Concrete slab dowel system and method for making same

A concrete dowel slab joint system is provided for maintaining adjacent sections of concrete in alignment during contraction and expansion of the concrete, and for transferring shear stresses and bending moments across a joint formed between adjacent concrete slabs. It includes a sleeve assembly for receiving and maintaining the dowel bar therewithin. In this is way, the dowel bar does not transmit substantial shear stresses to the concrete during the contraction and expansion of the concrete. The sleeve assembly comprises an elongate sleeve body having an outer surface and an inner surface, and defines a hollow interior compartment, (b) at least one closed end, and (c) a sleeve member. Preferably, at least one collapsible spacer member is located within the hollow interior compartment. The spacer member is collapsible by interactive forces exerted by the dowel bar moving in a lateral and/or longitudinal path within the hollow interior compartment in response to the expansion and contraction of the concrete. The inner surface defines a hollow interior chamber. The longitudinal axis of the sleeve body is disposed substantially at a right angle with respect to the longitudinal axis of the sleeve member. The first sleeve assembly is mountable onto upright support stanchion so that each upright support stanchion is disposed within the hollow interior chamber. The concrete dowel slab joint system of the present invention can include a second sleeve assembly.

BACKGROUND OF THE INVENTION 
This invention relates to dowel and tying bars, and to construction joints 
for transferring stresses across a joint between concrete constructions. 
Concrete responds to changes in temperature and moisture when movement 
associated with these changes (or for other reasons such as internal 
chemical reaction) is restrained. In these instances stresses develop that 
can lead to cracking. To control cracking, joints are built at interval 
distances short enough to maintain stresses below critical values. 
Transverse joints are saw cut, placed through induced cracking, or formed 
at pre-determined spacings. 
Concrete pavements for highways, airport runways and the like are generally 
placed in strips or lanes with a longitudinal joint formed between 
adjacent strips or lanes. Concrete is poured in the first strip and 
allowed to cure. Subsequently, concrete is poured and cured in the 
adjacent strip and so on until the concrete pavement is completed. A 
longitudinal joint is formed between adjacent strips to facilitate 
construction and to reduce stresses and control cracking caused by 
contraction or expansion of the concrete. Transverse or slug joints are 
also formed in concrete by cutting or sawing the concrete at a given 
location and to a given depth. 
Similarly, joints are formed in concrete structural slabs, walls, footings 
and the like to minimize stresses and/or simplify construction methods. Of 
these joints, there are several types. For example, the expansion joint 
provides a space between slabs to allow for expansion or swelling of the 
slab as temperature and moisture increase or growth due to any cause 
occurs. A construction joint provides a finished edge or end so that 
construction operations interrupted for some length of time may be 
continued or resumed without serious structural penalty. 
Load is transferred across a joint principally by shear. Some bending 
moment may be transferred across the joints through tie joints. Good load 
transfer capability must be built into the joint, or the load carrying 
ability of the concrete slab or structure will be reduced. The alternative 
is to strengthen the concrete by improving support or increasing depth to 
minimize the joint load transfer weakness. 
Tie bars and dowels are often used in concrete design to improve load 
transfer at the joint between concrete slabs or structures. Such tie bars 
and dowels are embedded in the concrete and arranged across the joint in a 
direction substantially perpendicular to the axis defined by the joint. 
Various approaches, depending on the type of tie bar or dowel, have been 
suggested with respect to concrete construction joints. 
In the construction of concrete slabs on grade, it is common practice to 
install continuous side forms with dowels for future adjacent slab 
concrete placement and to place concrete in long continuous strips. It is 
also known to place slab dowels and sleeves at specified distances across 
the strips to allow the strips to have a controlled plane to accommodate 
shrinkage of the concrete. The positions of these dowel locations are 
marked on the side forms and the concrete after placement and finishing is 
struck to provide a joint at these locations, or is later sawn. This 
allows for a smooth controlled joint across the slab strip. However, many 
times the marks are destroyed and joints are placed in the wrong areas 
negating the advantages of the slab dowels. 
The functions of the tie bars and dowels are to keep contiguous sections of 
concrete in alignment during contraction and expansion, and to transfer 
shear stresses and bending moments across the joint between the two slabs. 
The prior art dowels are often made smooth, lubricated, or coated entirely 
with plastic as disclosed in U.S. Pat. No. 3,397,626 to prevent the dowel 
from bonding to the concrete and allow the concrete slab or structure to 
slide relative to the dowel in a direction substantially perpendicular to 
the axis defined by the joint. Such movement of the slab relative to the 
dowel prevents build up of stress in the dowel that may result in cracking 
of the concrete. 
In an alternative construction disclosed in U.S. Pat. No. 4,449,844, the 
dowel has its outer ends bonded to concrete and its central portion 
covered with plastic to prevent bonding to concrete. The dowel disclosed 
in Larsen performs a latent spring function to limit the movement of the 
concrete slab relative to the dowel when temperature changes cause the 
length of the slab section to vary with time. 
