AU2651792A - Adjustable concrete formwork system - Google Patents

Description

ADJUSTABLE CONCRETE FORMWORK SYSTEM

FIELD OF THE INVENTION

This invention pertains to a novel adjustable concrete formwork system which can be used in the manufacture of a wide range of cross-sectional shaped concrete structures.

SUMMARY OF THE INVENTION

The invention is directed to a cast-in-place or precast concrete form comprising: (a) at least one first member, with a web located on a first side of the first member; (b) at least one second member, with a second web located on the first side of the second member; and (c) at least one connecting member connecting telescopically the respective first member, with the respective second member, said telescoping connecting member enabling the first and second members to be moved relative to one another.

An elongated strip can be positioned between the two webs. The first and second webs can be planar and positioned one above the other. The lower portion of the upper web, and the upper portion of the lower web, together can protrude away from the first and second members to form a common protrusion. The first member can be elevated relative to the second member. A web can extend between the protruding upper and lower webs.

At least two first members can be spatially arranged relative to one another with at least two second spatially arranged members. A strip can extend from the top of the first upper member to the top of the other upper member, and a second strip can extend from the bottom of the lower member to the bottom of the other lower member.

The concrete form can have one or more walers replace the first member or the second member. The length of the connecting member can be varied. The first member or the second member or the connecting member can be eliminated in certain configurations.

The form can be arranged in parallel and opposed to a second concrete form of the same or a different configuration, the upper and lower webs facing one another to define a cavity in which concrete can be poured to form a concrete beam having a rectangular cross-section, an "I" cross-section, a "T" cross-section, a "J" cross-section, a "C" cross-section, an "L" cross-section, or a corrugated cross-section. The pair of opposed forms can be held together by snap-ties.

DRAWINGS

Figure 1 illustrates an end view of a conventional timber formwork system comprising timber, walers, snap ties and keeper wedges, for constructing a concrete beam of rectangular cross-section.

Figure 2 illustrates an end view of a conventional timber formwork system for constructing a rectangular cross-section poured-in-place concrete beam of higher elevation than the one illustrated in Figure 1.

Figure 3 illustrates an end view of an alternative conventional timber formwork system for constructing a poured in place concrete beam of rectangular cross-section.

Figure 4 illustrates an end view of an alternative conventional timber formwork system for constructing a rectangular cross-section poured-in-place concrete beam of higher elevation than the one illustrated in Figure 3.

Figure 5 illustrates an end view of an adjustable height embodiment of the formwork system for pouring in place a rectangular cross-section concrete beam.

Figure 6 illustrates an end view of an embodiment of the formwork system utilized for pouring in place a concrete beam having a "C" cross-section.

Figure 7 illustrates an end view of an embodiment of the adjustable formwork system, in extended orientation, for pouring in place a concrete beam of rectangular cross-section of greater height than the beam that is obtained by using the form illustrated in Figure 5. Figure 8 illustrates an end view of a pair of extended height concrete forms assembled together with snap ties and keeper plates.

Figure 9 illustrates an end view of an embodiment of an extended height formwork, with assembled snap ties and keeper plates, and at the right, in exploded view, an extended height form, with an extended slider plate, the combination being adapted to produce a cast-in-place concrete beam having an extended height "C" cross-section.

Figue 10 illustrates an end view an assembled pair of extended height concrete forms adapted to form a cast-in-place concrete beam having a "C" cross-section shape.

Figure 11 illustrates an end view of an assembled extended height formwork system adapted to form a cast-in-place concrete beam having an "I" cross-section.

Figure 12 illustrates a side view of an extended height form with the lower sleeve and slider and installed keeper plate.

Figures 13(a) and 13(b) illustrate respectively a top section and a side view of the extension slider for the adjustable height formwork system.

Figure 14 illustrates a side, partial section view of the adjustable height form showing the bottom of the extension slider being adapted to fit with the snap-tie receiving tube.

Figure 15 illustrates a detail end section view of the lower portion of an adjustable form showing internal reinforcements and snap-tie guide tube.

Figure 16 illustrates an end section view of the lower portion of the adjustable form, with panel end gusset stiffener.

Figure 17 illustrates an end partial section view of the mid-section of the extended height form, showing the extension slider, the plywood face, and mid-elevation securing snap-tie and keeper plate. Figure 18 illustrates an end section view of the lower portion of an extended height form illustrating the extension slider, the snap-tie and receiving tube, and the protruding inner face, adapted to form a recess in the poured-in-place concrete beam.

