or support surface or otherwise held in place to prevent the shore from falling over during the placing process until the beam has deflected sufficiently so that the shore is pressed between the beam and the lower support surface. It is also difficult to accurately measure the amount of camber in the beams and to set the shore length appropriately.

Under ideal conditions, if the beams are pre-cambered perfectly, and the correct weight of reinforcing materials and concrete are added to cause the beams to deflect downward to the desired grade, the final surface of the floor can more easily be made to be flat, level, and of uniform thickness. When this occurs, all three desired specifications can be more easily achieved, resulting in a higher quality floor installed at or near the estimated cost. Unfortunately, ideal conditions are not always available to allow this to occur with consistency.

Accordingly, there is a need in the art for an improved method and tools for providing a flat, level decking of uniform thickness. The method should employ the correct amount of pre-camber needed for the horizontal I-beams. The tools should provide a means to verify the elevation position of each beam in their respective installed locations, and provide a means to set-up and accurately install an improved temporary shoring to limit beam deflection at various support locations along the beams. The improved temporary shoring preferably should remain in place until the concrete on the floor above has been struck-off, finished, and allowed to cure to the desired strength. The method and tools should consistently account for the pre-camber in the beams and help provide flat and level elevated concrete floors of uniform thickness, high quality, and predictable cost.

SUMMARY OF THE INVENTION

The present invention is intended to provide a loose shoring system which sets a basis to improve the quality of any concrete floor which is installed and supported by elevated steel beams, girders, and decking materials. This is accomplished by anticipating and measuring the camber in the beams or supporting members, and limiting the final deflection of the supporting members of the floor where it is possible to do so. The shoring system of the present invention consists of both methods and tools which ultimately leads to higher quality concrete floors of a desired flatness and consistent thickness than has been typically achieved in the elevated deck and multi-floor construction industry. This invention is a sum combination of improvements in existing tools, support work and on site measurements, and application of laser-based measurement technology, and may be used to provide feedback to structural engineers for development of architectural structural specifications.

According to a first aspect of the present invention, a loose shoring system for controlling a degree of deflection of a beam of a structure includes an adjustable shoring device which is adjustable in length and positioned between a generally central portion of the beam and a support surface below the beam. The adjustable shoring device includes a positive stop to limit downward deflection of the beam at a desired point. The amount of deflection allowed is preferably approximately equal to an initial amount of camber or upward curvature in the beam prior to placing concrete on the deck or surface above the beam. The adjustable shoring device is adjustable in length such that it may be placed snuggly between a lower surface of the beam and the lower support surface prior to any downward deflection of the beam, in order to remain in place without any additional bracketry or supports prior to placing the concrete. The adjustable shoring device is then adjustable in length or compressible to allow for a predetermined amount of downward deflection of the beam as concrete is placed on the deck or surface above the beam. Preferably, a plurality of shoring devices may be placed beneath a plurality of beams and/or girders. Additionally, multiple shoring devices may be positioned at different locations along one or more beams and girders.

According to another aspect of the present invention, a device, system and method for measuring the height of the top of an I-beam functions in relation to an established laser plane reference. The I-beam height measurement device is used to determine the actual amount of pre-camber at various places along the length of a beam. It is also used to establish height relationships between various horizontal beams at their respective end points, where they are attached to vertical columns. The purpose for this is to establish whether or not the beams are at the correct elevation. If not, this would provide measured data to on-site workers, who can then decide on an ideal average for the finished grade, according to the desired floor specifications as it is created from poured concrete or like materials.

According to another aspect of the present invention, a measuring system for measuring an initial camber in a beam comprises a laser reference generator operable to generate a laser reference, a laser receiver operable to receive the laser reference, and a support member. The laser receiver is positionable on the support member, which has an end adapted to removably mount to a portion of the beam. The laser receiver is positionable on the support member to receive the laser reference at a first location when the support member is positioned at an end portion of a beam. The laser receiver is operable to receive the laser reference at a second location when the support member is positioned at a generally central portion of the beam. The measuring system is configured such that a vertical distance between the first and second locations defines the initial camber in the beam.

In one form, the end of the support member is adapted to removably mount to an upper surface of the beam, such that the support member hangs downward from the upper surface of the beam.

Preferably, the support member comprises an adjustable support member which is adjustable in length to adjust a position of the laser receiver relative to the end of the support member. Optionally, the laser receiver is adjustably positioned on the support member and is adjustable relative to the end of the support member to position the laser receiver to receive the laser reference at the first location.

According to another aspect of the present invention, a method for measuring an initial camber or curvature of a beam supported at opposite ends comprises positioning a laser receiver at a beam, generating a laser reference at a preset level and comparing a first distance between an end portion of the beam and the preset level with a second distance between a generally central portion of the beam and the preset level. An initial camber of the beam at the generally central portion is determined by determining a difference between the first and second distances.

