Abstract:
An apparatus for fixing an orientation of a duct in concrete segmental construction has an elongated body, a frame having an inner surface facing the elongated body, and an angle adjusting means connecting the inner surface of the frame to the elongated body. The elongated body is orientable relative to the frame about the ball joint. The angle adjusting means includes a pin extending through the frame, a ball mounted on the pin, and a flange mounted to the ball so as to be in surface-to-surface contact with an end of the elongated body. The pin is operably connected to the ball so as to fix an orientation of the flange.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation-in-part of U.S. patent application Ser. No. 11/861,166, filed on Sep. 25, 2007, and entitled “Couplers for Use with Ducts of Concrete Segmental Construction”, presently pending. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
     Not applicable. 
     INCORPORATION-BY-REFERENCE OF MATERIALS SUBMITTED ON A COMPACT DISC 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the assembly and installation of precast concrete segments used in construction activities, such as bridge and highway construction. The present invention also relates to couplers for joining the ends of ducts of such precast concrete segments in end-to-end liquid-tight relationship. More particularly, the present invention relates to mandrels as used for fixing an angle of orientation of the ducts through the concrete segments. 
     2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98. 
     Precast segmental bridges are known and commonly used throughout the world as a means to forge roadways through mountainous terrain or across rivers or other barriers. Such bridges are typically constructed in accordance with the following sequence. First, a series of upright piers are formed along the bridge span. Thereafter, cantilevered bridge sections are built out of each pier by successively mounting the precast segments to previously completed bridge components and post-tensioning the segments thereto. The cantilevered bridge sections are built out from each pier in a symmetrical fashion so that the piers are not subjected to undue bending loads. When the cantilevered sections are complete, the ends thereof are post-tensioned together to form a continuous bridge deck. Typically, two such bridge spans are constructed to accommodate the two directions of travel. These spans are generally side-by-side, but need not be parallel (horizontally or vertically) nor at the same elevation. 
       FIGS. 1-4  illustrate a form of such precast segmental bridge construction in accordance with the teachings of U.S. Pat. No. 5,231,931, issued on Aug. 3, 1993 to G. Sauvagiot. This form of segmental precast bridge construction is particularly disclosed as used with a rapid transit viaduct system. 
     Referring to  FIG. 1 , a rapid transit viaduct section  2  includes a central load bearing span or body member  4  supported by a pair of upright pier members  6  and  8 . Extending laterally from opposite lower side portions of the central body  4  are a pair of lateral platform structures  10  and  12 . Each of the platform structures  10  and  12  has a pair of rails  14  mounted thereon for carrying a rapid transit vehicle. In addition, each of the platform sections may be provided with an upright sidewall section  16  as required for safety, noise pollution and other considerations. One or more sets of rails  14  are carried by each of the lateral platform structures  10  and  12  depending on the requirements of the transit systems. 
     The lateral platform structures  10  and  12  each include respective upper platform decks and respective lower support struts  22  and  24 . The lower support struts  22  and  24  are mounted as close to the bottom of the central load bearing body  4  as practicable. Deck members  18  and  20  are mounted to the central body  4  at an intermediate portion thereof above the support struts  22  and  24 . The support struts  22  and  24  angle upwardly from their point of attachment with the load bearing body  4  until they intersect the deck members  18  and  20 . As such, the deck members  18  and  20  and support struts  22  and  24  form a box section providing resistance to torsional loading caused by track curvature and differential train loading. This box section may be considered a closed base. The load bearing body  4  bisects the closed base and extends vertically upwardly therefrom to provide span-wise bending resistance. Preferably, the entire duct section  2  is cast as a single reinforced concrete cross-section. 
     The platform sections  10  and  12  each include lower pier mounts  26  and  28 . These are mounted respectively to the bottom of the support structures  22  and  24 . The pier mounts  26  and  28  are, in turn, supported, respectively, on the piers  6  and  8  using a plurality of neoprene pads  30 , which provide a cushioned support for the structure. 
     As shown in  FIG. 1 , the viaduct section  2  forms part of a viaduct system supporting rails  14  for carrying rapid transit vehicles  32  and  34 . The viaduct section  2  may be formed as a precast modular segment. The viaduct section  2  is then combined with other viaduct sections to form a precast segmental structure. To facilitate such construction, the load bearing body  4  may be formed with interlock member  36 , while the lateral platform structures  10  and  12  may be each formed with interlock members  38 . 
     Referring to  FIG. 2 , a viaduct system is formed from a plurality of precast sections  2  formed as modular segments and combined as a precast segmental structure extending between sequentially positioned piers (not shown). The sections  2  are placed in longitudinally abutting relationship. To facilitate that construction, the sections are match cast so that the abutting end portions thereof fit one another in an intimate interlocking relationship. Each successive section is therefor cast against a previously cast adjacent section to assure interface continuity. 
     The connection between adjacent modular sections  2  is further secured by way of the interlock members  36  and  38 . On one end of each section  2 , the interlock members  36  and  38  are formed as external keys. On the opposite end of each section  2 , the interlock members are formed as an internal slot or notch, corresponding to the key members of the adjacent viaduct system. Match casting assures that corresponding keys and slots, as well as the remaining interface surfaces, properly fit one another. 