A major disadvantage of the above prior art dowels and tie bars is that 
they prevent movement of the concrete slab relative to an adjacent 
concrete slab in a direction substantially parallel to and aligned with 
the axis defined by the joint. In such situations, the dowels and tie bars 
provide enough restraint against movement and shrinkage so that the 
concrete slab or structure induces stresses along a line substantially 
defined by ends of the dowels or tie bars. This problem is most evident in 
the situation when adjacent concrete slabs or strips are placed and cured 
in repetitive order or when adjacent concrete slabs or structures are 
subjected to extreme temperature differences. 
For example, it is well known that concrete typically shrinks after 
placement. If a second concrete paving slab is placed adjacent to a first 
concrete paving slab that has contracted from thermal and drying 
shrinkage, the second concrete paving slab will likewise attempt to shrink 
similar to the shrinkage of the first concrete paving slab. However, 
dowels and tie bars arranged across the joint between the first and second 
concrete paving slabs will restrain the second concrete paving slab from 
shrinking during curing. The developed internal stress in the second 
concrete paving slab can create an undesirable condition that may result 
in cracking. Even if cracks do not develop, the internal stresses are 
added to the stress from the normally applied design loads and could 
reduce the service life of the pavement. 
Another prior art slab dowel system, U.S. Pat. No. 4,578,916, relates to a 
connecting and pressure-distributing element for two structural members to 
be concreted one after the other in the same plane and separated by a 
joint, of the type having a socket and a bar insertable into the opening 
of the socket. The socket is inserted for attachment to a frontal concrete 
form and for embedding in the structural member to be concreted first. The 
bar is inserted in the socket hole and is intended for embedding in the 
structural member to be concreted later. The bar is at least two closed 
loops each of generally rectangular shape and made from reinforcing rods. 
The loops are secured to the socket and the bar, respectively, in one case 
by welding, in another case by means of a holder. Because they are 
symmetrically spaced from the socket and the bar, they ensure good 
distribution of pressure within the concrete. 
An improved tying bar and joint construction for transferring stresses 
across a joint between concrete slabs or structures and accommodating for 
shrinkage and expansion of concrete is provided in U.S. Pat. No. 
4,733,513. The subject bar has a resilient facing attached to at least one 
side of the bar so that the concrete slab or structure can move in 
relationship to the bar in a direction substantially perpendicular to the 
resilient facing. The bar is arranged across the joint in a direction 
substantially perpendicular to the axis defined by the joint. 
In U.S. Pat. No. 5,005,331, slip and non-slip dowel placement sleeves are 
disclosed. The slip dowel placement sleeve generally comprises a tubular 
dowel receiving sheath having a closed distal end and an open proximal 
end. A connecting means of perpendicular flange is formed around the 
proximal opening of the sheath to facilitate attachment of the sheath to a 
concrete form. Smooth sections of dowel rod may then be advanced through 
holes drilled in the concrete form and into the interior compartment of 
the sheath. Concrete is poured within the form and the dowel rod remains 
slidably disposed within the interior of the sheath. Variations of the 
basic slip dowel placement sleeve of the invention includes a tapered 
"extractable" sleeve and a corrugated "grout tube" for placement of 
non-slip dowel or rebar. 
Slip and non-slip dowel placement sleeves are disclosed in U.S. Pat. No. 
5,216,862. The slip dowel placement sleeve generally comprises a tubular 
dowel receiving sheath having a closed distal end and open proximal end. A 
connecting means is formed around or inserted into the proximal opening of 
the sheath to facilitate attachment of the sheath to a concrete form. 
Smooth sections of dowel rod may then be advanced through holes drilled in 
the concrete form and into the interior compartment of the sheath. 
Concrete is poured within the form and the dowel rod remains slidably 
disposed with the interior of the sheath. Variations of the basic slip 
dowel placement sleeve of the invention include a tapered extractable 
sleeve and a corrugated grout tube for placement of non-slip dowel or 
rebar. 
SUMMARY OF THE INVENTION 
It has now been determined that cracking problems in reinforced concrete 
slabs, caused by substantial shear stresses imparted to the concrete by 
movement of dowel bars located therewithin during expansion and 
contraction of the concrete slab, can be avoided. More specifically, the 
cracking problem can be avoided by employing a concrete dowel slab joint 
system of the present invention which permits the dowel bar to undergo 
movement in both a lateral and longitudinal direction without imparting 
substantial shear stress to the concrete itself. 
