US 2587724 A
Description (OCR text may contain errors)
March 4, 1952 A, H D RSON 2,587,724
PRECAST REINFORCED CONCRETE UNIT Original Filed Sept. 10, 1945 m,m,wm
Patented Mar. 4, 1952 PRECAST REINFORCED CONCRETE UNIT Albert Henderson, Pittsburgh, Pa., assignor, by mesne assignments, to Peoples First National Bank & Trust Company, Pittsburgh, Pa., a national banking association Original application September 10, 1945, Serial No. 615,265. Divided and this application December 11, 1946, Serial No. 715,514
This invention relates to a building construction utilizing precast reinforced concrete units and, in particular, to a novel unit adapted for use in the construction of buildings.
This is a division from my copending application Serial No. 615,265 filed September 10, 1945, now Patent No. 2,413,562, for precast concrete members.
The extensive use of precast concrete units in building construction has been prevented by the lack of satisfactory means for securing the members together by connections of sufiicient strength and rigidity. I have invented a novel form of precast building unit of reinforced concrete characterized by simple and effective provisions for easily and firmly uniting adjacent members. In a preferred embodiment, I embed pipe lengths in the ends of a precast reinforced concrete member adapted to receive tie means projecting from an adjacent member. The pipe lengths have anchor bars welded thereto which are also embedded in the concrete of the members. These bars lap the usual reinforcing bars so that a load applied to one member in a structure is transmitted through the connection to the pipe length and anchor bars in an adjacent member and, by virtue of the lapping of the anchor bars with the reinforcing bars, the load is eventually transferred to the latter by the bond between the concrete and the bars embedded therein.
A complete understanding of the invention may be obtained from the following detailed description and explanation referring to the accompanying drawings illustrating a preferred embodiment. In the drawings,
Figure 1 is a vertical section through the adjacent ends of a pair of alined girders, the column on which they rest and the footer on which the column stands;
Figure 2 is a partial section taken along the plane of line 11-11 of Figure 1.
Referring in detail to the drawings, a field-cast footer II] has anchor bolts II embedded therein and projecting upwardly thereabove. A precast column I2 including a shaft I3 and an integral base I4 rests on the footer I0. A layer of grout I5 is preferably spread on the footer before the column is placed thereon.
The column base I4 is larger than the shaft and has pipe lengths I6 embedded therein adapted to accommodate the anchor bolts II. Stirrups or cross ties I! extend around the pipe lengths and are welded thereto. The column is secured to the footer by nuts turned on the threaded upper ends of the bolts I I. These nuts are preferably provided with concrete protective covers I8.
The column I2 has longitudinal reinforcing bars I9 embedded therein. Stirrups or cross ties 2B extend around the bars I9 and are welded thereto. The upper ends of the bars project above the top of the column. The projecting ends of the bars constitute ties 2 I.
Girders 22 and 23 disposed in alinement endto-end, rest on the column I2. The girders are similar, each having lower and upper reinforcing bars 24 and 25 embedded therein with stirrups or cross ties 25 extending around the bars and welded thereto. As shown in Figure 2, there are three of the bars 24 and two of the bars 25 in each girder. Pipe lengths 27 are embedded in the girders adjacent their ends to form holes for receiving the ties 2i. The pipe len ths extend between adjacent bars 24. Short anchor bars 28 are welded to the pipe lengths and are embedded in the concrete of the girders between the bars 24 and 25. The anchor bars 28 lap the main reinforcing bars 24 and 25 so that any stress applied to the anchor bars is transmitted to the reinforcing bars through the bond thereof with the concrete.
The abutting ends of the girders 22 and 23 are beveled adjacent the top forming a notch or recess 29. The upper bars 25 have their ends fiush with the ends of the girders and are thus exposed in the notch 29 so they can be welded as indicated at 30, thus tying the girders firmly together.
The lower reinforcing bars 24 as well as the upper bars 25 extend beyond the pipe lengths, thus reinforcing the concrete at the extreme ends of the girders. This is possible because the reinforcing bars are located at one side of or between the pipe lengths and not in alinement therewith.
When the girders and column have been assembled, as shown in the drawings, the space between the ties 2| and the pipe lengths into which they extend is preferably filled with grout. When this has been done, a firm rigid connection is established between the reinforcing bars I9 of the column l2 and the reinforcing bars 24 and 25 of the girders 22 and 23. As previously explained, any load transmitted through the connection provided by the ties 2| and the pipe lengths 21 is transmitted from the anchor bars 23 to the reinforcing bars 24 and 25 by the bond between them and the concrete of the girder.
The invention thus provides a simple and effective connection for securing precast members firmly together in a building construction. No
special skill is required to make the connection and once made it remains permanently effective. The pipe lengths and anchor bars may easily be embedded in the concrete of the members by properly placing them in the mold in which the latter are made, along with the primary reinforcing bars 24 and 25.
Although I have illustrated and described a preferred embodiment of the invention, it will be recognized that changes in the construction 1 disclosed may be made Without departing from the spirit of the invention or the scope of the appended claims.
1. A precast reinforced concrete unit comprising an elongated mass of concrete having embedded therein and bonded thereto a longitudinally extending reinforcing bar and also having embedded therein and bonded thereto a metal member having a bore therein disposed transversely to and adjacent an end of the longitudinally extending reinforcing bar, the metal member intersecting a surface of the concrete mass and being adapted to receive a connecting mem ber, and an anchor bar also embedded in and bonded to the elongated mass of concrete, the anchor bar being relatively short with respect to the longitudinally extending reinforcing bar and being disposed in generally parallel side-by-side relation to the longitudinally extending reinforcing bar, the anchor bar being rigidly secured to the metal member and having a free end, whereby stress imparted to the unit through the metal member and the anchor bar rigidly secured thereto is transmitted to the longitudinall ex-- f? tending reinforcing bar through the concrete bonded to the anchor bar and the longitudinally extending reinforcing bar.
2. A precast reinforced concrete unit comprising an elongated mass of concrete having en1- bedded therein and bonded thereto a longitudinally extending reinforcing bar and also having embedded therein and bonded thereto a metal member having a bore therein disposed transversely to and adjacent an end of the longitudiimparted to the unit through the metal member and the anchor bar rigidly secured thereto is transmitted to the longitudinally extending reinforcing bar through the concrete bonded to the anchor bar and the longitudinally extending reinforcing bar.
REFERENCES QITED The following references are of record in the file of this patent and in the parent case:
UNITED STATES PATENTS Number Name Date v 1,094,841 Ellinger Apr. 28, 1914 1,259,698 Wilson Mar. 19, 1918 1,380,324 Piggins May 31, 1921 1,515,557 Dub-ee Nov. 11, 1924 1,562,706 Lake Nov. 24, 1925 1,734,364 Cole Nov. 5, 1929 2,334,355 Russell Nov. 16, 1943 2,372,200 Hayes Mar. 27, 1945 2,413,562 Henderson Dec. 31, 1946 FOREIGN PATENTS Number Country 7 Date 341,597 France 1904 49,182 Switzerland 1910 497,791 France 1919 510,055 France 1920 555,765 Great Britain Sept. 7, 1943 562,250 Great Britain 1944