     As seen in  FIG. 2 , the sections  2  are bound together with one or more post-tensioning cables or tendons  40 ,  42  and  44 . The number of cables used will depend on a number of factors such as cable thickness, span length and loading requirements. The tensioning cables are each routed along a predetermined path which varies in vertical or lateral position along the span of the segmental structure. 
       FIG. 3  illustrates, diagrammatically, the manner in which the post-tensioning cables  40 ,  42  and  44  extend through the concrete structure of the spans. As can be seen in  FIG. 3 , the post-tensioning cables are sometimes positioned within the concrete segment themselves, and at other times are positioned externally thereof. 
     It is important to note that multiple post-tension cables are often used as extending through ducts within the concrete structure. In  FIG. 4 , it can be seen that the sections  2  are formed with appropriate guide ducts  50  at locations where the post-tensioning cables pass through the structure. The post-tensioning cables identified collectively by reference numeral  52  in  FIG. 4 , are routed through the guide ducts  50 . To facilitate this routing, a continuous flexible conduit  54  is initially inserted through the guide ducts, and the post-tensioning cables  52  are thereafter placed in the conduit. The conduit  54  may advantageously be formed from polyethylene pipe but could also be formed from flexible metallic materials. The post-tensioning cables  52  are tensioned using a conventional post-tensioning apparatus, and the interior of the conduit  54  is cement grouted along the entire length thereof for corrosion protection. 
     One form of duct that is commercially available is shown in  FIG. 5 . The corrugated polymeric duct  56  is of a type presently manufactured by General Technologies, Inc., of Stafford, Tex., licensee of the present inventor. As can be seen in  FIG. 5 , duct  56  has a plurality of corrugations  58  extending radially outwardly from the generally tubular body  60 . The duct  56  has ends  62  and  64  through which post-tensioning cables can emerge. It can be seen that there are longitudinal channels  66 ,  68  and  70  extending along the outer surface of the tubular body  60 . The longitudinal channels  66 ,  68  and  70  allow any grout that is introduced into the interior of the duct  56  to flow easily and fully through the interior of the duct  56 . The longitudinal channels  66 ,  68  and  70  also add structural integrity to the length of the duct  56 . It is important to realize that the duct  56  can be formed of a suitable length so as to extend fully through one of the sections  2  as used in a precast segmental structure. 
     Unfortunately, when ducts, such as duct  56 , are used in such precast segmental construction, it is difficult to seal the ends  62  and  64  of each duct to the corresponding duct of an adjacent section of the segmental structure. Conventionally, the segments are joined together in end-to-end relationship through the application of an epoxy material to the matching surfaces of the structure. Under such circumstances, it is very common for the epoxy to flow or to become extruded into the opening at the ends  62  and  64  of the duct  56  when the segments are connected in end-to-end relationship. In other circumstances, a grout is pumped through the interior passageway of the duct  56  so as to offer a seal against the intrusion of air and water into the interior of the duct  56 . Unfortunately, if there is an incomplete connection between the duct  56  and the duct of an adjoining section of the segmental structure, then the grout will leak out into the interface area between the segments and will not flow fully through the entire duct assembly. Once again, an incomplete grouting of the interior of the duct  56  may occur. 
     It is important to note that in such precast concrete segmental construction, the concrete will slightly warp when matched with the adjoining section. Even though match casting is employed, the lack of homogeneity in the concrete mixtures used for the adjoining sections can cause a misalignment between matching sections. A great deal of tolerance must be maintained when a coupler is developed so that any warping or distortion in the surfaces of the matching segments can be accommodated. 
     The ability to avoid air and liquid intrusion into the interior of the duct  56  is very important in such multi-strand, precast concrete segmental structures. As can be seen in  FIG. 1 , since the structure is often used on bridges or elevated structures, the post-tensioning cables can be subject to a great deal of exposure from the elements. For example, if the bridge structure is associated with roads traveled by motor vehicles, then there is often the application of salt onto the highway. This salt, when dissolved in water, can leach through the area between the structure segments into the ducts and deteriorate the post-tensioning cables over time. As the post-tensioning cables become corroded, over time, they can weaken so as to potentially cause the failure of the segmental structure. Past experience with such structures has shown that the primary area of leakage would be through those cracks formed between those matched segments. As such, it is particularly important to provide a coupler for use in association with the plastic ducts which will effectively prevent any liquid intrusion from entering the area interior of the ducts and adjacent to the post-tensioning cables. 
     The present invention is the owner of several patents relating to duct couplers for use with precast concrete segmental construction. In particular, U.S. Pat. No. 6,764,105, issued on Jul. 20, 2004, describes a coupler member for use with precast concrete segmental structures. The structure is illustrated in  FIGS. 6 and 7  herein. Referring to  FIG. 6 , there is shown the precast concrete segmental structure  100  in accordance with the teachings of this patent. The structure  100  includes a first concrete segment  102  and a second concrete segment  104 . The first concrete segment  102  has an outer surface  106  which is joined in surface-to surface contact with the inner surface  108  of the concrete segment  104 . The segments  102  and  104  are formed by match casting, as described hereinbefore. 