In one form, the method includes positioning the laser receiver at a support member and positioning the support member at an end portion of the beam. The laser receiver receives the laser reference at a first receiving location on the laser receiver when the support member is positioned at an end portion of the beam. The first distance is defined between the end portion of the beam and the first receiving location on the laser receiver. The method may include positioning the support member at a generally central portion of the beam and receiving the laser reference at a second receiving location on the laser receiver when the support member is positioned at the generally central portion of the beam. The second distance is defined between the generally central portion of the beam and the second receiving location on the laser receiver. The difference between the first and second distance is then determined by determining a vertical distance between the first and second receiving location on the laser receiver.

Optionally, the method may include supporting the generally central portion of the beam to limit deflection of the beam beyond a predetermined amount while the beam is loaded. The predetermined amount is approximately equal to the difference between the first and second distances. Preferably, an adjustable support device is provided which includes an adjustable support section, a biasing member for biasing the support section toward an extended position and a positive stop member. The adjustable shoring device is positioned at the generally central portion of a beam and between a lower surface of the beam and the support surface. The biasing member extends the support section to retain the support section between the lower surface of the beam and the support surface. An initial gap of the positive stop member is set to be approximately equal to the predetermined amount.

The method may include placing uncured concrete on the beams while the adjustable support device is positioned at the generally central portion of the beam and limiting downward deflection of the beam with the positive stop member when the beam has deflected the predetermined amount in response to the placing of the uncured concrete. The adjustable support device may then be removed from the generally central portion of the beam after the placed concrete has at least partially cured.

According to yet another aspect of the present invention, an adjustable shoring device is adjustable in length and positionable between a generally central portion of a beam and a support surface below the beam. The adjustable shoring device is configured to limit downward deflection of the beam to a predetermined amount while the beam is loaded and includes a telescoping support section, a biasing member and a positive stop. The support section is extendable and compressible to adjust an overall length of the support section and is positionable at a generally central portion of a beam and between a lower surface of the beam and the support surface. The biasing member biases the support section toward an extended position to generally removably secure the support section in place between the lower surface of the beam and the support surface. The biasing member is compressible to allow compression of the support section toward a compressed position. The positive stop limits compression of the support section and defines an initial gap. The support section, the biasing member and the initial gap are compressible in response to loading and downward deflection of the beam. The positive stop limits compression of the support section when the initial gap is closed.

Therefore, the present invention provides a measurement device and method which provides an accurate measurement of an initial camber of a beam of an elevated deck or surface. The measurement device is operable in response to or in conjunction with a laser plane reference and provides an easy and accurate measurement of the initial camber of the beams. The present invention also provides for a loose shoring device or system which is operable to temporarily shore or support a generally central portion of a beam while concrete is placed thereon. The shoring device is secured in place between the beam and the lower support surface and allows downward deflection of the beam to a generally level orientation, while limiting or substantially precluding further downward deflection beyond the generally level orientation. The present invention thus provides a measuring and shoring system which is operable to determine the initial camber of a beam and to limit deflection of the beam to that amount as concrete is placed thereon.