Figure 19 illustrates an end partial section view of the mid-portion of the adjustable form illustrated in Figure 18, showing mid-section securing snap-tie, and reinforcing timber spacer.

Figure 20 illustrates an embodiment of the adjustable form with sliders on the right side adapted to form a concrete beam with an inverted "J" cross-section.

Figure 21 illustrates an embodiment of the adjustable form with sliders on the right side adapted to form a concrete beam with an inverted "T" cross-section.

Figure 22 illustrates an embodiment of the adjustable form with sliders on the right side adapted to form a concrete beam with an inverted "L" cross-section.

Figure 23 illustrates an end view of an embodiment of an adjustable form adapted to form a concrete beam with a "C" cross-section beam alternative to Figures 6, 9 and 10.

Figure 23a illustrates an end view of a "C" cross-section concrete beam formed by the form illustrated in Figure 23.

Figure 24 illustrates an end view of an embodiment of an adjustable form adapted to form a rectangular cross-section beam alternative to Figures 5, 7 and 8.

Figure 24a illustrates an end view of a concrete beam with a rectangular cross-section formed by the form illustrated in Figure 24.

Figure 25 illustrates an end view of an embodiment of an adjustable form adapted to form an "L" cross-section beam alternative to Figure 22.

Figure 25a illustrates an end view of concrete beam with a "J" shaped cross-section formed by the form illustrated in Figure 25. Figure 26 illustrates an end view of an embodiment of an adjustable form adapted to form a rectangular cross-section beam alternative to Figure 24.

Figure 26a illustrates an end view of a concrete beam with a rectangular cross-section formed by the form illustrated in Figure 26.

Figure 27 illustrates an end view of an embodiment of an adjustable form adapted to form a rectangular cross-section beam alternative to Figure 24.

Figure 27a illustrates an end view of a concrete beam with a rectangular cross-section.

Figure 28 illustrates an end view of an embodiment of an adjustable form adapted to form a rectangular cross-section beam alternative to Figures 24, 26 or 27.

Figure 28a illustrates an end view of a concrete beam with a rectangular cross-section formed by the form illustrated in Figure 28.

Figure 29 illustrates an end view of an embodiment of an adjustable form adapted to form an inverted "T" cross-section beam alternative to Figure 21.

Figure 29a illustrates an end view of a concrete beam with an inverted "T" cross-section, formed by the form illustrated in Figure 29.

Figure 30 illustrates an end view of an embodiment of an adjustable form adapted to form an inverted "J" cross-section beam alternative to Figure 20.

Figure 30a illustrates an end view of a concrete beam with an inverted "J" cross-section formed by the form illustrated in Figure 30.

Figure 31 illustrates an end view of a concrete form to produce a concrete beam with a double sided corrugate shape.

Figure 31a illustrates an end view of a concrete beam with a double-sided corrugated shape formed by the form illustrated in Figure 31. Figure 32 illustrates an end view of an embodiment of form which produces a concrete beam with a corrugated exterior.

Figure 32a illustrates an end view of a concrete beam with a corrugated exterior surface formed by the form illustrated in Figure 32.

Figures 33, 33a, 34 and 34a illustrate end views of forms and beams with undulating cross-sections.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

Figure 1 illustrates an end view of a conventional timber formwork system comprising timber, walers, snap ties and wedges, used to form a cast-in-place concrete beam of rectangular cross-section.

Figure 2 illustrates an end view of a timber formwork system for constructing a poured-in-place concrete beam of higher elevation than the one illustrated in Figure 1. This formwork system resembles the one shown in Figure 24 except that three snap-ties are required, and accompanying walers 58 and wedges 56 are required. The form is labour intensive .because it involves a considerable amount of manual labour to cut the various wooden pieces to size. A number of separate pieces are required for a form of this construction. The wood form comprises a pair of cut-to-size facing plywood sheets 50, reinforced by bracing 2 X 4's 52, which are held by lower and upper snap-ties 54, which are of conventional construction. The snap-ties 54 extend through the plywood faces 50, and are secured by wedges 56, which are hammer driven into place by the form installer. The wedges 56 are braced against a pair of walers 58 which are positioned on the top and bottom sides of the respective snap-ties 54, the wedges 56 holding the pair of walers 58 against the rear faces of the 2 X 4 bracing 52.