     Importantly, a first duct  110  is embedded in the first concrete structure  102 . Duct  110  has a construction similar to that shown in  FIG. 5 , or similar to other multi-cable ducts. The first duct  110  has an end  112  generally adjacent to the outer surface  106  of the concrete segment  102 . Similarly, a second duct  114  is embedded in the second concrete segment  104 . The second duct  114  has a configuration similar to that of duct  110 . Duct  114  has an end  116  generally adjacent to the inner surface  108  of concrete segment  104 . Each of the ducts  110  and  114  are embedded in the respective concrete segments  102  and  104  so as to be generally longitudinally aligned. The duct  110  has an interior passageway which will be axially aligned with the interior passageway of duct  114 . 
     As can be seen in  FIG. 6 , a plurality of tendons  118  extend longitudinally through the interior passageways of the ducts  110  and  114 . In  FIG. 6 , these tendons  118  are properly post-tensioned in a conventional manner. A grouting material  120  is introduced through the interior passageways  110  and  114  to further cement and seal the interior of the ducts  110  and  114  around the tendons  118 . The grouting material, in combination with the polymeric material of the ducts  110  and  114 , serves to avoid the adverse effects of liquid intrusion into the tendons  118 . A unique coupler apparatus  122  further assures the avoidance of liquid intrusion through the space between the outer surface  106  of concrete segment  102  and the inner surface  108  of concrete segment  104 . A first coupler member  124  extends over and around the exterior surface of the first duct  110 . The first coupler member  124  has an end  126  opening at the outer surface  106  of concrete segment  102 . Similarly, the end  126  of the coupler member  124  is generally forward of, but adjacent to, the end  112  of first duct  110 . A second coupler member  128  extends over and around the exterior surface of the second duct  114 . The second coupler member  128  has an end  130  opening at the inner surface  108  of concrete segment  104 . End  130  is slightly forward of the end  116  of the duct  114 . A gasket  132  is received in the ends  126  and  130  of the respective coupler members  124  and  128 . The gasket  132  is particularly designed to prevent liquid from passing between the ends  126  and  130  of the respective coupler members  124  and  128  into the interior of the ducts  110  and  114 . The coupler members  124  and  128  have an identical configuration to each other. This serves to minimize the manufacturing requirements since only a single mold is required for each of the coupler members. Also, installation is easy since unskilled workers can install the first and second coupler members  124  and  128  without regard to the configuration of a particular coupler member. 
     An external seal  134  is affixed in generally liquid-tight relationship to an opposite end  136  of the first coupler member  124  and is also affixed to an exterior surface of the first duct  110 . In particular, the external seal  134  is formed of an elastomeric sleeve or an annular heat shrink material. The external seal  134  will be in compressive liquid-tight contact with the exterior surface of the first coupler member  124  and with the exterior surface of the duct  110 . Prior to embedding the coupler member  124  into the concrete associated with the concrete segment  102 , the coupler member  124  can be affixed in liquid-tight relationship by applying heat to the exterior surface of the external seal  134 . As a result, the heat-shrink material of the external seal  134  will tightly engage the surfaces of the coupler member  124  and also the exterior surfaces of the duct  110 . As a result, the external seal  134  will prevent liquid intrusion through the opposite end  136  of the coupler member  124 . 
     An internal seal  138  is interposed in generally liquid-tight relationship between the interior surface of the second coupler member  128  and the exterior surface of the second duct  114 . This internal seal  138  is a generally annular ring formed of an elastomeric material. The internal seal  138  is positioned to allow relative movement between the second coupler member  128  and the second duct  114  while maintaining the liquid-tight relationship between the coupler member  128  and the duct  114 . The ability to allow relative movement between the coupler member  128  and the duct  114  is important because of the “match casting” used for the formation of the second concrete segment  104 . If there is any warping or inconsistent relationship between the surfaces  106  and  108 , the second coupler member  128  will be able to relatively move with respect to the exterior surfaces of the duct  114  to adjust for such warping or inconsistencies. The second coupler member  128  is also movable in relation to any expansion or contraction of the concrete segments  102  and  104 . This can be done without affecting the liquid-tight environment between the coupler member  128  and the duct  114 . 
     In  FIG. 6 , it can be seen that the end  126  of the first coupler member  124  has a generally V-shaped groove facing the second coupler member  128 . In particular, it is the opening of this V-shaped groove which faces the second coupler member  128 . Similarly, the end  130  of the second coupler member  128  has a V-shaped groove which faces the V-shaped groove of the end  126 . It can be seen that the gasket  132  is fitted into the V-shaped groove at one of the ends  126  and  130  or into both of the ends  126  and  130 . 
     So as to further assure the avoidance of any liquid intrusion, it can be seen that the end  126  of the first coupler member  124  has a surface  140  which is in abutment with the end  112  of the first duct  110 . Similarly, the, second coupler member  128  has a surface  142  which is in abutment with the end  116  of the second duct  114 . This relationship further assures the accurate placement of the coupler members in end-to-end relationship and further assures the alignment of the ducts  110  and  114 . 