These and others objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of multiple adjustable shoring columns in accordance with the present invention, as implemented on a plurality of beams and girders of a single elevated bay; [0027]
FIG. 2 is perspective view of one of the adjustable shoring columns of FIG. 1; [0028]
FIG. 3 is an upper perspective view of the adjustable shoring device of FIGS. 1 and 2; [0029]
FIG. 4 is a lower perspective view of the adjustable shoring device of FIGS. [0030] 1-3;
FIG. 5 is a side elevation of the adjustable shoring device of FIGS. [0031] 1-4, showing an initial gap at a stop member of the shoring device;
FIG. 6 is another side elevation of the adjustable shoring devices of FIGS. [0032] 1-5, showing an initial gap approximately equal to the beam camber;
FIGS. 7A and 7B are side elevations and partial sectional views of the adjustable shoring device of FIGS. [0033] 1-6, as implemented at a center region of a beam;
FIG. 8 is a side elevation of a camber measurement device in accordance with the present invention; [0034]
FIG. 9 is a sectional view of an adjustable attachment assembly for use with a conventional shore member in accordance with the present invention; [0035]
FIGS. 10A and 10B are side elevation and partial sectional views of the adjustable attachment of FIG. 9, as implemented at a lower end of a conventional shoring column; [0036]
FIGS. 11A and 11B are side elevation and partial sectional views of the adjustable attachment of FIG. 9, as implemented at an upper end of a conventional shoring column; [0037]
FIG. 12 is a side elevation and partial sectional view of another adjustable attachment assembly similar to that of FIG. 9, and including an indicator assembly thereon; and [0038]
FIG. 13 is a side elevation and partial sectional view of a mid-mount adjustable attachment assembly in accordance with the present invention, which mounts to a middle region of an existing shoring post.[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and the illustrative embodiments depicted therein, a loose shoring [0040] system 10 is positioned at the beams 12 and girders 14 of an elevated flooring bay 16 in a newly constructed high-rise or other building (FIG. 1). One or more bays define the building or structure. Each bay 16 is defined by a plurality of vertical I-beams or columns 18 which support the ends 12 a, 14 a of the beams 12 and girders 14 about the perimeter of the bay. The structure may be a building which comprises multiple levels, such that the vertical columns 18 support a level of beams 12 and girders 14 above one or more lower levels or above a support surface 20 (which may be a floor or slab as shown in FIGS. 5 and 6 or an elevated deck as shown in FIGS. 1, 7A, 7B, 10A, 10B, 11A and 11B). A corrugated metal deck 22 or the like is placed over the beams and girders of each bay prior to placing concrete at or in the bay. An angle iron 24 or the like is provided around the perimeter of the targeted area to contain the concrete at the edges of the slab. The loose shoring system of the present invention is applicable to conventional beams 12 and girders 14, which are typically I-beams. Although the shoring system of the present invention is applicable to both beams and girders of the bays of a building, for the sake of brevity and clarity the following discussion refers to the shoring system of the present invention only as being implemented at one or more beams. This is intended to refer to both the beams and girders of each bay of the building or structure, since the shoring system of the present invention is equally applicable to both the beams and girders of the structure. The I-beams are often initially cambered such that they have an initially upwardly curved center region 12 b, 14 b, which roughly approximates a normal mid-section deflection of the beams under load stress and strain between their fixed ends 12 a, 14 a as the concrete is placed on the deck surface of the respective bays.
Loose shoring [0041] system 10 includes one or more adjustable shoring devices 26 positioned beneath one or more of the beams 12 of the building or structure. The adjustable shoring devices are positioned between a lower surface 12 c (FIGS. 1, 7A, 7B, 10A, 10B, 11A and 11B) of the beam 12 and the support surface or floor 20. The adjustable shoring devices 26 are operable to snuggly fit between the lower surface 12 c of the beams 12 and the support surface 20, yet are compressible to allow for a predetermined amount of deflection of the beam as concrete is placed and cured thereon. The adjustable shoring devices 26 further provide a positive stop 43 to limit their compression and, thus, to limit deflection of the beams, at the predetermined amount. This limits or substantially precludes over deflection of the beams, which may result in ponding or other problems with the concrete that is poured and cured on the deck surface on top of the beams. Each adjustable shoring device 26 may include a laser receiver 28 for receiving a laser beam from a laser plane generator 30, which may be a column mounted laser transmitter positioned at one of the vertical columns 18 or an otherwise supported laser transmitter positioned at a tripod or other support 30 a at the building or structure. The laser plane generator 30 and receivers 28 provide for proper positioning and adjusting of the adjustable shoring devices to ensure that the beams deflect the appropriate amount when the concrete is placed and cured above the beams, as discussed in detail below.
As best shown in FIGS. [0042] 2-6, 7A and 7B, adjustable shoring device 26 includes a telescoping post or tube or support section 32, which includes an inner tube or support section 32 a and an outer tube or support section 32 b. Inner tube section 32 a is slidably received through a receiving end 32 e of outer tube section 32 b and is slidable and adjustable or movable within outer tube section 32 b. A biasing member or compression spring 34 (FIGS. 2, 3, 5, 6, 7A and 7B) is positioned within outer tube 32 b and functions to bias inner tube 32 a toward an extended position. A spring stop pin or reaction pin 36 is positioned through one of a plurality of holes 32 c through outer tube 32 b to hold one end of the compression spring 34 in position within the outer tube 32 b. An end of inner tube 32 a within outer tube 32 b then pushes against the compression spring 34, whereby the compression spring 34 compresses or extends as the overall length of tube 32 is adjusted via movement of inner tube 32 a within outer tube 32 b. The telescoping tubes may be formed from any known type of tubing, and may be circular or square in cross section or may be other shapes as desired. The outer tube 32 b is a hollow tube for receiving the inner tube 32 a therein, while the inner tube may be hollow or solid and may include an end plate for engaging the compression spring, in order to prevent the spring from sliding within the inner tube.
Adjustable shoring [0043] device 26 preferably further includes an adjustable pull down handle 38, which is fixedly mounted or secured to outer tube 32 b, such that manual movement of handle 38 by an operator functions to compress compressible spring 34 to shorten the length of adjustable shoring device 26. At opposite ends of the telescoping tube 32 are a pair of bearing pads or base and top plates 35 a, 35 b, for bearing against the lower support surface 20 and the lower surface 12 c of the beam 12, respectively.