The subject concrete dowel slab joint system comprises a dowel bar for 
maintaining adjacent sections of concrete in alignment during contraction 
and expansion of the concrete, and for transferring shear stresses and 
bending moments across a joint formed between adjacent concrete slabs. It 
also includes a sleeve assembly for receiving and maintaining the dowel 
bar therewithin. In this way, the dowel bar does not transmit substantial 
shear stresses to the concrete during the contraction and expansion of the 
concrete. 
The sleeve assembly comprises an elongate sleeve body having an outer 
surface and an inner surface, and defining a hollow interior compartment, 
(b) a pair of closed ends, and (c) collapsible spacer members located 
within the hollow interior compartment. The collapsible spacer members 
engage and position the dowel bar at a lateral distance from the inner 
surface of the elongate sleeve body and at a longitudinal distance from 
the closed ends. These lateral and longitudinal distances together define 
an expansion area between the dowel bar and the sleeve assembly. The 
spacer members are collapsible by interactive forces exerted by the dowel 
bar moving in a lateral and/or longitudinal path within the hollow 
interior compartment in response to the expansion and contraction of the 
concrete. The sleeve assembly is also designed to prevent concrete from 
entering the hollow interior compartment during use in receiving and 
maintaining the dowel bar therewithin. 
The concrete dowel slab joint system of this invention includes a hollow 
interior compartment which preferably has a square, round, or rectangular 
cross-sectional configuration. Moreover, the elongate sleeve body is 
typically fabricated from a polymeric material. Moreover, the collapsible 
spacer members are preferably fabricated from a polymeric material which 
is crushable by interactive forces exerted by the dowel bar as it is moved 
in a lateral and/or longitudinal path within the hollow interior 
compartment in response to the expansion and contraction of the concrete. 
The spacer members can be attached to the inner surface of the closed ends 
thereby defining a longitudinally-extending expansion area between the 
dowel and the closed ends. In a preferred case, at least one of the closed 
ends comprise a removable end closure. 
Preferably, the concrete dowel slab joint system of this invention includes 
at least one generally V-shaped spacer member located within the hollow 
interior compartment. The V-shaped spacer member includes a pair of 
outwardly angularly extending side sections having a pair of free ends 
joined together at the other end of the side sections to form a base. The 
base of the V-shaped spacer member is attached to an inner surface of the 
closed end, and the pair of free ends are joined to the inner surface of 
the elongate sleeve body, and one of the ends of the dowel bar engages an 
inner surface of the outwardly angularly extending side sections. Thus, 
the V-shaped spacer member configuration defines the expansion area 
between the dowel bar and the elongate sleeve body. In one form of this 
structure, the base of the generally V-shaped spacer member comprises a 
flat rectangular base section, and the opposed ends of the flat 
rectangular base section are joined to the other end of the side sections 
to form the generally V-shaped spacer member arrangement. 
The subject concrete dowel slab joint system can also include positioning 
elements attached at one end to the sleeve assembly. The other end of the 
positioning elements will then extend upwardly to a point above the 
surface of the concrete. The positioning elements act as a visible 
locating indicator of the concrete dowel slab joint system. Preferably, 
the positioning elements comprise flexible elongate rod which are 
typically fabricated of a polymeric material. 
In another preferred form of the present invention, the sleeve assembly 
comprises a plurality of interlocking sleeve body sections connected one 
to the other to form a unitary sleeve body structure. Preferably, the 
sleeve assembly comprises a pair of interlocking sleeve body sections each 
having a closed distal end and an open proximal end to which a flange is 
attached. The flange, which extends perpendicularly about the proximal end 
of each of the body sections, has formed therein a central aperture sized 
to permit passage of the dowel bar through the flange and into the 
confines of the hollow interior compartment. A clamping mechanism 
interlocking connects the flange of one sleeve body section to the flange 
of the other sleeve body section. 
In a preferred embodiment, the first sleeve assembly comprises (a) an 
elongate sleeve body having a longitudinal axis and including an outer 
surface and an inner surface, and defining a hollow interior compartment, 
(b) at least one closed end, and (c) a sleeve member joined to said 
elongate sleeve body or to said closed end and having a longitudinal axis, 
at least one open outer end, an outer surface and an inner surface, the 
inner surface defining a hollow interior chamber and the longitudinal axis 
of sleeve body being disposed substantially at a right angle with respect 
to the longitudinal axis of sleeve member, the first sleeve assembly being 
mountable onto an upright support stanchions so that the upright support 
stanchion is disposed within the hollow interior chamber. The concrete 
dowel slab joint system of the present invention also preferably includes 
a second sleeve assembly. 
The present invention preferably further comprises a second sleeve assembly 
including a sleeve body having a longitudinal axis, a closed end, an outer 
surface and an inter surface. The elongate sleeve body defines a hollow 
interior compartment. Preferably, the sleeve body of the second sleeve has 
a longitudinal length which is shorter than the longitudinal length of the 
sleeve body of the first sleeve assembly. This second sleeve assembly also 
includes a sleeve member having a longitudinal axis, at least one open 
outer end, an outer surface and an inner surface. The inner surface 
defines a hollow interior chamber. The longitudinal axis of sleeve body is 
typically disposed substantially at a right angle with respect to the 
longitudinal axis of sleeve member. The second sleeve assembly is 
mountable onto an upright support stanchion so that the upright support 
stanchion is disposed within the hollow interior chamber. 