     As can be seen in  FIG. 6 , the gasket  132  is an elastomeric ring having a cross-sectional thickness greater than a depth of either of the V-shaped grooves of the respective ends  126  and  130  of the coupler members  124  and  128 . As a result, the elastomeric ring of the gasket  132  will effectively “fill” the outer portions of the V-shaped grooves. The configuration of the V-shaped grooves causes the elastomeric material of the gasket  132  to “extrude” thereinto so as to establish a tight sealing relationship therewith. 
     The first duct  110 , the second duct  114 , the first coupler member  124  and the second coupler member  128  are each formed of a polymeric material. Each of these components can be formed in an injection molding process. Similarly, the gasket  132  can be formed of an elastomeric or other resilient material. The material used for the gasket  132  should be suitably hydrophobic so as to resist any liquid intrusion. 
       FIG. 7  is an illustration of the apparatus  100  prior to the installation of the tendons  118  and the installation of the grout  120 . The first duct  110  is suitably mounted against a metal bulkhead having a flat surface corresponding to the formation of the outer surface  106  of concrete segment  102 . A suitable fixture is provided on the metal bulkhead which will extend into the interior  160  of the first duct  110 . Prior to the installation of the first duct  110  onto the bulkhead fixture, the coupler member  124  is placed over the exterior surface of the first duct  110 . Similarly, the external seal  134  is placed over the end  162  of the coupler member  124  opposite the end  126 . A suitable heating device, such as a hot air blower, can be applied to the external seal  134  so as to heat shrink the seal  134  upon the exterior surface of the duct  110  and upon the exterior surface of the first coupler member  124 . Once the duct  110 , along with the attached coupler member  124 , is placed upon the bulkhead fixture, the concrete  164  can then be poured into a suitable mold. After solidifying, the metal bulkhead and the attached bulkhead fixture are removed from the surface  106  so as to create a flat surface thereagainst. Upon solidification, the inner surface  108  of the concrete segment  104  will be formed by match casting. In other words, the surface  106  will act as a surface for the formation of surface  108 . A suitable mandrel or alignment plug can be placed into the interior passageway  160  of the first duct  110 . This alignment plug can extend outwardly beyond the surface  106 . The second coupler member  128  can then be applied onto the exterior surface of the second duct  114 . The internal seal  138  is interposed between the inner surface of the second coupler member  128  and the exterior surface of the duct  114 . The second duct  114  and its associated coupler  128  can then be placed over the alignment plug extending outwardly of the interior passageway  160  of the duct  110  so as to extend into the interior passageway  166  of the second duct  114 . Since there is a possibility of slight misalignment during the formation of the second concrete segment  104 , the second coupler member  128  is slidable relative to the duct  114  by virtue of the “rollability” of the internal seal  138 . 
     After the concrete solidifies, the surface  108  will be separated from surface  106 . Similarly, the end  130  of the coupler member  128  will be separated from the end  126  of the coupler  124 . The gasket  132  can then be installed into the V-shaped groove associated with the end  130  of the second coupler  128 . Because of the enlarged cross-sectional area of the annular gasket  132 , a portion of the gasket  132  will extend outwardly beyond the end  130  of the second coupler member  128 . 
     The segment  102  can then be installed as part of the segmental structure. The segment  104  is then transported into position so that the surface  108  will face the surface  106 . Since it is possible that a misalignment of the surface of the segments can occur, the particular arrangement of the V-shaped grooves and the shape of the gasket  132  will accommodate any misalignment. When the surface  108  is brought into proximity against the surface  106 , the relatively pointed side  168  of the gasket  132  will “funnel” into the V-shaped groove  170  at the end  126  of the first coupler member  124 . Particularly, the pointed side  168  may contact either of the sides  172  or  174  of the V-shaped groove  170 . As the surface  108  is brought further into proximity with surface  106 , the gasket  132  will extrude into the V-shaped groove  170  so as to establish an effective liquid-tight seal therewith. After assembling and epoxying of the surfaces  106  and  108  together, tendons can be extended through the interior passageways  160  and  166  of the respective ducts  110  and  114  so as to permanently join the segments  102  and  104  in post-tensioned relationship. 
     Importantly, as can be seen in  FIG. 6 , the use of the unique configuration of the gasket  132 , along with V-shaped groove  170 , will avoid any intrusion of epoxy into the interior passageways  160  and  166 . The gasket  132  will block the extruded epoxy from flowing in an undesired manner into the interior passageways  160  and  166 . In a similar manner, the gasket  132  will also prevent any liquid intrusion from passing into these interior passageways  160  and  166 . The compressive relationship between the V-shaped grooves associated with the coupler members  124  and  128  establishes a strong sealing bond between the coupler members which will be resistive to the elements over an extended period of time. Subsequent to installation, the grout can be effectively pumped through the interior passageways  160  and  166  without any grout accidentally flowing outwardly of the ducts  110  and  114  in the area of the space between the segments  102  and  104 . Secondary liquid intrusion is effectively accomplished through the tight sealing relationship of the external seal  134  and the sliding sealing of the internal seal  138 . 