Adjustable shoring [0044] device 26 further includes the positive stop or stop member 43, which preferably includes a screw adjustable collar 40, which is threadedly positioned at a threaded portion or threads 32 f (FIGS. 7A and 7B) of a receiving end 32 e of outer tube 32 b and extends downwardly therefrom to provide a stop collar at a lowermost portion of receiving end 32 e of outer tube 32 b. Although shown as being at a lowermost portion of outer tube 32 b, clearly, telescoping tube 32 could be reversed such that stop collar 40 is positioned at an uppermost portion of a lower, outer tube, without affecting the scope of the present invention. The positive stop 43 further includes a stop pin 42 positioned through a selected pair of holes 32 d through inner tube 32 a, such that a lower end of adjustable collar 40 contacts stop pin 42 to limit or stop further compression of the tubes 32 and spring 34 after the beam and adjustable shoring device have deflected and moved the selected amount, as discussed below.
During use and operation of adjustable shoring [0045] device 26, adjustable shoring device 26 is positioned beneath a beam 12, such as in a generally central portion 12 b of the beam, or spaced along the beam, depending on how many adjustable shoring devices are desired along a particular beam. In order to position the adjustable shoring device 26 at the beam, the pull down handle 38 is pulled or moved downwardly to compress compressible spring 34 within tube 32, in order to shorten the overall length of adjustable shoring device 26, such that it may easily be positioned between the lower surface 12 c of the beam 12 and the support floor 20. When adjustable shoring device 26 is positioned at the appropriate location beneath the beam, the handle 38 is released to allow the spring 34 to expand and, thus, to allow the overall length of the adjustable shoring device 26 to increase until adjustable shoring device 26 is positioned tightly between the lower surface 12 c of the beam 12 and the support surface 20 (as shown in FIG. 7A). The spring pin 36 may be moved or adjusted along the holes 32 c in outer tube 32 b to adjust the amount of compression in spring 34 and thus the amount of force it may take to position or move the adjustable shoring device once it is positioned beneath the beam. Once in position, stop pin 42 is positioned in the openings 32 d in inner tube 32 a which are closest to or at an appropriate distance from the lower end of the adjustable collar 40. The amount of vertical offset of the beam from horizontal due to the initial camber in the beam is then determined and a gap 41 (FIGS. 6 and 7A) between the adjustable collar 40 and pin 42 is set to be approximately equal to the initial amount of the vertical offset or camber (shown as DIM A in FIG. 7A). The gap 41 is adjusted by rotating collar 40 around the threaded portion of outer tube 32 b, whereby collar 40 moves up or down along threaded portion 32 f of receiving end 32 e of outer tube 32 b.
As concrete is placed on the [0046] deck surface 22 above the beams 12, the beams supporting the deck surface begin to deflect downward toward a horizontal position. As the beams deflect downward, the compression spring 34 compresses to allow the overall length of adjustable shoring device 26 to shorten. As the overall length shortens, the outer tube 32 b moves downward along the inner tube 32 a, such that the adjustable collar 40 moves toward the stop pin 42. When the beam has deflected the appropriate amount, the lower end of the stop collar 40 contacts the stop pin 42 and limits or substantially precludes any further downward movement of the outer tube 32 b and thus of the beam, such that the beam is held in its optimal, substantially level and horizontal position (as shown in FIG. 7B), while the concrete is placed and cured at the deck surface. The concrete then has a generally uniform thickness over decking material or surface 22.
Preferably, the [0047] gap 41 of the positive stop 43 (i.e. the gap between the adjustable collar 40 and the stop pin 42) is set to the actual amount of camber in the beam and not just an estimated amount. In order to determine the actual amount of camber in the beam, the laser receiver 28 and laser plane generators 30 may be implemented. For example, laser plane generator 30 may be set up at an arbitrary height along one of the columns of the bay. Steel tape, a measuring stick or other measurement device or measuring member or the like (not shown) may then be used to measure the distance from the laser plane 31 generated by the laser plane generator 30 to the bottom of the corrugated metal deck 22 (which is at the same level as the top surfaces 12 d of the beams 12) at each column 18 of the bay 16. Optionally, and preferably, a laser range finder (shown as part of laser receiver 28) may be used to measure the distance from the laser plane 31 generated by the laser plane generator 30 to the bottom of the corrugated metal deck 22 (or top of beam) at each column 18 of the bay 16. An average distance from the laser plane 31 to the bottom of the metal deck 22 (or top of beam) may then be determined by averaging these measurements (the average distance may be manually calculated or may be automatically calculated by pressing an “average” button or the like on the rangefinder or laser receiver, without affecting the scope of the present invention). The laser receiver 28 may then be positioned or zeroed along the adjustable shoring device 26 until it is aligned with the laser plane 31. The laser range finder may then measure the distance from the laser plane 31 to the bottom of the metal deck 22 at each particular adjustable shoring device 26. The difference between the measurements at the column and the measurement at each adjustable shoring device 26 is approximately the camber in the beam at that particular location. The adjustable collar 40 may then be adjusted so that the initial gap 41 between collar 40 and stop pin 42 is at least approximately equal to the measured initial beam camber. A laser receiver 28 may be positioned at each shoring device 26 (as shown in FIG. 1), or a single laser receiver (or more than one laser receiver) may be removably positioned at the shoring device at a fixed or predetermined or designated mounting position at each shoring device and moved from one shoring device to the next while taking a measurement at each shoring device, without affecting the scope of the present invention.
Therefore, the adjustable shoring [0048] device 26 of the present invention provides for a easy and accurate method for measuring the actual initial camber of the beam at the particular location of the shoring device and provides a means for controlling and limiting deflection of the beam, such that the beam does not deflect past the amount of the actual initial camber in the beam. Accordingly, ponding and other problems associated with placing, screeding and curing concrete on an elevated deck surface are substantially reduced. The end result is a deck surface which is flat, smooth and of uniform thickness throughout, without requiring the additional conventional manual labor processes.