The foregoing and other objects, features and advantages of the invention 
will become more readily apparent from the following detailed description 
of a preferred embodiment which proceeds with reference to the drawings.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
Conventional slab dowels are positioned within concrete sections. In a 
typical concrete formation sequence, the first concrete slabs and second 
concrete slabs are poured in sequence. Transverse joints are then saw cut 
or formed through methods well known in the prior art to reduce and/or 
relieve stresses in the concrete and prevent cracking. A longitudinal 
joint is formed between the two concrete strips comprising the first 
concrete slab and the second concrete slab. 
Dowel bars are embedded in the concrete slabs for maintaining adjacent 
sections of concrete in alignment during contraction and expansion of the 
concrete, and for transferring shear stresses and bending moments across a 
joint formed between adjacent concrete slabs. The cross-sectional sizes 
and lengths of the dowel bars vary depending on the types of installation 
and the required forces to be counteracted. The dowel bars are placed and 
supported with respect to transverse joints and longitudinal joint. 
As depicted in FIG. 1, sleeve dowel bar assemblies are embedded in the 
first concrete slabs, and arranged across the transverse transfer joint, 
22a to 22e and, 23a to 23e, in a direction substantially perpendicular to 
the axes defined by the transverse transfer joint. Similarly, dowel 
sleeves are embedded in the first concrete slabs and arranged across the 
joint in a direction substantially perpendicular to the axes defined by 
the longitudinal transfer joint 24a to 28a, etc. In a typical installation 
sleeve, dowel bars assembly 32 are positioned on the rebar-matrix, and the 
concrete slab is poured. The concrete slab is allowed to harden in situ 
with the sleeve dowel bars assembly and dowel sleeves embedded therein. 
After the first concrete slab has undergone expansion or contraction from 
thermal or drying shrinkage, the second concrete slab is placed adjacent 
to the first concrete slab after the dowel bars are inserted into the 
sleeves previously placed in the prior concrete pour so that the dowel 
bars are also essentially embedded in the second concrete slabs. The 
second concrete slab will attempt to shrink during curing in a similar 
manner to the shrinkage of the first concrete slab. 
In a conventional installation, the dowel bars arranged across longitudinal 
joints between the first and second concrete slabs will attempt to 
restrain the second concrete slabs from movement. The developed and 
internal stress in the second concrete slab can create an added stress 
which may cause cracking by itself or when added to an applied load upon 
the slabs. The cracks will often develop along a line near the ends of the 
dowels bars. Referring now to FIG. 1, an illustrative reinforced concrete 
slab section 10 is shown which includes two versions of the concrete dowel 
slab joint system of the present invention in place of conventional dowel 
bars previously discussed. In a first version, denoted 18, a dowel bar 20 
is positioned within a single sleeve body 30. This first version is used 
to bridge longitudinal joints, for example, the joints formed between 
adjacent slab segments 12a, 14a, 16a, etc. In a second version, denoted 
19, a dowel bar 20 is positioned within the confines of a pair of sleeve 
body 30. The second version is employed to bridge transverse joints 22a, 
22b, 22c etc. 
A reinforced concrete slab section 10 comprises a concrete slab and may 
include an interconnected matrix of reinforcing re-bar rods (not shown). 
The matrix of reinforcing re-bar rods are arranged in a predetermined 
pattern according to known principals of structural engineering. 
As shown more specifically in FIGS. 6 and 7, the reinforcing re-bar rods 55 
are held in position by wire ties 46. The rods 55 are maintained at a 
predetermined relative height by re-bar rod supports 54. The slab 
reinforcing re-bar rods 55 are held in position atop the re-bar supports 
54 by wire ties 46. Saw cut or slug joints 22a-22e and 23a-23e, 
respectfully, in the concrete slab and partitions it into respective 
rectangular segments 12a-12d, 14a-14d and 16a-16d, respectfully. The 
concrete dowel slab joint systems 19 of the present invention can be 
embedded in the concrete slab section 10, and can be arranged in position 
across a transverse joint in a direction substantially perpendicular to an 
axis defined by the joint. As previously described, in a typical 
installation, each concrete dowel slab joint system 19 is centrally 
positioned, and the concrete slab is poured and hardens in situ with the 
concrete dowel slab joint system embedded therein. 
