US 3342004 A
Description (OCR text may contain errors)
J. N. LUCAS Sept. 19, 1967 MASONRY WALL REINFORCEMENT WITH A-FRAME CONSTRUCTION 2 Sheets-Sheet 1 Filed Oct 7 1963 Jafi'qvlz ljaca a v BY f! WW Sept. 19, 1967 J. N. LUCAS 3,342,004
MASONRY WALL REINFORCEMENT WITH A-F'RAME CONSTRUCTION Filed Oct 7, 1963 2 S heetsSheet 2 United States Patent 3,342,004 MASONRY WALL REINFORCEMENT WITH A-FRAME CONSTRUCTION Joseph N. Lucas, Hammond, Ind., assignor to AA Wire Products Company, Chicago, 11]., a corporation of Illinois Filed Oct. 7, 1963, Ser. No. 314,328 2 Claims. (Cl. 52-695) This invention relates to improvements in tying devices for anchoring cavity masonry walls.
Cavity walls consist in two masonry walls or wythes of masonry separated by an air space. The two wythes are usually tied together by means of wall ties of various forms, a conventional form being 7 inch diameter wires bent into Z-shape and galvanized to prevent corrosion and set in the mortar beds and spanning the air space between the wythes of the cavity wall.
While such ties, and other conventional prior art ties may be generally satisfactory for many purposes, they offer no shear resistance, which materially strengthens the wall and is particularly desirable, in that where the cross ties can offer shear resistance, the resultant wall acts as the equivalent of a wide flange beam. The cross ties, therefore, in theory triple the strength of the wall.
A principal object of the invention is to improve upon the tying structures between the wythes of a hollow masonry wall so constructed and arranged as to provide the rigidity to cause the wythes to act as a solid wall section.
Another object of the invention is to provide an improved form of anchoring device for tying together the wythes of cavity wall structures made from different structural materials and transferring shear between the walls.
A still further object of the invention is to provide a simplified form of anchoring device for tying a hollow backing wall to a spaced solid facing wall of a masonry cavity wall structure, particularly arranged to place the central axis of the tying structure within the cavity between the walls, and to thereby place the tying structure in tension to add to the over-all strength of the wall and transfer shear between the walls.
Still another object of the invention is to improve upon the tying devices for tying a backing wall to a facing wall of a cavity masonry wall in which crossing tying rods between the walls are flush welded at their crossing points and flush welded to parallel spaced rods extending along one wall and cross in the space between the rods to form generally A-shaped locking structures, and are connected at their terminal end portions to a longitudinal rod in the mortar joint extending along the facing wall, in such a manner that the central axis of the tying structure will lie within the cavity between the backup and facing wall, placing the locking rods under tension, and acting as a shear transfer tie between the wythes of the wall, to thereby materially increase the strength of the wall.
These and other objects of the invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings wherein:
FIGURE 1 is a perspective view of a cavity or hollow masonry wall made up of a hollow block backing wall and a brick facing wall and illustrating one form in which the invention may be employed;
FIGURE 2 is a generally diagrammatic plan View of a locking structure constructed in accordance with the principles of the present invention;
FIGURE 3 is a fragmentary cross-sectional view taken substantially along line IIIIII of FIGURE 2 and illustrating a flush weld between the rods of the tying structure;
FIGURE 4 is a plan view of a modified form of tying structure; and
3,342,0M Patented Sept.'19, 1967 FIGURE 5 is a perspective view of a cavity wall, illustrating the form of tying structure shown in FIGURE 4 in which the cross rods cross in the cavity between the wythes of the wall.
In the embodiment of the invention illustrated in FIG- URE 1 of the drawings, I have shown a portion of a cavity masonry wall structure having a backing wall or wythe 10 composed of concrete blocks 11 secured together by mortar joints 12 and a parallel spaced facing wall or wythe 13 composed of bricks 15 secured together by mortar joints 16, with a cavity 14 between said walls.
It should here be understood that the present invention is applicable to various types of masonry wall structures and that the backing wall may be composed of concrete blocks, clay, tile bricks and the like, and the facing wall may be composed of face or common brick, glazed facing tile, glazed brick and the like.
Positioned along the tops of the concrete blocks 11 of the backing wall 10, along each mortar joint 12 of the backing wall are a pair of parallel spaced Wires or rods 17, 17 extending longitudinally of the wall. Positioned along the tops of the bricks 15 along a mortar joint 16, on the same level as the tops of the concrete blocks 11 is a third wire or rod 19 parallel to the rods 17, 17. The rods 17, 17 and 19 are shown as being knurled throughout their lengths.
Cross tying structures 21 suitably spaced along the wall are provided to tie the rods 17, 1'7 and 19 together, and to thereby tie the backing wall to the facing wall as well as strengthen the walls and prevent cracking thereof.