Referring now to FIG. 8, a beam or [0049] camber measuring device 50 is operable to measure an amount of camber in a beam via a laser reference plane 31 generated by a laser plane generator (not shown in FIG. 8). The measurement device 50 includes a telescoping rod 52 and a laser receiver 54. The telescoping rod 52 includes an upper hook member 56, which may be placed or hooked over top of an upper surface 12 d of the I-beam 12, as shown in FIG. 8. Telescoping rod 52 includes an inner tube or rod 52 a and an outer tube or rod 52 b and a locking member or collar 58, which is operable to secure the inner tube 52 a relative to outer tube 52 b to lock the overall length of the telescoping rod 52 at a desired length. Laser receiver 54 further includes calipers 54 a or means for measuring a change in location of the laser plane 31 as received by the laser receiver 54, and preferably includes a digital readout 54 b of this difference. Measurement device 50 may further include a level 60 for determining when the telescoping rod 52 is oriented generally vertically, in order to provide a more accurate camber measurement.
During use, [0050] measurement device 50 incorporates the laser plane generator 30 which is operable to generate the laser reference plane 31 at an arbitrary height beneath the beams of the deck. The measurement device 50 is positioned toward an end of a beam and the laser receiver is moved along the outer tube 52 b, or the outer tube 52 b is moved along the inner tube 52 a, until the laser plane 31 is received at a desired location on the laser receiver 54. The laser receiver 54 is then secured in position on the outer tube 52 b and/or the outer tube 52 b is secured relative to the inner tube 52 a, in order to substantially fix the distance between the upper hook 56 and the laser receiver 54. The measurement device 50 may be moved to the ends of other beams and/or girders in the bay, whereby any discrepancy in height between those ends may be averaged to determine an average end height relative to the laser plane. The position of the laser receiver relative to the upper hook member 56 may then be adjusted such that the laser reference plane 31 intercepts or is received by the laser receiver 54 at a desired location corresponding to the average height at the ends of the beams.
Once the average height or average relative position of the upper surface of the ends of the beams to the laser receiver is determined, [0051] measurement device 50 may be positioned toward a mid section or other desired location along a particular beam. The laser plane then intercepts or is received by the laser receiver at a different location, since the generally central region of the cambered beam would be at a higher location than the ends of the beam, due to the initial camber or upward curvature of the beam. The amount of camber or upward curvature of the beam may then be measured due to the change in location of the laser plane 31 on the laser receiver 54. This may be read via the digital readout 54 b at laser receiver 54, and provides a measurement of the actual camber of the beam at each desired location along the beam. This process may be repeated for other locations along the beam and for other beams of the particular bay.
Once the amount of camber at a particular location along the beam is determined, an appropriate shoring device may be positioned there to limit movement or deflection of the beam at an amount generally equivalent to its initial camber. The appropriate shoring device may be an adjustable shoring device, such as adjustable shoring [0052] device 26, discussed above, or may be a conventional shoring column cut or otherwise formed to the desired length, without affecting the scope of the present invention. It is further envisioned that an adjustable shoring attachment may be connected to an existing shoring column to provide for adjustability of the shoring column and to allow for the appropriate amount of deflection of the beam, as discussed below with respect to FIGS. 9-12, without affecting the scope of the present invention.
Referring now to FIGS. [0053] 9-12, an adjustable shoring attachment 70 may be positioned at a lower end 72 a or an upper end 72 b of an existing shoring column 72 and may be adjustable to allow for the appropriate amount of deflection of the beam at its particular location. Adjustable shoring attachment is spring loaded or otherwise biased to allow for easy implementation of the shoring column without the brackets and supports previously required to hold the shoring column in position prior to placing the concrete. Adjustable shoring attachment 70 includes a telescoping tube section 74, which further includes an inner tube section 74 a and an outer tube section 74 b which slidably engage one another to adjust the overall length of the tube section 74 and thus of the adjustable shoring attachment 70. A compression spring 76 or other biasing member is positioned within the tube sections 74 a, 74 b, in order to bias the attachment 70 toward its extended position. Inner tube 74 a includes and inner stop 75 a and is slidable within outer tube 74 b, which further includes an outer stop 75 b at its lower or receiving end. The inner and outer stops 75 a, 75 b prevent over extension and unintentional disassembly of the tube section 74 when transporting the adjustable attachment 70 and setting up the adjustable attachment 70 at an appropriate location. As shown in FIG. 9, a spacer sleeve 77 is preferably positioned within outer tube 74 b and around inner tube 74 a, and functions to contact outer stop 75 b and inner stop 75 a to limit extension of tube section 74. This ensures that, even at full extension of tube section 74, the outer and inner tubes overlap a sufficient amount to prevent bending or binding of the tubes as they are loaded.
[0054] Adjustable attachment 70 further includes a pair of base plates 78 a, 78 b, which are positioned at opposite ends of the tube section 74 for engaging the existing shoring column 72 at one end and the support surface 20 or lower surface 12 c of the beam 12 at the other end of the adjustable attachment 70. For example, as shown in FIGS. 9, 10A, 10B and 12, lower base plate 78 a engages support surface 20, while upper base plate 78 b engages a lower end 72 a of the existing shoring column 72. Alternately, as shown in FIGS. 1A and 1B, adjustable attachment 70 may be positioned at an upper end 72 b of shoring column 72, such that lower base plate 78 a engages upper end 72 b of shoring column 72, while upper base plate 78 b engages a lower surface of the beam 12. As shown in FIG. 9, a weld joint 78 c may occur at the junction of base plate 78 a and inner tube 74 a. In such a situation, a stop collar 79 may be positioned around the weld joint 78 c at base plate 78 a to provide a flat upper surface for outer stop 75 b to engage when the beam has deflected the desired amount, as discussed below. The stop collar 79 preferably includes a beveled edge to fit around the weld joint, such that the lower surface of the stop collar 79 engages the flat upper surface of the base plate 78 a.
