US 3691708 A
A fluidtight seal connection for a pair of precast concrete structural panels having opposed recesses on their confronting surfaces includes an elongated locking channel disposed within one of the confronting recesses and a pliable one-piece sealing strip supportably retained within the locking channel for cooperative sealing action with the confronting recess. The elongated sealing strip includes a triangular central body portion traversing the opening of the channel, a flexible and deformable tubular fluid barrier integral with the central body portion for deformably sealing the joint between the panels and an anchoring member depending from the central body portion of the strip and extending into the channel for lockable retention of the strip therein.
Claims available in
Description (OCR text may contain errors)
[451 Sept. 19,1972
United States Patent Firnkas 154] WATERTIGHT SEAL CONNECTION 1,452,891 8/1966 France.........................52/393 FOR PREFABRICATED BUILDING 39,769 6/ 1965 East Germany 94/ l 8 PANEL SEAMS 1 ,268,347 5/1968 Germany.....................52/396  Inventor:
Sepp Firnkas, Boston, Mass. Primary Examiner-Frank L. Abbott  Assignee: Ommform Incorporated, Hartford, Assistant Examine, Hem-y Raduazo Conn.
Attorney-Prutzman, Hayes, Kalb & Chilton  Filed: April 15, 1970 ABSTRACT A fluidtight seal connection fora pair of precast  Appl. No.: 28,692
concrete structural panels having opposed recesses on their confronting surfaces includes an elongated locking channel disposed within one of the confronting recesses and a pliable one-piece sealing strip supportably retained within the locking channel for cooperative sealing action with the confronting recess. The elongated sealing strip includes a triangular central body portion traversing the opening of the chanw o 2MU42M fl 6 3 5 3 98? 3 3200 10E 91 4 $35, R 698. 2 5, 25 R W22% 2 Q 9 E76 2 "29 5 "23 w my ,2 m 3mm m 1 n 3 i u u 72 u h 7 "N5 u 3 m mm n Fm C GM.) s no U IF  References Cited UNITED STATES PATENTS nel, a flexible and deformable tubular fluid barrier integral with the central body portion for deformably 2,717,514 9/1955 Sealing the joint between the Panels and an anchoring 2,932,964 4/1960 Dobell........................ member depending from the central body portion of 2,986,848 6/1961 Greene..., the strip and extending into the channel for lockable 3,002,322 10/1961 Dorsett....................... retention of the strip therein. 3,364,641 1/1968 Brenneman 4 Claims, 2 Drawing Figures FOREIGN PATENTS OR APPLICATIONS 1,363,938 5/1964 France........................
PAIENTEBssm mm 3.691, 708
sum 1 or 2 INVEN R SEPP NKAS ATTORNEYS WATERTIGIIT SEAL CONNECTION FOR PREFABRICATED BUILDING PANEL SEAMS BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates generally to prefabricated building systems and is more particularly directed to a new and improved watertight connection for use at the seams or joints of prefabricated building umts.
Interest in prefabricated building units has grown steadily over the past few years, particularly for low cost, multi-family dwellings. Such units frequently employ precast concrete elements for both the wall panels and floor slabs requiring that considerable-attention be given to the various ways and means of interlockably securing the panels and slabs to provide the requisite structural continuity. A stacked method of construction which relies primarily on gravity and bond connections and requires in situ concrete has been extensively employed, particularly in Europe, but such'structures lack the necessary structural ductility and resistance to lateral loads frequently caused by seismic forces such as earthquakes or differential settlement of the footings. Additionally, the stacked method requires synchronized scheduling of two different construction operations and is dependent on the existence of satisfactory weather conditions.
In accordance with my development an active dry connection is used not only to impart definite and controlled stresses to the building joint and allow variation in joint strength depending on the intensity of lateral loads, but also to advantageously provide a fluidtight seam or joint between prefabricated elements despite tolerance variations in the elements. Included in this construction is the provision for a quasi-monolithic structure having at least two paths of load transfer through the modular precast elements and an ability to resist loads resulting from earthquakes, differential settling or the like.