     U.S. Pat. Nos. 6,764,105, 6,834,890 and 6,874,821 show variations on this prior invention. In particular, U.S. Pat. No. 6,764,105, issued on Jul. 20, 2004 to the present inventor, teaches a coupler member for use with precast concrete segmental structures. This coupler member has a first duct, a first coupler member extending over and around an exterior surface of the first duct and having a seat opening adjacent an end of the first duct, a second duct, a second coupler member extending over and around an exterior surface of the second duct and a seat opening adjacent to an end of the second duct. A gasket is received in the seats of the first and second coupler members. An external seal is affixed to an opposite end of the first coupler member and affixed to an exterior surface of the first duct. The seats of the first and second coupler members have slots facing one another. The gasket is received within these slots. The gasket has a tapered outer surface suitable for liquid-tight abutment against an inner surface of one of the slots. 
     U.S. Pat. No. 6,834,890, issued on Dec. 28, 2004 to the present inventor, describes another coupler apparatus for use with tendon-receiving ducts in a segmental precast concrete structure. This coupler apparatus includes a coupler body having an interior passageway for receiving the duct therein. The coupler body has a generally U-shaped channel formed at one end thereof. The coupler element has a connector element formed on interior thereof adjacent one end of the coupler body so as to allow the coupler element to receive a variety of implements for the formation of the precast concrete segment. 
     One of the problems associated with these prior art patents is that each of these prior art patents is particularly designed where the tendons are maintained in generally longitudinal alignment. However, in precast concrete construction, the edges of the concrete segments will be aligned with each other while the ducts extend at an angle with respect to these edges. As such, it is necessary for the coupler apparatus to be able to accommodate the angled relationship of the ducts. Since each of the coupler segments must open at an end of the concrete structure and be joined together at such end, the coupler apparatus must be able to accommodate the fact that the ducts extend at an angle with respect to these ends. As such, U.S. Pat. No. 6,874,821, issued on Apr. 5, 2005 to the present inventor, was designed to accommodate this angled relationship of the ducts. This patent describes a coupler apparatus for use with precast concrete segmental construction. The coupler apparatus has a first duct, a first coupler member extending over and around the first duct, a second duct, a second coupler member extending over and around the second duct, and a gasket received at the ends of the first and second coupler members so as to prevent liquid from passing between the coupler members into an interior of either of the ducts. The ducts extend at a non-transverse acute angle with respect to the ends of the coupler members. Heat shrink seals are affixed to the opposite ends of the coupler members so as to secure the coupler members to the ducts in liquid-tight relationship. The ends of the coupler members have generally V-shaped grooves facing each other. The gasket is received in compressive relationship within the V-shaped grooves. 
     Although the device shown in U.S. Pat. No. 6,874,821 is effective for connecting angled post-tension cables in precast concrete segmental construction, it is believed important to be able to flexibly arrange the positioning of the ducts with respect to the coupler members. As such, a need developed so as to provide a structure whereby the angled relationship of the ducts can be easily and effectively achieved through the use of standard coupler constructions. So as to achieve a properly angled relationship, it is very important that the angle with which the duct extends in one concrete segment be identical to the angle that the duct extends through adjoining segments. It is found (with existing segmental concrete construction practices) that the angle of a duct in an adjoining section may slightly vary from the angle with which another duct extends in the other concrete segment. As such, a need has developed whereby the concrete segments are orientated at an identical angle in each segment. 
     It is an object of the present invention to provide an apparatus which allows for the coupling of multi-tendon ducts in precast segmental concrete structures. 
     It is another object of the present invention to provide an apparatus which automatically adjusts for any misalignments or warpage in the matching concrete segments. 
     It is another object of the present invention to provide an apparatus which assures a seal between the coupler and the connected duct. 
     It is still a further object of the present invention to provide an apparatus which is easy to install, easy to use and easy to manufacture. 
     It is still a further object of the present invention to provide an apparatus which effectively prevents the intrusion of an epoxy into the interior of the duct during the sealing of one structural segment to another structural segment. 
     It is still a further object of the present invention to provide an apparatus which is universally adaptable between ducts that extend transverse to the edges of the segmental construction to those ducts that extend at an angle with respect to edge of the concrete structure. 
     It is still a further object of the present invention to provide an apparatus that flexibly allows the ducts to move longitudinally toward or away from each other within the concrete structure. 
     It is still a further object of the present invention to provide an apparatus that assures that the duct of one concrete segment extends at an identical angle with respect to the duct of an adjacent concrete segment. 
     These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is an apparatus for fixing an orientation of a duct in concrete segmental construction comprising an elongate body, a frame having an inner surface facing the elongated body, and an angle adjusting means connecting the inner surface of the frame to the elongated body. The frame has means thereon for connecting to a bulkhead. The elongated body is orientatable relative to the frame by way of the angle adjusting means. The elongated body has a slotted end. The slotted end receives a surface of the angle adjusting means therein. In particular, the elongated body is a tubular member having a diameter in surface-to-surface contact with an inner wall of the duct. The angle adjusting means of the present invention includes a pin extending through the frame, a ball mounted on the pin, and a flange affixed to the ball. The flange is in surface-to-surface contact with an end of the elongated body. The pin is operably connected to the ball so as to fix an orientation of the flange. The frame has a generally U-shape. The angle adjusting means is positioned generally centrally between opposite sides of the frame. 