Similar to the tube sections of adjustable shoring [0055] device 26, the tube sections of the adjustable attachment 70 may be square or circular in cross section or may be other shapes as desired, without affecting the scope of the present invention. As shown in FIGS. 9-12, both the inner and outer tube sections are hollow to allow the biasing member or compression spring to extend the entire length of the adjustable attachment to engage the opposed surfaces of the base plates. However, a spring stop pin or plate or the like may be provided at the outer tube and/or the inner tube to engage an end of a shorter spring, without affecting the scope of the present invention.
After the amount of camber at the particular location for the shoring [0056] column 72 and adjustable attachment 70 is determined, such as via the measuring methods discussed above with respect to measuring device 50, the shoring column 72 may be adjusted in length via conventional methods, such as via cutting or forming the shoring column to the desired length or via known pin and threaded collar adjustment means. The length of shoring column 72 is adjusted such that when the adjustable attachment 70 is positioned at an end of the shoring column 72, the distance between outer stop 75 b and stop collar 79 at base plate 78 a (and/or the distance between inner stop 75 a and base plate 78 b) is approximately equal to the amount of initial camber in the beam at that position (shown as a gap 81 in FIG. 9). The compression spring 76 then functions to bias the adjustable attachment 70 toward its extended position, in order to press the shoring column upward against the beam (or downward against the floor, depending on where adjustable attachment 70 is positioned) to hold the shoring column 72 and extendable attachment 70 in position between the beam 12 and support surface 20 prior to placing concrete at the deck 22 above the beam 12 (as shown in FIGS. 10A and 11A). As concrete is placed on the deck surface 22 above beam 12, the beam deflects downward and compresses the compression spring 76 as outer stop 75 b moves toward stop collar 79 at base plate 78 a and/or inner stop 75 a moves toward base plate 78 b. When the appropriate amount of deflection has occurred in the beam 12, outer stop 75 b and/or inner stop 75 a contacts stop collar 79 and/or base plate 78 b, respectively, and prevents further compression of the tubes 74, and thus substantially precludes or limits further downward deflection of the beam 12, whereby the beam is then positioned in its substantially horizontal and level orientation for further placing, smoothing and/or curing of concrete on the deck surface above the beams (as shown in FIGS. 10B and 11B).
Referring now to FIG. 12, the [0057] adjustable attachment 70 may optionally include a monitoring device 80 to assist with setting the travel dimension (shown at 83 in FIG. 12) and for monitoring progress in the amount of deflection of the beam as the concrete is placed on the deck surface above the beam. In the illustrated embodiment, the monitoring device 80 includes a graduated measuring rod 81 and indicator 82. The measuring rod 81 is fixedly mounted to base plate 78 a and extends upwardly therefrom and through a passageway or guide 78 d in the opposite base plate 78 b. A stop collar 84 may be positioned along measuring rod 81 to indicate the point at which deflection of the beam will stop due to the outer or inner stop contacting the opposite base plate and thus limiting or precluding any further deflection of the beam. Measuring rod 81 may further include a scale or indicator 81 a along an upper portion of measuring rod 81, whereby an indicating point or needle 82 a of indicator 82 functions to indicate the amount of deflection of the beam or movement of base plate 78 b while concrete is placed and cured on the deck surface above the beam. Placing of the concrete may then be adjusted in response to the amount of deflection occurring while the concrete is being placed, since that amount of deflection may be accurately monitored via monitoring device 80.
Referring now to FIG. 13, a mid-mount adjustable shoring [0058] attachment 90 is shown mounted at or near a middle region of an existing shoring post 92. Similar to adjustable attachment 70, mid-mount adjustable attachment 90 includes a telescoping tube section 94 having an inner tube section 94 a and an outer tube section 94 b. A compression spring 96 is positioned within tube section 94 and between a pair of base plates 98 a, 98 b.
The existing shoring [0059] post 92 is preferably a telescoping shoring post and includes an inner post section 92 a and an outer post section 92 b. The inner post section 92 a extends through the mid-mount spring attachment 90 and into the outer tube section 92 b at the opposite end of the attachment 90. The existing shoring post further includes an adjustment collar 100 and post plate 102 for adjusting the overall length of the shoring post 92. Once the amount of camber at the desired location along the beam is known, such as via measurement of the camber via the above discussed means, the length of the shoring post may be adjusted such that the gap 91 between plate 98 b and an end 94 c of outer tube section 94 b of adjustable attachment 90 and/or between plate 98 a and an end 94 d of inner tube section 94 a, is substantially equal to the amount of camber in the beam at that location. The amount of compression of the adjustable attachment and thus the amount of deflection of the beam is thus limited to at least approximately the amount of camber in the beam, since further deflection will be limited or precluded via engagement of the ends 94 c, 94 d with plates 98 b, 98 a, respectively. It is further envisioned that inner tube 94 a may further include a monitoring device or a visible scale on its outer surface 94 e for monitoring the amount of deflection as the concrete is placed at the deck surface above the beam or beams.
Therefore, the present invention provides a means for measuring the actual amount of camber in a beam via laser plane generating devices and further provides a means for limiting deflection of the beam to an amount substantially equal to the measured camber. The present invention further provides for an adjustable shoring system which may be easily placed at the desired location beneath the beam and which is easily held in place beneath the beam via a biasing member exerting a force at the lower surface of the beam. The shoring system is thus positioned at, and maintained at, its desired location beneath the beam without requiring any additional bracketry or mounting devices to secure it in position. Also, the present invention provides for a means for easily monitoring and adjusting the amount of deflection for the particular location along the beam. The present invention further provides for an adjustable attachment which is adaptable for use with existing shoring posts and which again allows for easy positioning of the shoring posts at the desired location and limiting of deflection of the beam to a desired, predetermined amount. The desired amount of deflection is substantially equal to the initial camber in the beam, which may be an estimated value, design specification of the beam, or a measured value, such as via any of the measuring means in accordance with the present invention. [0060]
Changes and modifications in the specifically described embodiments may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims as interpreted according to the principles of patent law. [0061]