Accordingly, an object of the present invention is to provide a watertight seal connection for precast concrete structural panels which eliminates the necessity of grouting, caulking or other conventional waterproofing techniques, yet at the same time provides a highly effective, durable, and corrosion resistant barrier to leakage of water through the joints formed by the precast concrete elements.
Another object of the present invention is to provide an active dry connection of the type described which permits tolerance variations within the precast elements yet at the same time prevents compounding of the tolerance variations over the total structural unit and compensates for these variations at each floor level of the building unit. In addition, the fluidtight connection combines a failsafe feature imparting to the complete structure a ductility which is equal or exceeds that of a steel frame without causing cracking of the concrete elements or exceeding the yield strength of the post-tensioned steel extending through the buildmg.
Still another object of the present invention is to provide a connection of the type described which provides a firm, abutting surface for solidly compacting the mortar within the open joint and permits the dry placement of all elements and the positive clamping of the floor slabs between load bearing wall panels to create a semirigid restraint and thus structural continuity throughout the building.
It is a further object of the present invention to provide an extremely durable and highly effective connection of the type described in a rapid, facile and economical manner without sacrificing structural strength or incorporating erection disadvantages.
Other objects will be in part obvious and in part pointed out in more detail hereinafter.
These and related objects are accomplished in accordance with the present invention by providing afluidtight seal connection comprising a pair of aligned structural panels in edgewise confronting relationship having opposed recesses on their confronting surfaces,
one of said recesses including an elongated locking channel, and a pliable one-piece sealing strip supportably retained within. the locking channel for cooperative sealing action with the confronting recesses. The elongated sealing strip includes a central body portion traversing the opening of the channeLa flexible and deformable fluid barrier integral with the central body portion for deformably sealing the joint between the panels and an anchoring member depending from the central body portion of the strip and extending into the channel for lockable retention of the strip therein.
A better understanding of the objects, advantages, features, properties and relationships of the invention will be obtained from the following detailed description and accompanying drawings which set forth an illustrative embodiment indicative of the way in which the principle of the invention is employed.
BRIEF DESCRIPTION OF THE DRAWINGS v In the drawings:
FIG. 1 is an exploded perspective view, partially in section, of a fluidtight connection incorporating the features of the present invention; and
FIG. 2 is an enlarged sectional view of the connection of FIG. 1 in its fully assembled condition.
DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawings in greater detail wherein like referenced numerals indicate like parts throughout the figures, the invention is illustrated as embodied within a horizontal joint or seam formed by a pair of vertically disposed bearing wall panels 12 and I4 and one edge of a floor slab I6 confmably secured therebetween. Each of these prefabricated elements can be of modular precast concrete construction and because of the advantageous features of the present invention need not be formed to meet high tolerance levels but may vary in dimensions.
The structural wall panels 12 and 14 need not be identical in construction, but for ease of description and clarity of understanding, they will be hereinafter discussed as if they were identical. The panels 12 and 14 are disposed in aligned overlying relationship with their peripheral top and bottom surfaces 20 and 18, respectively, mated in face-to-face confronting relationship. The surfaces 18, 20 are provided with complementary recesses 22, 24, respectively, spaced from the exterior or exposed face 26 of the panels and extending along the full length of their respective surfaces. in the particular embodiment chosen for illustrative purposes, the upper wall panel 12 is shown with an inwardly tapered recess 22 of truncated triangular cross section while the lower wall panel 14 is provided with a much narrower recess 24. As shown, the recess 24 supports a locking channel member 32 of h-shaped cross section embedded within the lower wall panel 14. As will be appreciated, complementary side recesses (not shown) are also provided in each panel to effect the requisite vertical seam connection of the panels.