When the prior art dowel bars are replaced by the concrete dowel slab joint 
systems 18 and 19 they are held in firm position and resists displacement 
of one concrete slab relative to the other as in the case of conventional 
dowel bars. The concrete dowel slab joint systems 18 and 19, unlike its 
prior art counterparts, allows the slabs to move laterally and 
longitudinally with respect to each other without inducing substantial 
stresses within the slabs or on the dowel bar, respectively. 
Referring now to FIGS. 2-5, the concrete dowel slab joint systems 18 and 19 
of this invention are depicted, FIGS. 2-5 and 7 showing systems 18 and 
FIGS. 6, 8 & 9 showing system 19. More specifically, the systems 18 & 19 
retain dowel bar 20, which is typically a conventional elongate steel 
dowel bar having a square rectangular round or oval cross-sectional area, 
and maintains bar 20 in position within sleeve assembly section 32. Sleeve 
assembly 32 receives and maintains dowel bar 20 within its confines 
without inducing shear stresses within concrete slab 10. More 
specifically, sleeve assembly section 32 comprises an elongate sleeve body 
30 having a closed end 36, an outer surface 38 and an inter surface 40. 
The elongate sleeve body 30 defines a hollow interior compartment 42. It 
should be noted that the closed end 36 can comprise either a rectangular 
end piece 33 (see FIG. 2) sized to fit flush with the rectangular opening 
at the ends of the elongate sleeve body, or a rectangular shaped cap (not 
shown) which tightly nests about the respective ends of elongate sleeve 
body. 
At the end of the hollow inner compartment 42, and attached to the inner 
surface of the closed end section 36 and elongate sleeve body 30, 
respectively, are located collapsible spacer member 44. As more 
specifically shown in FIG. 2, a collapsible spacer member 44 maintain 
dowel bar 20 in an initial position at predetermined lateral distance "X" 
from the inner surface 40 of the elongate sleeve body 30. Collapsible 
spacer member 44 also maintain dowel bar 20 at a longitudinal distance "Y" 
from the closed ends 36 the respective lateral and longitudinal distances, 
X and Y, between the dowel bar 20 and the inner surfaces 40 of the 
elongate sleeve body 30 and closed end 36 define there between and 
expansion area for movement of the dowel bar 30 during expansion and 
contraction of the reinforced concrete slab section 10. 
Collapsible spacer members 44 are generally in the form of V-shaped inserts 
which comprise a flat base section 48 and a pair of outwardly angularly 
extending side sections 50, one end of the side sections 50 being joined 
to the ends of the flat base section 48 and the other end of the side 
sections 50 being a free end. The flat base section 48 is joined to the 
inner surface of the closed end 36, and the free end of the outwardly 
angularly extending side sections 50 are attached to the inner surface 40 
of the elongate sleeve body 30. 
Concrete dowel slab joint system 19 is comprised of a pair of substantially 
identical sleeve assembly sections 32 which are connected one to the 
other. Moreover, section 32 of slab joint dowel system 19 are disconnected 
one from the other for purposes of inserting dowel bar 20 into hollow 
inner compartment 42. 
As shown, more specifically in FIGS.9, the respective section 32 of systems 
19 are connected engaged one to the other by a clamping assembly 70 & 72. 
The section 32 of system 19 each having a closed distal end 46 and an open 
proximal end 47, a flange 62 being attached to and extending 
perpendicularly about the proximal end 47 of each of the body section 30. 
Flanges 62 each have formed therein a central aperture 64 sized to permit 
passage of dowel bar 20 through flange 62 and into the confines of the 
hollow interior compartment 42. Clamping assembly 70 located adjacent to 
the top and bottom surfaces of flange 62. Flange 62 includes a central 
rectangular slot 68 having a complementary inner rectangular dimension as 
the cross sectional dimension of elongate sleeve body 30. The inner edges 
of rectangular slot 68 are joined to the open end 47 of sleeve assembly 
32. 
To form concrete dowel slab joint system 19, dowel bar 20 is introduced 
into the hollow interior compartment 42 of either one of the section 32. 
Sections 32 are then interlockingly joined together by engaging the outer 
surfaces of flanges 62 of each section 32, and interlockingly engaging 
clamp caps 70 about the top and bottom ends of engaged flanges 62, clamps 
caps 70 interlockingly extending about flanges 62. Flanges 62 include pin 
63 which pass through aperture 64 in flange 62 to connect clamp caps 70 to 
flanges 62. The upper clamp cap 72 can comprise upwardly extending 
flexible positioning elements 80. The elongate U-shaped clamp caps 70 & 72 
are sized to extend over the top and bottom edges of flanges 62 and 5 to 
be interlockingly connected to flanges 62 by pins 63 so that sections 32 
are held together in interlocking engagement during the entire procedure 
for producing concrete slab section 10. Thus, dowel bar 20 is positioned 
with section 30 so that it engages the collapsible spacer members 44, 
without collapsing same. In this way, dowel bar 20 is maintained at a 
lateral distance "X" from the inner surface of the elongate sleeve body 
30, and at a longitudinal distance GYM from the closed ends 36 thereby 
defining an expansion area between the dowel bar 20 and the sleeve 
assembly 32. Furthermore, the sleeve assembly 32 is maintained so that it 
prevents concrete from entering the hollow interior compartment 42 during 
use in receiving and maintaining the dowel bar 20 therewithin. 