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A measuring system for measuring an initial camber in a beam, said measuring system comprising:

a laser reference generator operable to generate a laser reference;

a laser receiver operable to receive said laser reference; and

a support member, said laser receiver being positionable on said support member, said support member having an end adapted to removably mount to a portion of the beam, said laser receiver being positioned on said support member to receive said laser reference at a first location when said support member is positioned at an end portion of a beam, said laser receiver being operable to receive said laser reference at a second location when said support member is positioned at a generally central portion of the beam, a vertical distance between said first and second locations defining the initial camber in the beam.

2. The measuring system of claim 1, wherein said end of said support member is adapted to removably mount to an upper surface of the beam, said support member hanging downward from the upper surface of the beam.

3. The measuring system of claim 1, wherein said support member comprises an adjustable support member which is adjustable in length to adjust a position of said laser receiver relative to said end of said support member.

4. The measuring system of claim 1, wherein said laser receiver is adjustably positioned on said support member and is adjustable relative to said end of said support member to position said laser receiver to receive said laser reference at said first location.

5. The measuring system of claim 1 including a leveling device on said support member for indicating when said support member is positioned generally vertical.

6. The measuring system of claim 1, wherein said first location comprises an average location of at least two first locations when said support member is mounted at at least two end portions.

7. A method for measuring an initial camber of a beam supported at opposite ends, said method comprising:

generating a laser reference at a preset level;

comparing a first distance between an end portion of the beam and said preset level with a second distance between a generally central portion of the beam and said preset level; and

determining an initial camber of the beam at said generally central portion by determining a difference between said first and second distances.

8. The method of claim 7 including:

positioning a laser receiver at a support member;

positioning said support member at an end portion of the beam;

receiving said laser reference at a first receiving location on said laser receiver when said support member is positioned at an end portion of the beam, said first distance being defined between the end portion of the beam and said first receiving location on said laser receiver.

9. The method of claim 8 including adjusting one of said laser reference and said laser receiver relative to the end of the beam and receiving said laser reference at said first location on said laser receiver.

10. The method of claim 8 including:

positioning said support member at a generally central portion of the beam; and

receiving said laser reference at a second receiving location on said laser receiver when said support member is positioned at the generally central portion of the beam, said second distance being defined between the generally central portion of the beam and said second receiving location on said laser receiver.