     The present invention is also a system for use in concrete segmental construction comprising a duct, a bulkhead having an opening facing an end of the duct, an elongated body extending through the interior of the duct, a frame affixed over the opening of the bulkhead, and a angle adjusting means connecting the frame to the elongated body. The angle adjusting means is suitable for orienting the elongated body at a desired angle with respect to the frame. 
     A boot is affixed over an exterior of the duct. A connector section is connected to the end of the boot opposite the duct. This connector section is juxtaposed against a surface of the bulkhead. The frame is removably affixed to an interior of the connector section. 
     The frame has an end wall and a side wall in transverse relation to the end wall. The angle adjusting means is affixed to the end wall. The side wall has a groove formed therein. This groove is in snap-fit relation with a protrusion on the interior of the connector section. 
     The elongated body has a slotted end. The slotted end receives a surface of the angle adjusting means therein. The elongated body is a tubular member having a diameter in surface-to-surface contact with the inner wall of the duct. The angle adjusting means includes a pin extending through the frame, a ball mounted on the pin, and a flange affixed to the ball so as to be in surface-to-surface contact with an end of the elongated body. The pin is operably connected to the ball so as to fix an orientation of the flange. The elongated body extends at an acute angle relative to the bulkhead. 
     A concrete material surrounds an exterior surface of the duct and is juxtaposed against a surface of the bulkhead. 
     The present invention is further a mandrel system for use in concrete segmental construction. This mandrel system comprises a first concrete segment having an end surface, a first duct extending at an acute angle with respect to the end surface and having a connector opening at this end surface, a first mandrel extending through an interior of the first duct and having an end facing outwardly of the connector at the end surface, a second duct having a connector juxtaposed against the connector of the first duct, and a second mandrel having an end juxtaposed against the end of the first mandrel. The second mandrel extends through an interior of the second duct. The second mandrel is longitudinally aligned with the first mandrel. 
     A plug is affixed to an inner surface of the connector of the first duct and to an inner surface of the connector of the second duct. The plug has an interior with a diameter greater than an outer diameter of the first and second mandrels. The first and second mandrels extend through the interior of the plug. The first duct has a boot with a surface at one end extending over an exterior of the first duct. The connector of the first duct is positioned at an opposite end of the boot. The second duct has a boot with a surface at one end extending over an exterior of the second duct. The connector of the second duct is positioned at an opposite end of the boot. A bulkhead is positioned at an opposite end of the second mandrel. This bulkhead has an opening facing an end of the second duct opposite the first duct. A frame is affixed over the opening of the bulkhead. A ball joint connects the frame to the second mandrel. This ball joint orients the second mandrel at an angle identical to the acute angle of the first duct. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a diagrammatic view showing a cross-section of a rapid transit viaduct structure employing a prior art precast segmental structure. 
         FIG. 2  is a partially diagrammatic view showing a cross-section indicating the assemblage of the concrete segments of the structure of  FIG. 1  and showing, in particular, the alignment of the post-tensioning cables. 
         FIG. 3  is an end view of a precast concrete segment, and the associated post-tension cables, of the prior art structure if  FIG. 1 . 
         FIG. 4  is a diagrammatic cross-sectional view showing the prior art techniques for the routing of a cable through the duct associated with the concrete segment. 
         FIG. 5  is a side elevational view of a prior art multi-cable duct as used in the present invention. 
         FIG. 6  is a cross-sectional view showing the coupler assembly as used in a precast concrete segmental structure of the prior art. 
         FIG. 7  is a cross-sectional view showing the assembly of the coupler apparatus of the prior art of  FIG. 6 . 
         FIG. 8  is a side elevational view and partial cross-section of the coupler apparatus as used in the mandrel system of the present invention. 
         FIG. 9  is a side elevational view, in partial cross-section, of the coupler assembly as used in the mandrel system of the of the present invention. 
         FIG. 10  is a cross-sectional view showing the placement of the mandrel system of the present invention within a duct. 
         FIG. 11  is a cross-sectional view showing the mandrel system of the present invention for the alignment of ducts within segmental concrete construction. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 8 , there is shown the coupler apparatus  200  as used in the mandrel system of the present invention. The coupler apparatus  200  includes a duct  202  having a flexible boot  203  connected over an end  206  thereof. A clamp  204  is placed around the outer diameter of the flexible boot  203  and over the outer diameter of the duct  202  so as to secure the end of the flexible boot  203  in liquid-tight sealing relationship against the ridges  208  of the duct  202 . The flexible boot  203  has an annular section  210  connected to an end of the flexible boot  203  opposite the duct  202 . The annular section  210  includes an annular groove  212  formed outwardly thereof. The annular groove  212  defines an interior passageway  214  therein. Interior passageway  214  is aligned with the interior passageway  216  of the duct  202 . 