When concrete slab section 10 is formed positioning elements 80, in the 
form of flexible rods, will extend upwardly out from the upper surface of 
concrete slab 32 thereby indicating the position within the concrete 
section 10 of slab joint dowels system 19. Re-bar support members 54 are 
optionally attached to the outer bottom surface of elongate sleeve body 32 
for saw cut or slug joint construction. Re-bar support members 54 have a 
complementary shape to slab reinforcing re-bar rods 55, and are designed 
to maintain slab joint dowel system 32 in place atop the slab reinforcing 
re-bar rods 55. Moreover, slab joint dowel system 19 is further maintained 
in position atop slab reinforcing re-bar rods 55 through the use of wire 
ties 46. 
Referring now to FIG. 7, dowel slab joint systems 18 are assembled by first 
mounting support clamps 54 of body section 30 onto rebar 55. An edge form 
50 is constructed. Then the flanges 62 are attached to the edge form 50 by 
inserting fasteners 66 through apertures 64 and into edge form 50. 
Alternatively, flange 62 can have a self-adhering adhesive surface 65, 
with pull off protection cover 67 which adheres. A first concrete slab is 
then poured over the previously mounted body section 32 within the 
confines of the edge form 50. After the concrete slab is cured, the form 
is removed exposing central slots 68 of body sections 32. Dowel bars 20 
are inserted into open slots 68 and a second concrete slab is poured 
adjacent to the first cured concrete slab, a longitudinal construction 
joint being located between the adjacent first and second concrete slabs. 
In use, the dowel bar 20 remains in position engaging the collapsible space 
members 44 until substantial expansion and contraction of the concrete 
slabs take place. Then, the dowel bar 20 will be moved in response to the 
expansion and contraction of the concrete slab section 10 thereby 
collapsing the spacer members 44 which moves the dowel bar 20 in a lateral 
and/or longitudinal path within the hollow interior compartment 42. Thus, 
when interactive forces are exerted on a dowel bar 20 located within the 
aforementioned expansion area, the dowel bar does not transmit substantial 
shear stresses to the concrete or tie dowel during contraction and 
expansion of the concrete. 
In another form this invention, referring to FIGS. 10-13, a dowel sleeve 
system 100 is provided which is similar to system 18 as described above. 
The dowel sleeve system 100 is supported atop a support frame system 200. 
The dowel sleeve system 100 comprises first and second sleeve assembly 110 
and 130, respectively. 
First sleeve assembly 110 comprises an elongate sleeve body 112 having a 
longitudinal axis denoted "X", a closed end 114, an outer surface 116 and 
an inter surface 118. The elongate sleeve body 112 defines a hollow 
interior compartment 120. Located toward the closed end 114, and attached 
to the outer surface 116 of sleeve body 112, is a sleeve member 122. 
Sleeve member 122 has a longitudinal axis denoted "Y", an opened end 124, 
an outer surface 126 and an inter surface 128. Sleeve body 112 and sleeve 
member 122 each have a substantially rectangular cross-sectional area. The 
longitudinal axis of sleeve body 112 is disposed substantially at a right 
angle to the longitudinal axis of sleeve body 122. 
Second sleeve assembly 130 comprises a sleeve body 132 which have a shorter 
longitudinal length than sleeve body 30, and a longitudinal axis denoted 
"A". It also has a closed end 134, an outer surface 136 and an inter 
surface 138. The elongate sleeve body 132 defines a hollow interior 
compartment 140. Located toward the closed end 134, and attached to the 
outer surface 136 of sleeve body 132, is a sleeve member 142. Sleeve 
member 142 has a longitudinal axis "B", an opened end 144, an outer 
surface 146 and an inter surface 148. Sleeve body 132 and sleeve member 
142 each have a substantially rectangular cross-sectional area. The 
longitudinal axis of sleeve body 132 is disposed substantially at a right 
angle to the longitudinal axis of sleeve body 142. 
As shown in FIG. 10, at the end of the hollow inner compartment 120, and 
attached to the inner surface of the closed end section 114 and elongate 
sleeve body 112, respectively, is located collapsible spacer member 180. 