Figure 3 illustrates an alternative embodiment of a conventional wooden form used for casting in place a rectangular cross-section concrete beam in place. This formwork system is generally cheaper than the one illustrated in Figures 1 and 2, because fewer pieces of timber are required. The use of a second waler 58 for each snap-tie 54 is eliminated with this type of form construction. However, more specific shapes of metal pieces are required. For instance, a metal piece 60, which is accompanied by one waler 58, is used in association with each wedge 56, and snap-tie 54. In this orientation, the 2 X 4 bracing 52 is positioned on the outside of the waler 58, removed from the plywood face 50. The 2 X 4 bracing 52 is secured to the waler 58 by a specially constructed fastener 62, with locking handle 64.

Figure 4 illustrates an end view of a conventional formwork construction similar to that shown in Figure 3, except in this case, the form is adapted for casting in place a concrete beam of heightened elevation rectangular cross-section. The conventional embodiment shown in Figure 4 uses three sets of snap-ties and three diffeent elevations.

Figure 5 illustrates an end view of an adjustable height embodiment of the applicant's form adapted for pouring in place a rectangular cross-section concrete beam. This embodiment has the advantage that it can be lowered or raised in height to form cast-in-place concrete beams of specified heights. In the orientation illustrated in Figure 5, the upper sleeve 70 and the lower sleeve 72 are in compressed (low elevation) configuration. This configuration is used to pour in place a concrete beam of rectangular cross-section of a conventional height of about 16 to 20 inches (40 to 50 cm). The upper sleeve 70 and the lower sleeve 72, of the pair of forms, are held together by a pair of snap-ties 74. An upper nail strip 78 formed of wood is secured on the top of upper sleeve 70. A lower wooden nail strip 80 is secured to the bottom face of lower sleeve 72. A plywood strip 76 seals the space between the upper planar face 84, which is typically formed of steel plate, and lower planar face 86, which is also typically formed of steel plate. Upper face 84 and lower face 86 are reinforced by respective reinforcing braces 88. The left and right forms are held in place by a pair of snap-ties 74, which are secured at their respective ends by keeper plates 82.

Figure 6 illustrates an alternative embodiment of the applicant's adjustable form system as utilized for pouring in place a concrete beam having a "C" cross-section. In the version shown in Figure 6, the right side form has upper and lower faces 90 and 92, which are bent to protrude inwardly in the direction of the opposite form 84 and 86. The horizontal distance between the sleeve 70 and the protruding face is termed the offset and determines the degree of indentation in the concrete beam having a "C" cross-section. Except for the protruding faces 90 and 92, the basic construction of the form is similar to that described for Figure 5.

Figure 7 illustrates a pair of facing forms, similar to that shown in Figure 5, except that the forms are in an extended configuration, which enables a beam of higher elevation to be poured. As seen in Figure 7, upper sleeve 70 has been raised on slider 98, to provide an extended elevation. Upper sleeve 70 is telescopically arranged with slider 98, in combination with lower sleeve 72. In the lower elevation position, as illustrated in Figure 5, slider 98 is not visible. However, in the elevated orientation, upper sleeve 70 and lower sleeve 72 are drawn apart in telescopic fashion so as to expose slider 98. As seen in Figure 7, a longer infill panel 94 is required to fit the space generated by exposing slider

98. Infill panel 94 is normally constructed of plywood, cut to size. Upper sleeve 70 is an inverted version of lower sleeve 72. Likewise, upper nail strip 78 is an inverted version of lower nail strip 80. Figure 7 also illustrates the two planar lateral sections 102, which fit on the concrete-facing side of the form, over upper sleeve 70 and lower sleeve 72 respectively. Lateral sections 102 are normally formed of sheet steel. Slider 98 is normally formed of aluminum. The lateral sections 102 are adapted to grip strip 78 at the top and infill panel 94 at the bottom. Lower section 102 is an inverted version of the upper lateral section. Upper sleeve 70 and lower sleeve 72 are normally formed of steel.