11. The method of claim 10, wherein determining a difference between said first and second distances comprises determining a vertical distance between said first and second locations on said laser receiver.

12. The method of claim 10, wherein positioning said support member at the beam comprises positioning an end portion of said support member at the beam, whereby said support member hangs downward from the beam.

13. The method of claim 10 including adjustably positioning said laser receiver along said support member relative to said end portion of said support member to receive said laser reference.

14. The method of claim 10 including adjusting a length of said support member to adjust a position of said laser receiver relative to said end portion of said support member to receive said laser reference.

15. The method of claim 10 including leveling a portion of said support member with a leveling device on said support member to position said support member in a generally vertical orientation.

16. The method of claim 8, wherein receiving said laser reference at a first location comprises receiving said laser reference at multiple first locations by attaching said support member to at least two end portions of at least one beam.

17. The method of claim 16 including averaging said multiple first locations to determine an average first location and measuring the difference between said average first location and said second location.

18. The method of claim 7 including:

positioning a measuring device at a support member;

positioning said support member at an end portion of the beam;

receiving said laser reference at a first receiving location on said measuring device when said support member is positioned at an end portion of the beam, said first distance being defined between the end portion of the beam and said first receiving location on said measuring device.

19. The method of claim 18, wherein receiving said laser reference at a first location comprises receiving said laser reference at multiple first locations by attaching said support member to at least two end portions of at least one beam.

20. The method of claim 19 including averaging said multiple first locations to determine an average first location and measuring the difference between said average first location and said second location.

21. The method of claim 7 including supporting the generally central portion of the beam to limit deflection of the beam beyond a predetermined amount while the beam is loaded.

22. The method of claim 21, wherein said predetermined amount is approximately equal to said difference between said first and second distances.

23. The method of claim 22 including:

providing an adjustable support device comprising an adjustable support section, a biasing member for biasing said support section toward an extended position and a positive stop member;

positioning said adjustable shoring device at the generally central portion of a beam and between a lower surface of the beam and the support surface, said biasing member extending said support section to retain said support section between the lower surface of the beam and the support surface; and

setting an initial gap of said positive stop member to be approximately equal to said predetermined amount.

24. The method of claim 23 including:

placing uncured concrete on the beams while said adjustable support device is positioned at the generally central portion of the beam; and

limiting downward deflection of the beam with said positive stop member when the beam has deflected said predetermined amount in response to the placing of the uncured concrete.

25. The method of claim 24 including removing said adjustable support device from the generally central portion of the beam after the placed concrete has at least partially cured.

26. An adjustable shoring device which is adjustable in length and positionable between a generally central portion of a beam and a support surface below the beam, said adjustable shoring device being configured to limit downward deflection of the beam to a predetermined amount while the beam is loaded, said adjustable shoring device comprising:

a telescoping support section which is extendable and compressible to adjust an overall length of said support section, said support section being positionable at a generally central portion of a beam and between a lower surface of the beam and the support surface;

a biasing member for biasing said support section toward an extended position, said biasing member biasing said support section toward said extended position to generally removably secure said support section in place between the lower surface of the beam and the support surface, said biasing member being compressible to allow compression of said support section toward a compressed position; and

a positive stop to limit compression of said support section, said positive stop defining an initial gap, said support section, said biasing member and said initial gap being compressible in response to downward deflection of the beam, said positive stop limiting compression of said support section when said initial gap is closed.

27. The adjustable shoring device of claim 26, wherein said support section is adapted to engage the lower surface of the beam at one end and the support surface at the other end.

28. The adjustable shoring device of claim 26, wherein said support section is adapted to engage a shore member at one end and one of the beam or the support surface at the other end.

29. The adjustable shoring device of claim 26, wherein said support section is adapted to be attached in a middle portion of an adjustable shore member.

30. The adjustable shoring device of claim 26, wherein said positive stop comprises a collar and a stop member, said positive stop limiting compression of said support section when said collar engages said stop member.

31. The adjustable shoring device of claim 30, wherein said collar comprises an adjustable collar which is adjustable along said support section to adjust said initial gap, said initial gap being defined between said stop member and said collar.

32. The adjustable shoring device of claim 26 including a monitoring device positioned along said support section, said monitoring device being operable to monitor an amount of compression of said support section as concrete is placed on the beam.

33. The adjustable shoring device of claim 26, wherein said support section comprises a telescoping support section comprising an outer member and an inner member, said outer member receiving said inner member at a receiving end of said outer member.

34. The adjustable shoring device of claim 33, wherein said positive stop comprises an adjustable stop collar at said receiving end of said outer member and a stop member on said inner member, said initial gap being defined between said stop member and said stop collar.

35. The adjustable shoring device of claim 26 including a laser receiver positioned at said support section, said laser receiver being operable to receive a laser reference at a preset level.

36. The adjustable shoring device of claim 35, wherein said positive stop is adjustable to adjust said initial gap in response to a comparison between a first distance between an end portion of the beam and said preset level and a second distance between the generally central portion of the beam and said preset level.