Collapsible spacer member 180 is similar in design and function to 
collapsible spacer member 44. Spacer member 44 is specifically shown in 
FIG. 2 and is described in detail above. In use, dowel bar 20 is located 
in an initial position at predetermined lateral distance from the inner 
surface 118 of the elongate sleeve body 112. Collapsible spacer member 180 
also maintains dowel bar 20 at a longitudinal distance from the closed end 
114. The respective lateral and longitudinal distances between the dowel 
bar 20 and the inner surfaces of the elongate sleeve body 112 and closed 
end 114 define therebetween an expansion area for movement of the dowel 
bar 20 during expansion and contraction of the reinforced concrete slab 
section 10. 
Flange 150 has formed therein a central aperture 152 sized to permit 
passage of dowel bar 20 through flange 150 and into the confines of the 
hollow interior compartment 120. Clamping assembly 160 located adjacent to 
the top and bottom surfaces of flange 150. The clamping assembly 160 
comprises upwardly extending flexible positioning elements 162. 
In further form this invention, referring to FIGS. 14-17, a dowel sleeve 
system 300 is provided which is similar to system 100 as described above. 
In this case the dowel sleeve system 300 is also supported on support 
frame system 200. The dowel sleeve system 300 also comprises a first and 
second sleeve assembly 310 and 330, respectively. Generally, the 
difference between respective dowel sleeves systems 100 and 300 resides in 
sleeve 322 and 342. Referring again to FIGS. 14-17 first sleeve assembly 
310 comprises an elongate sleeve body 312 having a longitudinal axis 
denoted "X'", a closed end 314, an outer surface 316 and an inter surface 
318. The elongate sleeve body 312 defines a hollow interior compartment 
320. Attached to the closed end 314 is a sleeve member 322. Sleeve member 
322 has a longitudinal axis denoted "Y'", opened end 324 and 325, an outer 
surface 326 and an inner surface 327 defining a hollow chamber 328. Sleeve 
body 312 and sleeve member 322 each have a substantially rectangular 
cross-sectional area. The longitudinal axis of sleeve body 312 is disposed 
substantially at a right angle to the longitudinal axis of sleeve body 
322. 
Second sleeve assembly 330 comprises a sleeve body 332 which has a shorter 
longitudinal length than sleeve body 312, and a longitudinal axis denoted 
"A'". It also has a closed end 334, an outer surface 336 and an inter 
surface 338. The elongate sleeve body 332 defines a hollow interior 
compartment 340. Attached to closed end 334 is a sleeve member 342. Sleeve 
member 342 has a longitudinal axis "B'", an opened end 344 and 345, an 
outer surface 346 and an inner surface 347 which defines a hollow chamber 
348. Sleeve body 332 and sleeve member 342 each have a substantially 
rectangular cross-sectional area. The longitudinal axis of sleeve body 332 
is disposed substantially at a right angle to the longitudinal axis of 
sleeve body 342. 
As shown in FIG. 14-16, at the end of the hollow inner compartment 320, and 
attached to the inner surface of the closed end section 314 and elongate 
sleeve body 312, respectively, is located collapsible spacer member 380. 
Collapsible spacer member 380 is similar in design and function to 
collapsible spacer member 44 and 180, respectively. In use, dowel bar 20 
is located in an initial position at predetermined lateral distance from 
the inner surface 318 of the elongate sleeve body 312. Collapsible spacer 
member 380 also maintains dowel bar 20 at a longitudinal distance from the 
closed end 314. The respective lateral and longitudinal distances between 
the dowel bar 20 and the inner surfaces of the elongate sleeve body 312 
and closed end 314 define therebetween an expansion area for movement of 
the dowel bar 20 during expansion and contraction of the reinforced 
concrete slab section 10. 
Flange 350 has formed therein a central aperture 352 sized to permit 
passage of dowel bar 20 through flange 350 and into the confines of the 
hollow interior compartment 320. Clamping assembly 360 located adjacent to 
the top and bottom surfaces of flange 350. The clamping assembly 360 
comprises upwardly extending flexible positioning elements 362. 
System 100 and 300 also comprise a support frame system 200. As depicted in 
FIGS. 10-13 and FIGS. 14-17, support frame system 200 is typically a wire 
support frame system fabricated of metal such as steel or the like and 
joined together by welding the various support frame components. Support 
frame 200 comprises a horizontal base section 210 and a plurality of 
upright support stanchions 220. Horizontal base section 210, which 
includes a longitudinal axis and a lateral axis, comprises longitudinally 
extending support members 212 joined to laterally-extending support 
members 214 to form an integral horizontal support frame. In order to 
provide further stability to the horizontal support frame, flat elongate 
pads 216, typically fabricated of a polymeric material, are connected to 
the longitudinally extending support members 212. For example, snap-on 
connectors 218 can be connected to the elongate pads 216 for fitting 
attachment to the longitudinally extending support members 212. In the 
case of the integral support structure 230 described below, the snap-on 
connectors 218 attached to these elongate pads 216 can also be employed to 
join together all of the individual support structures of this invention. 
Upright support stanchions 220 comprise an inverted Y-shaped configuration. 