Figure 8 shows a facing pair of extended height forms, of the same design as shown in Figure 7, completely assembled. Portions of the form are shown in partial section view. In Figure 8, keeper plates 82 have been secured to snap-ties 74, extending through three positions on the upper sleeve 70, infill panel 94, and lower sleeve 72 respectively. Figure 8 illustrates reinforcing braces 88, which support the upper and lower lateral sections 102, and prevent them from bending outwardly from hydrostatic pressure generated by the poured-in-place concrete.

The form illustrated in Figure 8 is set up for forming a poured-in-place concrete beam of elevated rectangular cross-section. Once the concrete has been poured in place, has been vibrated and has set, then the exterior ends of the conventional snap-ties, which are in the form of hexagonal bolt heads, are twisted, which break the snapties adjacent the inner faces of the facing forms. The forms can then be readily removed, leaving the mid-regions of the snap-ties 74 in place in the interior of the poured-in-place concrete. The removed forms can then be used again at a new location for pouring another concrete beam of elevated rectangular cross-section.

In the design illustrated in Figures 7 and 8, all pieces are of standard size. The only piece of variable size is the plywood infill panel 94. Upper sleeve 70 is an inverted form of lower sleeve 72. Upper lateral section 102 is an inverted form of lower lateral section 102. Upper nail strip 78 is an inverted form of lower nail strip 80. Normally, infill panel 94 is constructed of 5-ply plywood, upper nail strip 78 and lower nail strip 80 are formed in a planing mill of suitable wood, such as spruce, pine, fir, or the like, upper sleeve 70 and lower sleeve 72 and lateral sections 102 are formed of steel, and slider 98 is formed of extruded aluminum.

Figure 9 illustrates an end view (the right form is shown in exploded end view) of a pair of concrete forms according to the invention, in extended elevation position. The combination of two forms illustrated in Figure 9 produce a poured-in-place concrete beam having a "C" cross-section shape. The form shown at the left is similar to that shown previously in Figures 7 and 8. However, the form shown at the right in Figure 8 has a pair of inwardly projecting lateral sections 104. The inwardly projecting "offset" distance of lateral sections 104 corresponds with the lateral dimension of reinforcing waler 96. Normally, waler 96 would be constructed of a standard 2 X 4 timber piece, which in reality measures 3-1/2 inches (9 cm). Thus, it is not necessary to cut the waler 96 to an unusual size. Waler 96 is required for reinforcing infill panel 94, so that it does not bend under hydrostatic pressure of the freshly cast concrete. Except for the pair of protruding lateral sections 104, and waler 96, other components of the form shown on the right side of Figure 9 are the same as those for the form shown on the left side of Figure 9. Figure 9 shows the construction of the keeper plate 82. The keeper plate has a key-hole in it. The keeper plate 82, by using the round portion of the hole, is placed over the end of the snap-tie 74, and is then hammered down to force the snap-tie head into the narrower section of the hole.

Figure 10 illustrates an end partial section view of the pair of forms illustrated in Figure 9, in assembled position. A cast-in-place concrete beam, formed by the combination of forms illustrated in Figure 10, has a "C" extended elevation cross-sectional shape. As illustrated in Figure 10, reinforcing waler 96 rests on the middle snap-tie 74. No separate support is therefore required in order to hold waler 96 in position. Figure 11 illustrates in end view a configuration of a pair of adjustable forms adapted to cast a concrete beam having an "I" cross-section. This "I" cross-sectional shape of beam has the advantage that less concrete is used, but greater strength is in effect acquired, as illustrated by the data in Table 3 below. In the orientation illustrated in Figure 11, two forms constructed to have upper and lower inwardly facing protruding lateral sections 104, are utilized.

Figure 12 illustrates a side view of the adjustable form illustrated in Figure 7. As illustrated in Figure 12, slider 98 extends downwardly into lower sleeve 72. Lateral section 102 extends to either side of. lower sleeve 72. Lower nail strip 80 is secured to the bottom portion of lateral section 102. Figure 12 also illustrates keeper plate 82, which is fitted over the end by snap-tie 74, to secure entire assembly. While not visible in Figure 11, there is a guide tube in lower sleeve 72 through which snap-tie 7 is threaded. This guide tube is advantageous because it prevents the installer from wasting time endeavouring to thread snap-tie 74 through lower sleeve 72. Figure 12 illustrates a spacer 112 of square cross-sectional area to secure slider components 98 such that the snap-tie end can pass between.