Each wall panel is further provided with a plurality of parallel, vertically disposed passages 34 extending through the panels in substantial alignment. Post-tensioning rods or tendons 36 for resisting the various loads are anchored in the foundation of the building unit and pass continuously through the passages 34in each overlying panel until they reach the eaves of the building. The tendons 36 are preferably equal in length to the height of the individual panels and extend fully therethrough from an anchoring position below the panel. They are threaded on their ends, as shown at 38, both for ready connection with an axially extending tendon and for retention in their tensioned condition by a suitable lock-nut arrangement.
In order to provide easy access for the connection, the top edge of each panel is provided with an enlarged inwardly facing shoulder 42 slightly greater in depth than the thickness of the floor slab l6 confinably supported thereon. A flat, generally rectangular locking plate 46 precast within the panel 14 forms a portion of the shoulder 42 through which the passages 34 extend and firmly supports a locking beam 48 against which the lock-nut 50 acts in securing the tendons 36 after tensioning thereof. The threaded end portions 38 of the tendons 36 also threadably receive a coupler 52 for firmly anchoring the immediately adjacent tendon and thereby extending the post-tensioned rod upwardly through additional levels of the building unit. A plastic bearing strip or shim 54 is'positioned adjacent the interior edge of shoulder 42 and assures accurate leveling of the floor slab 16 prior to mounting of the overlying bearing wall panel 12. In this way each level of the building unit is individually adjusted for any variation which may be present in the precast concrete panels without compounding the variations over the total building unit.
As mentioned, each precast wall panel is provided with a peripheral shoulder recess 24 along its top horizontal surface and an elongated channel member 32 is seated therein in secure interengagement with the panel. As shown, the pliable plastic channel member 32 includes a central U-shaped trough portion 56 of rectangular cross section and a pair of integral supporting flanges 58, 60 projecting from both sides of the central trough along its entire length. In the particular embodiment chosen for illustrative purposes, the channel member 32 is cast into the panel so that the ribs 62 on the exterior of the central trough and the hooks 64 on the flanges are firmly embedded within the precast concrete panel. in this way the smooth, flat exterior surface 66 of the flange 58 is flush with the panel's top surface 20. The U-shaped trough 56 extends along the full length of the wall panel with its opening or mouth within the plane of the flush exterior flange, the opening exposing a plurality of longitudinally extending locking barbs 68 on the interior side walls of the trough.
A fluidtight sealing strip 70 is positioned between and cooperates with both the channel member 32 and r the confronting recess 22 of the adjacent panel to provide the beneficial connection of the present invention. The sealing strip 70 is a flexible deformable member made of a suitable elastomeric material exhibiting the requisite sealing properties. In this connection good success has been achieved with synthetic elastomeric plastics such as vinyl chloride polymers and copolymers, neoprene rubber compositionsor similar materials which provide flexibility and resiliency together with water-resistance, durability and toughness. The strip 70 is an elongated member comprised of a generally triangular central body portion 72 including a pair of transverse supporting arms 74 and 76 resting on opposite sides of the channel opening. A relatively thick anchor 78 extends integrally below the central body portion 72 and includes a plurality of ,outwardly projecting longitudinal locking ribs 82 extending along opposite sides of the anchor for cooperative interengagement with the internal barbs 68 of the trough so that upon insertion of the anchor 78 into the trough the locking ribs 82 cooperatively slide over and then lockably engage the barbs 68 to securely anchor the sealing strip within the channel member.
A water stop or barrier portion 86 of the strip is shown in the form of a hollow cylindrical member formed as part of the central body portion 72 and as an integral extension of supporting arm 74. The cylindrical water barrier 86 rests on the smooth flat surface 66 of supporting flange 58 and extends outwardly away from the central trough portion 56 toward the exterior surfaces 26. However, the barrier 86 is always well spaced from the exposed exterior surfaces 26 of the panel. The exact size of the cylindrical water barrier as well as its exact configuration may vary depending upon the particular precast wall panels being utilized. However, the barrier must be of sufficient size to assure contact by the overlying panel so that compressive deformation of the barrier 86 will provide a secure water seal at the seam between the wall panels. As best shown in FIG. 2, one edge of the tapered recess 22 and part of the confronting surface 18 of the overlying panel will contact the top'of the tubular fluid barrier and effect substantial deformation thereof. The full extent of deformation may vary depending upon a number of factors such as the manufacturing tolerances of the precast panels. It should be noted that it is an advantage of the present invention that the hollow cylindrical barrier 86 is readily adaptable to wide variations in the manufacturing tolerances of the wall panels and will accommodate wide variations both between and along individual panel elements.