The outer ends 224 of the angularly-extending Y-shaped arms 222 are joined 
to longitudinally extending support members 212 and the inner ends 226 of 
the angularly-extending arms 222 are joined together to form an upright 
support member 228. 
As more specifically denoted in FIG. 12, upright support stanchions 220 and 
a pair of laterally-extending support members 214 form a single integral 
support frame 200. A pair of these support frames 200 are assembled into a 
single unitary system by connecting same together using a coupler sleeve 
250, fabricated of metal or of a polymeric material, to join the ends of 
the laterally-extending support members 214 of each of the respective 
support frames 200. 
To assemble the dowel sleeve system 100, support frame 200 is first 
assembled in a form as described above. Next, dowel bar 20 is inserted 
into hollow interior compartment 120, 320 of first sleeve assembly 110,210 
and hollow interior compartment 140,340 of second sleeve assembly 130,330, 
respectively. Then, the first and second sleeve assemblies containing the 
dowel bar 20 are mounted onto the upright support stanchions 220. This 
mounting operation is accomplished by introducing the sleeve members 
122,322 and 142,342 onto the upright support members 228, and then 
mounting the first and second sleeve assemblies onto upright support 
stanchions 220. This can be done by moving the sleeve members 122,322 and 
142,342 to an interlocking engaging position on support stanchions 220 in 
this case, by sliding the inner surfaces 127,327 and 147,347 of sleeve 
members 122,322 and 142,342 onto the upright support members 228 so that 
upright support members 228 are located within hollow chambers 128,328 and 
148, 348 until frictional engagement is achieved. 
Referring now to FIGS. 18-20, a dowel slab joint system 400 is provided. 
Welded wire support system 410 is typically a wire support frame system 
fabricated of metal such as steel or the like and joined together by 
welding the various support frame components. Welded support frame system 
410 comprises a horizontal base section 415 and a plurality of upright 
support stanchions 420. Upright support stanchions 420 comprise an 
inverted Y-shaped configuration. The outer ends 424 of the 
angularly-extending Y-shaped arms 422, which form support legs 425, are 
joined to longitudinally extending support members 412 and the inner ends 
426 of the angularly-extending arms 422 are joined together to form an 
upright support member 428. 
In, for example, a double expansive dowel systems for pre-stressed slab as 
depicted in FIG. 19 or a single expansive dowel system as depicted in FIG. 
20, a first sleeve assembly 310, as described above, which includes an 
elongate sleeve body 312 defining a hollow interior compartment 320, a 
closed end 314, an outer surface 316 and an inner surface 318 has a sleeve 
member 322 attached to the closed end 314. Sleeve member 322 is described 
in detail above. A flange 350 is also joined to the open end of elongate 
sleeve body 312. Flange 350 has formed therein a central aperture 352 
sized to permit passage of dowel bar 20 therethrough and into the confines 
of the hollow interior compartment 320. Holes 355 are located near the 
respective corners of flange 350. As shown in FIG. 18, at the end of the 
hollow inner compartment 320, and attached to the inner surface of the 
closed end section 314 and elongate sleeve body 312, respectively, is 
located collapsible spacer member 380. Collapsible spacer member 380 is 
similar in design and function to collapsible spacer member 44 which is 
described in detail above. 
The first sleeve assemblies are mountable onto upright support stanchions 
220. This mounting operation is accomplished by introducing sleeve member 
322 onto upright support members 228. Flange 350 is connected to one side 
of an edge form 375 using attachment means such as nails, tacks, staples, 
screws or the like. For example, one could insert a nail through openings 
352 into edge form 375. This will maintain first sleeve 310 in place with 
flange 350 secured against edge form 375. 
A first concrete slab is then poured over the previously mounted body 
section 310 within the confines of the edge form 375. After the concrete 
slab is cured, the form is removed exposing hollow interior compartment 
320. A dowel bar 20 can inserted into hollow interior compartment 320. 
Then, a second concrete slab can be poured adjacent to the first cured 
concrete slab. In this configuration, a longitudinal construction joint 
being located between the adjacent first and second concrete slabs. In the 
case of the double expansive dowel system for pre-stress slabs, a second 
sleeve assembly 390 which is similar in configuration to first sleeve 
assembly 310 is introduced about dowel bar 20 so that flange 350 is 
directly engages the other side of edge form 375. Attachment means, as 
previously described herein, are used to connect flange 350 and in turn 
second sleeve assembly 390 to edge form 375. Once the second sleeve 
assembly 390 is connected to the edge form 375, the second concrete slab 
can be poured. 
Having illustrated and described the principles of my invention in a 
preferred embodiment thereof, it should be readily apparent to those 
skilled in the art that the invention can be modified in arrangement and 
detail without departing from such principles. I claim all modifications 
coming within the spirit and scope of the accompanying claims.