Figures 13(a) and 13(b) illustrate top-section and side-section views of a slider 98, which is constructed of a combination of aluminum sheet metal and timber. The timber acts as reinforcement and is useful for enabling the installer to drive in securing nails at convenient locations. Securing bolt 118 is visible in Figure 13(b). Slider 98 extends into the interior of lower sleeve 72, which is typically formed of steel sheet metal. Timber pieces 114 and 116 can be constructed of conventional 2 X 4's (5 - 10 cm). Securing bolts 118 can be placed at various elevations along the slider 98.

Figure 14 illustrates a side, partial section view of the form, illustrating in particular the construc tion of the lower end 120 of slider 98. The lower end of slider 98 is adapted so that it fits over and does not interfere with guide tube 110. It will be understood that other designs can be used so that there is no interference between the base of slider 98 and guide tube 110.

Figure 15 illustrates an end section view of the construction of the lower sleeve 72 with a snap-tie 74 held in place by a keeper plate 82. Reinforcing braces 88 are visible. Also, guide tube 110 is shown. The slider 98 slides up and down within the interior of lower sleeve 72.

Figure 16 illustrates an end view of a form construction similar to that shown in Figure 15. However, as seen in Figure 16, an optional reinforcing gusset piece

100 is installed behind lower lateral section 102. Gusset piece 102 is optional and stiffens the face of lateral section 102, thereby preventing lateral section 102 from assuming a concave configuration due to hydrostatic pressure of the freshly cast concrete.

Figure 17 illustrates a detailed end view of the mid-region of the adjustable form in extended configuration. Slider 98 is secured in combination with infill panel 94 and lower sleeve 72 and lateral section 102 by a mid elevation snap-tie 74, held in place by a keeper plate 82 on the rear face of the slider 98.

Figure 18 shows a detailed end partial section view of the lower region of a form with an inwardly protruding lateral section 104. This form design is used to produce a concrete beam having either a "C" cross-section, an "I" cross-section, a "T" cross-section or a "J" cross-section. The lower sleeve 72, as seen in Figure 18, is fitted with an inwardly protruding lateral section piece 104. Infill panel 94 is fitted into the top portion of lateral section 104. The protrusion of lateral section 104 is strengthened by a stiffener 122, which enables the protrusion to withstand the lateral hydrostatic forces of the freshly cast concrete. Figure 19 illustrates a detailed side partial section view of the mid-region of the form configuration utilized for producing a concrete beam of "C", "I", "T" or "J" cross-section. Supporting waler 96, as discussed previously, is visible in Figure 19. Waler 96 rests on snap-tie 74 and prevents infill panel 94 from being pushed outwardly by the weight of the freshly cast concrete. Stiffener 122 is also visible in Figure 19. The offset distance, that is, the distance that infill panel 94 projects inwardly (to the left) in relation to slider 98, is specified usually to be that of a standard "2 X 4" timber. In this way, conventional commercially available pieces of lumber can be used in combination with the form system of the invention. Typically, stiffener 122, and lower sleeve 72, are formed of steel sheet. Slider 98 is typically formed of extruded aluminum, which assists in the sliding action that can take place between slider 98, rubbing against the interior surface of lower sleeve 72.

Figure 20 illustrates an embodiment of the adjustable form with an offset slider on the right side adapted to form a concrete beam with an inverted "J" cross-section. Figure 21 illustrates an embodiment of the adjustable form offset with sliders on both the right and left sides adapted to form a concrete beam with an inverted "T" cross-section, and Figure 22 illustrates an embodiment of the adjustable form with an offset slider on the right side adapted to form a concrete beam with an inverted "L" cross-section.

The configurations illustrated in Figures 20, 21 and 22 are possible by combining selected combinations of lower sleeves, sliders and upper sleeves. In certain configurations, spacers 124 must be inserted in order to hold one slider 98 in proper orientation with adjoining slider 98. The advantage is that the basic adjustable form design can be used to form various cross-sectional shapes of concrete beams. In the configurations shown in Figures 20, 21 and 22, the beams can be cast directly on the ground, thereby eliminating the need to pour footings, before pouring the grade beam.

Example and Tables

The following is an analysis of the amount of concrete that is required in order to pour a conventional concrete beam or column, of the various shapes shown and disclosed herein, utilizing the two-sided beam formwork system. Columns can be constructed by utilizing four-sided forms.