The strip 70 further provides a secondary water barrier in the form of a ribbon-like spline extension 88 projecting upwardly from the integral central body portion 72 into the recess 22 in the overlying wall panel. The thin rectangular spline 88 is generally of sufficient height to contact the bottom of the recess 22 and be compressively deformed therein while at the same time providingback-up support for the cylindrical water barrier 86.
As will be appreciated, the sealing strip 70 can be easily mounted on the lower panel 14 by pushing the anchor 78 thereof into the central trough portion 56 of the channel so that the cooperative interengagement between the ribs 82 of the anchor and the barbs 68 of the trough effect secure locking engagement therebetween and retention of the seal strip in position for sealing upon lowering of the upper panel thereon. As shown in FIG. 2, the open joint is packed with a drypacked mortar composition consisting of a mixture of cement and sand grout which after being packed within the joint provides greater resistance to compressive forces than the plastic shims 54 used to level the floor slabs. The post-tensioning tendons 36 extending through the lower panel are tensioned prior to the addition of the dry-packing material and an additional length of tendon is connected thereto through the threaded connector 52 in the manner indicated hereinbefore. After providing an appropriate level for the overlying wall panel by means of plastic shims 54, it is guided into position by the upstanding tendons 36 to assure alignment with the adjacent underlying wall panel. As the overlying wall panel 12 comes into contact with the deformable seal strip 70, its weight deforms the hollow cylindrical water barrier 86 and deflects the generally rectangular spline extension 88 within its recess 22. A tension force is then applied to the post-tensioning tendons to effect further controllable and permanent compression and deformation of the water barrier and spline, and a tight contact between the cylindrical barrier member and upright spline at the position immediately above the central body portion thereof. As shown in FIG. 2, the triangular central body portion 72 of'the seal strip acts as a restraining member on the dry-packing material to prevent its outward movement through the joint and the compressive forces originally transferred by the shims alone are distributed over the dry pack and floor slab. Thus, the post-tensioning forces and the gravity forces of the structure compress and clamp the floor slab between the wall panels and create a semi-rigid joint and structural continuity between all members of the connection while assuring a watertight seal at all seams.
As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of the present invention.
l. A watertight seal connection for precast concrete structural panels comprising a pair of such panels disposed in aligned confronting relationship, said panels each having an exposed surface portion and an adjacent confronting surface portion provided with an elongated recess spaced from said exposed surface porthe length of the strip and a ribbon-like spline extendmg from the central ody portion toward and into the recess of the other confronting panel for deformably sealing the joint between the exposed surface portions of the panels as the panels are assembled in juxtaposed relationship and an anchoring member depending from the central body portion of the strip and extending into the trough, said anchoring member including locking ribs for lockable retention of the strip to the channel; a post-tensioning rod extending through the panels and securing them in overlying relationship; and drypacked mortar disposed between the overlying panels; the sealing strip confinably restraining flow of the mortar toward the exposed surface portions of the panel.
2. The seal connection of claim 1 wherein the underlying panel is provided with a shoulder spaced from the overlying panel, the connection including a third panel supported by the shoulder of said underlying panel and compressively secured between said shoulder and said overlying panel and leveling means between the underlying panel and the third panel.
3. The seal connection of claim 1 wherein the locking channel is provided with internal locking barbs within the trough cooperatively engaging the lockingrigs of the anchoring member for securing the sealing strip to the channel.
4. The seal connection of claim 1 wherein the locking channel is a pliable member secured to the panel, the trough is an elongated U-shaped portion having locking means therein and the locking ribs of the anchoring member cooperatively engaging the locking means of the trough portion for securing the sealing strip to the channel.