     As can be seen in  FIG. 8 , the flexible boot  203  can be folded upon itself so that the duct  202  is in linearly-aligned relationship with the annular section  210  and with the annular groove  212 . Additionally, the flexible boot  203  can be folded upon itself so as to allow the duct  202  to move longitudinally with respect to the position of the annular section  212 . 
     The clamp  204  is also an annular surface that has an inner surface juxtaposed against the exterior surface of the end  218  of the flexible boot  203 . In normal use, this “clamp means” can include various structures that serve to establish a strong compressive contact between the inner surface of the flexible boot  203  and the exterior surface of the ridges  208  of duct  202 . For example, a lever-type mechanism can be incorporated into the structure of the clamp  204  so as to create this compressive contact. In other circumstances, the clamp  204  can be in the nature of a band of heat-shrink material. When heat is applied to the heat-shrink material, it will establish a strong bonding relationship over of the exterior surface of the end  218  of the flexible boot  203  while, at the same time, creating the requisite compressive contact between the inner surface of the end  218  of boot  203  and the exterior surfaces of the ridges  208  of the duct  202 . Other types of mechanisms, such as retracting clamps, threaded braces, and other devices can be utilized in association with the boot  203  so as to establish the “clamping means”. 
     The opposite end  220  of the flexible boot  203  is fixed secured to the annular section  210 . The annular groove  212  extends radially outwardly of the annular section  210  and also longitudinally outwardly of the end  220  of the flexible boot  203 . In normal use, and as will be described hereinafter, the annular groove  212  will receive a gasketing material therein. The annular groove  212  will face a matching outer wall of the concrete segment. 
       FIG. 9  shows the coupler assembly  230  of the present invention. As can be seen, the coupler assembly  230  includes a first coupler apparatus  232  affixed over the exterior surface of a first duct  234  and a second coupler apparatus  236  secured over the exterior surface of the second duct  238 . The first coupler apparatus  232  includes a boot  240  that has an end  242  in compressive sealing contact against the outer surface of one of the ridges  244  of the first duct  234 . A suitable clamping means  246  is used so as to establish this strong compressive contact. 
     The boot  240  is shown as having one side  248  that is folded upon itself while the opposite side  250  extends outwardly. This allows the annular section  252  to be extended at an angle in relationship to the longitudinal axis of the duct  234 . The annular groove  254  faces outwardly of the annular section  252 . 
     The second coupler apparatus  236  also includes a flexible boot  256  that is connected at one end to an annular section  258 . A clamp  260  is utilized so as to establish a strong sealing relationship between the end  262  of the flexible boot  256  and the outer surface of one of the ridges  264  of the duct  238 . As such, the second coupler apparatus  236  has an identical configuration to that of the first coupler apparatus  232 . The boot  256  has one side that is folded upon itself while the other side is fully extended. As such, the annular groove  266  of the annular section  258  of the second coupler apparatus  236  directly faces the annular groove  254  of the annular section  252  of the first coupler apparatus  232 . In the configuration illustrated in  FIG. 9 , the coupler assembly  230  is particularly configured for use in which the tendons of the segmental concrete structure are intended to be extended at an angle with respect to the edges of the concrete structure. 
     Referring to  FIG. 10 , there is shown the mandrel system  300  for use with the ducts of segmental concrete construction. In  FIG. 10 , the mandrel system  300  includes an elongated body  302 , a frame  304 , and an angle adjusting means  382 . In  FIG. 10 , the angle adjusting means  382  is a ball joint  306 . The elongated body  302  is received on the ball joint  306  so as to allow for the desired angular orientation of the elongated body  302 . 
     The elongated body  302  is a tubular member that has an outer diameter that resides in surface-to-surface contact with the inner wall of the duct  308 . Duct  308  has a configuration similar to the duct of the previous embodiment. The elongated body  302  has an end  310  with a slot  312  formed therein. The ball  314  of ball joint  306  has a surface that is received within this slotted area  312  at end  310 . As can be seen in  FIG. 10 , the mandrel  312  is oriented at approximately 15° from transverse to the wall  316  of bulkhead  318 . 
     It can be seen that the frame  304  has a generally U-shaped cross section. In particular, the frame  304  includes side walls  320  which extend transverse to the end wall  322 . The side walls  320  of the frame  304  are affixed over an opening in the bulkhead  318 . In particular, the outer surface of the side walls  320  includes a shouldered portion  324  which resides against the outer surface  326  of bulkhead  318 . As such, the frame  304  is fixed in position over this opening in the bulkhead  318 . The sidewalls  320  of frame  304  extend inwardly into the opening in the bulkhead  318  so as to have a portion that engages with an inner surface  328  of the connector section  330  of the boot  332  associated with duct  308 . In particular, there is a groove  334  which is in snap-fit relationship over a protrusion  336  formed on the inner wall of the surface  328  of connector section  330 . In this manner, the frame  304  properly snap-fits into an accurate position onto the bulkhead  318  and onto the connection section  330  associated with duct  308 . As such, the frame  304  will assume a very fixed position with respect to the concrete section. 