The most significant single feature of the formwork system is ease and simplicity of set up and removal. The panel design provides an efficient combination of superior strength and precision of dimensionally accurate steel fabricated sections together with the economy and versatility of timber construction.

In addition to being a significantly more cost effective method of casting conventional rectangular (Figure 5), square (Table 2) or elongated rectangular sections (Figure 8), the system readily lends itself to forming any one of five beam and column section shapes, all of which are more structurally efficient (equal to or greater design strength with less material), while actually decreasing formwork costs and increasing production levels.

The following two Tables (Tables 1 and 2) show section properties for various beam and column section shapes as well as significant material and weight efficiencies associated with each section shape in comparison to a conventional 8 inch by 24 inch (20 by 60 cm) rectangular beam section shape (Figure 5), and a conventional 24 inch by 24 inch (60 by 60 cm) square column section shape (Table 2).

Economies associated with material and structural efficiencies as shown in Tables 1 and 2 apply only to the smallest size range of beam and column sections. Material and structural efficiencies and associated cost savings increase in a manner directly proportional to any dimen sional increase from the conventional 8 inch by 24 inch (20 by 60 cm) rectangular light beam section (Figure 5) as shown in Table 1, or the conventional 24 inch by 24 inch (60 by 60 cm) square column section as shown in Table 2.

In Table 1, Beam Types of various cross-sectional shapes with a 2 inch (5 cm) offset have been identified as follows:

B-1 = rectangular shape shown in Figure 5;

B-2 = I-cross-section shape shown in Figure 11; B-3 = C-cross-section shape shown in Figure 6;

B-4 = inverted T-cross-section shape shown in Figure 21;

B-5 = L-cross-section shape shown in Figure 22;

B-6 = inverted J-cross-section shape shown in Figure 20.

In Table 2, Column Types of various cross-sectional shapes have been identified as follows:

C-1 = square shape (dicussed in Table 2);

C-2 = H-cross-section shape (discussed in Table 2);

C-3 = X-cross-section shape (discussed in Table 2).

C-4 denotes a cross-sectional column shape which is planar on one side and notched on the other three sides. C-5 denotes a cross-sectional column shape which is planar on three sides and notched on one side. C-6 denotes a cross-sectional column shape which is planar on two adjacent sides and notched on two adjacent sides.

In Table 3, 3 and 4 (RFB-3 or RFB-4) inch offsets have been used in calculating the physical properties of the various depths of grade beams.

In applications where an upper or lower portion or portions of a form panel section or sections is planar, as opposed to having a protrusion or flange, it may be more efficient to eliminate (1) the upper steel panel section (Figure 23, upper left; Figure 32, upper right), or (2) sections (Figures 24, 25, 26, 27, 28 and 29, upper left and right), and/or (3) lower steel of panel section (Figures 25 and 28, lower left), and/or (4) sections (Figures 26 and 27, lower left and right), and simply extend the form ply panel to suit the dimensional requirement of the phanar shape.

Further, in planar application, it may be more efficient to orient all or a portion of the required aluminum sliders (or wales) so as to be positioned horizontally as opposed to vertically (see Figures 27, 28, 29 and

32).

In all applications wherein the top and/or bottom of a form panel terminates in an "A" (planar face section - see lower left of Figure 23) or a "B" panel section (protruding face section - see lower right of Figure 23), it will be necessary to "bridge" the horizontal transition between the A or B panel section and the form ply filler panel component so as to adequately restrain the steel A or B panel sections against significant outward acting pressure developed as freshly batched concrete is placed within the form. More specifically, the "bridging" of the horizontal transition between the steel A and/or B panel section or sections and the form ply filler panel component is accomplished by connecting the top and/or bottom horizontal row of form ties with the next horizontal row of form ties by means of vertically positioned aluminum sliders or wales common to at least both rows of form ties (see Figure 23, bottom left and right and top right; Figures 24 and 29, bottom left and right; Figures 25 and 28, bottom right; Figure 30, bottom and top left and right; Figure 31, left and right sides completely; and Figure 32, left side complete and right bottom.) This varied method of component assembly may apply to the numerous section shapes which may be created including rectangular (Figures 24, 26, 27 and 28), channel sections (Figure 23), I sections (Figure 11), T sections, including inverted T's (Figure 29), L sections (Figure 25), J sections (Figure 30), double and single-sided convex corrugated sections (Figures 31 and 32), concave corrugated sections (Figures 33 and 34), including numerous combinations thereof.

In applications where the planar dimensional requirement is greater than the width or length of standard form ply sheets, the form ply sheets or portions thereof, can be "stacked" to suit the dimensional requirement of the planar shape (see Figure 32, upper right).

Claims (20)

1. A cast-in-place or precast concrete form characterized by:

(a) at least one first member (70), with a web

(84) located on a first side of the first member;

(b) at least one second member (72), with a second web (86) located on the first side of the second member; and

(c) at least one connecting member (98) connecting telescopically the respective first member (70), with the respective second member (72), said telescoping connecting member (98) enabling the first and second members (70 and 72) to be moved relative to one another.

2. A form as claimed in claim 1 wherein an elongated strip (76) is positioned between the two webs.

3. A form as claimed in claim 1 wherein the webs (84,86) are planar and are positioned one above the other.

4. A form as claimed in claim 1 wherein the lower portion of the upper web (90), and the upper portion of the lower web (92), together protrude away from the first and second members (70,72) to form a common protrusion.

5. A form as claimed in claim 1 wherein the first member (70) is elevated relative to the second member (72) and a web (94) extends between the upper and lower webs (102).

6. A form as claimed in claim 1 wherein at least two first members (70) and at least two corresponding second members (72) are arranged spatially from one another in vertical parallel orientation.

7. A form as claimed in claim 6 wherein a strip (78) extends from the top of one first upper member (70) to the top of the other spatially disposed upper member (70), and a second strip (80) extends from the bottom of one lower member (72) to the bottom of the other lower member (72).

8. A form as claimed in claim 1 arranged parallel and opposed to a second concrete form of the same configuration, the first and second webs (84,86) facing one another to define a cavity in which concrete can be poured to form a concrete beam having a rectangular cross-section.

9. A form as claimed in claim 9 wherein the pair of opposed forms are held together by snap-ties (74).

10. A form as claimed in claim 4 arranged parallel and opposed to a second concrete form of the same configuration, the respective protrusions facing one another to define a cavity in which concrete can be poured to form a concrete beam having an "I" cross-section.

11. A concrete form as claimed in claim 1 arranged in parallel and opposed to a second concrete form as claimed in claim 4 wherein the webs of the first form facing the protruding webs of the second form define a cavity in which concrete can be poured to form a concrete beam having an "C" cross-section.

12. A concrete beam formwork construction as claimed in claim 1 comprising:

(a) a first elongated upper section (150) being planar along one side, and a connecting means (158) on the opposite side;

(b) a first elongated lower section (152) being detachably connected to the first upper section with a connecting means (160) therebehind; (c) a second elongated upper section (154) being planar along one side, opposed to and facing the first upper section (150) and a second connecting means (162) on the opposite side; and

(d) a second lower section (156) being detachably connected to the second upper section (154), opposed to and facing the first lower section, with a connecting menas (164) on the opposite side, to form a concrete beam with a rectangular cross-section.

13. A form as claimed in claim 12 including a second upper section (166) and a second lower section (168) which have an elongated protrusion (154) extending in the direction of the first upper and lower sections (150,152), to form a concrete beam with a "C" shaped cross-section.

14. A form as claimed in claim 13 wherein the lower section (152) is removed and the second upper section (166) is removed, to form a concrete beam with an "L" shaped cross-section.

15. A form as claimed in claim 12 wherein the first lower section (152,160) is removed and the second lower section (156,164) is removed, to form a concrete beam with a rectangular cross-section.

16. A form as claimed in claim 15 wherein the first connecting means (158) and the second connecting means (162) are arranged horizontally to form a concrete beam with a rectnagular cross-section.

17. A form as claimed in claim 12 wherein the first connecting means (158) is arranged horizontally and the first lower section (160) is removed to form a concrete beam with a rectangular cross-section.

18. A form as claimed in claim 13 wherein the first lower section (152) is replaced by a first protruding lower section (168), the connecting means (158,162) are truncated, and the upper connecting means (158,162) are arranged horizontally, to form a concrete beam with an inverted "T" cross-section.

19. A form as claimed in claim 14 including a first upper protruding section (166) and a second upper protruding section (170) to form a concrete beam with a "J" cross-section.

20. A form as claimed in claim 13 arranged in tandem with at least one second form of the same configuration to form a concrete beam with a corrugated configuration.