     The bulkhead  318  is in the nature of a form board used in the formation of the concrete segment. The inner surface  316  of bulkhead  318  will be flat so as to form the end surface of the concrete segment. The bulkhead  318  is removable from this end surface of the concrete after the end surface is properly formed. When the bulkhead  318  is removed, the frame  304  can be released from its engagement with the protrusion  336  of the connector section  330 . As such, the bulkhead  318  and the frame  304  can be used on the opposite end of the next concrete segment. 
     The ball joint  306  includes a pin  338  which extends through the end wall  322  of the frame  304 . Pin  338  is connected to the ball  314 . A flange  340  extends outwardly from the ball  314  so as to be in surface-to-surface contact with the end surface  342  of the elongated body  302 . As such, the surface of the ball  314  will be seated within the slotted area  312  while, at the same time, the end surface  342  will be in surface-to-surface contact with the flange  340 . The pin  338  can be suitably tightened so as to cause the ball  314  to be drawn within seat  344  and, thus, the position of the ball  314  and the flange  340  to be fixedly positioned. This fixed position of the ball  314  and flange  340  can be established prior to the installation of the mandrel system  300 . For example, if the engineered design engineers shows that the duct  308  should extend at an angle of 15° from transverse with respect to the end surface of the concrete segment, then the orientation of the flange  340  can be set at 15° with respect to the end surface of the concrete segment. As such, the desired orientation of the duct  308  can be properly achieved. Once the ball  314  and the flange  340  are in a fixed position, the mandrel system  300  can continue to be used on subsequent segments associated with the segmental concrete construction. 
     In  FIG. 10 , it can be seen that the boot  312  has an end  346  which overlies the outer surface of the duct  308 . A suitable clamping means  348  can be applied over the outer surface of the end  346  of boot  332  so as to fix a position of this end  346  of boot  332  over the duct  308 . The connector section  330  is placed so that the seal-retaining groove  380  faces the surface  316  of the bulkhead  318 . As was described herein previously, the surface of the boot  332  is suitably flexible so as to allow for this angular formation of the duct  308 . 
     When the concrete segment is formed within the interior of the bulkhead  318 , the bulkhead  318  and its associated frame  304  will cause the ball  314  to separate from the slotted area  312  and the flange  340  to be separate from the end surface  342  of elongated body  302 . When this occurs, the next concrete segment is in a suitable condition for preparation. 
       FIG. 11  illustrates the mandrel system  300  of the present invention as applied in association with a subsequent concrete segment. In  FIG. 11 , it can be seen that concrete segment  350  has solidified and defines an end surface  352 . The connector section  330  faces so as to open at the end surface  352 . The elongated body  302  serves as the first mandrel in the system  300  of the present invention. Since the ball  314  has been separated from the end  310  of elongated body  302 , a flat surface  342  is presented for abutment with an end surface  354  of second mandrel  356 . It can be seen in  FIG. 11  that the elongated body  302  (the first mandrel) extends in longitudinal alignment with the second mandrel  356 . As such, the proper orientation of the duct  308  with duct  358  can be achieved. 
     In particular, it can be seen that the second mandrel  356  extends through the interior of the second duct  358 . The second duct  358  includes a boot  360  that has a connector section  362  at one end thereof. The opposite end of boot  360  is secured by a clamp  364  onto the exterior surface of the duct  358 . The end  366  of the connector section  362  is placed in juxtaposition against the end surface  368  of connector section  330 . 
     In  FIG. 11 , the protrusion  336  of the inner surface  328  of connector section  330  is received within a groove  370  in a plug  372 . Similarly, a protrusion  373  on the inner surface  374  of connector section  362  is received by the indentation  376  formed at another position on the outside surface of the plug  372 . As such, the plug  372  assures the proper fixed positioning of the connection sections  330  and  362  of the respective ducts  308  and  358 . The plug  372  has a inner diameter that is greater than the outer diameter of either of the elongated body  302  or the second mandrel  356 . As such, plug  372  can accommodate the angled relationship of the mandrel  302  and  356  within the concrete. Suitable seals, as described hereinbefore, can be placed within the open interiors of the respective connector sections  330  and  362  so as to establish a liquid-tight seal therebetween. 
     In  FIG. 11 , it is important to note that the positioning system associated with the frame  304 , the bulkhead  318 , and the ball joint  306  is achieved by proper placement within the interior of the second mandrel  356  at the opposite end of the mandrel  356 . The concrete segment into which the second duct  358  is positioned can be formed by match casting with the outer surface  352  of concrete segment  350 . As such, the mandrel system  300  of the present invention achieves the proper angled relationship between the ducts  308  and  358 . Furthermore, the unique configuration of the boots  332  and  360  allows the connector section  330  and  362 , respectively, to achieve the proper face-to-face relationship despite the angled orientation of the respective ducts. Through the use of the mandrel system of the present invention the proper angled relationship of the ducts is properly achieved. After the concrete segments are formed, the mandrels  302  and  356  can be removed. After removal, suitable tendons can be pushed through the interior of the ducts in the desired angled relationship. Any liquid intrusion through the facing surfaces of the concrete segments is avoided through the use of the connector sections and their appropriate seals. 
     The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction can be made within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.