The cross tying structures 21 each comprise diagonal tying rods 23 crossing in the space between the rods 17, 17 and with said rods forming a generally A-shaped locking structure. The rods 23, 23 may be galvanized. The diagonal tying rods are flush welded together and are also flush welded to the rods 17, 17 and 19, as shown in FIG- URES 2 and 3. It will be noted from these figures that the flush welds increase the cross-sectional area of steel of the weld and not only compensate for the reduction in yield point, but strengthen theassembly so that the weld is the strongest part of the assembly. Also with such welds the lapped rods at the joints are compressed down so that the over-all thickness at the joints is not much greater than the thickness of the thickest single rod, as is evident from FIGURE 3.
The parallel rods 17, 17 and 19- may be of various suitable lengths depending upon the wall structure, an economical length for such rods being 10 feet. The cross rods 23, 23 may also be spaced at various desired spacings, one suitable spacing of said cross rods being 24 inches between the points of intersection of said rods.
It will be noted from FIGURE 3 that the angle between the crossing rods is 60, which is suitable for tying structures in general. In FIGURES 4 and 5 the angle between the crossing rods is shown as being which is a preferred angle where most efficient shear resistance is important. The spacing between the rods 17, 17 is preferably between five and six inches, a spacing of 5 /2 inches accommodating the structure for most concrete blocks. While the spacing may vary, this spacing may be considered to be a constant for concrete block backing walls.
The rods 19 may be spaced from the outer rod 17 in accordance with the thickness of the composite masonry wall including the backing wall 10 and the facing wall 13. Position A is shown in FIGURE 2 as being a suitable position for the rod 19 for a 12. inch wall, the distance between the inner rod 17 and the rod 19 being approximately 2% inches. B is a position of the rod 19 for a 14 inch wall. For such a wall a suitable spacing from the inner rod 17 is approximately 4 inches. C is a position of the rod 19 for a 16 inch wall. In this position, the wire 19 is spaced from the inner rod 17 a distance of substantially 6 inches. D is a position of the wire 19 for a 16 inch wall, the distance from the rod 17 being substantially 8 inches.
The rods 17, 17 and 19 while usually round, may be square or hexagonal or of any cross-section desired.
In the A frame locking structure just described, the crossing rods 23, 23 with the parallel rods 17, 17 and 19 produce a locking structure in which the central axis of the structure lies within the cavity 14. With such a structure, the crossing or tie rods 23, 23 will be under tension and since a weight load applied to the facing wall places the facing wall under compression and places the backup portion of the cavity wall under tension, the two wythes will then act as a solid wall, the crossing or locking rods will provide a shear transfer between the two wythes.
It should also be understood that the backup wall 10 is generally concrete masonry, which has a tendency to develop fringe cracking. This cracking tends to develop equally in both face shells of the block wall. The two parallel rods 17, 17 thus provide a double bond which in combination with the crossing rods 23, 2.3 materially reduces this cracking.
In the form of the invention illustrated in FIGURES 4 and 5, the cavity wall is similar to the cavity wall shown in FIGURE 1, so the same reference characters will be applied thereto as applied to the cavity wall shown in FIGURE 1. The pair of parallel spaced rods extending longitudinally of the backing wall are also the same, as is the rod extending along the mortar joints of the facing wall, the same part numbers will therefore be applied to said rods as is the form of the invention illustrated in FIGURES 1 through 3.
Cross tying structures 21a, 21a are provided to tie the rods 17, 17 and 19 together and to tie the backing wall to the facing wall and provide shear transfer between the walls. The cross tying structures 21: each comprise diagonal tying rods 23a, 23a crossing in the cavity 14 of the wall. The rods 23a, 23a like the rods 23 are flush welded together and are also flush Welded to the rods 17, 17 and 19. The angle between the rods 23a, 23a is 90 for most eflicient shear transfer. The crossing welded rods 23a, 23a provide a positive moisture barrier and eliminate the need for the conventional V-drip, and welding of the cross rolls at their crossing develops two opposing triangles transferring shear between the Wythe's of the wall.
While I have herein shown and described one form in which my invention may be embodied, it may readily be understood that various modifications and variations in the invention may be attained Without departing from the spirit and scope of the novel concepts thereof.
I claim as my invention:
1. A masonry Wall reinforcing device for locating in the adjacent mortar joints of a cavity masonry wall including a backup wall and a parallel spaced tying wall, comprising a pair of adjacent parallel relatively rigid metal rods adapted to be positioned in the mortar joint of the backup wall and to extend therealong, a single relatively rigid metal rod adapted to be positioned in the mortar joint of the facing wall and extend therealong in parallel relation with respect to said first mentioned rods, a plurality of relatively rigid crossing rod metal locking structures connecting said parallel spaced rods together, said parallel spaced rods and said crossing rod locking structures all lying in substantially the same common plane, means permanently joining said crossing rod locking structures at the points of crossing of said crossing rod locking structures and joining said crossing rod locking structures to said parallel spaced rods, compris ing flush welded connections between said rods attaining a rigid self-sustaining structure of lesser thickness than the thickness of the mortar joints, and the angles between said crossing rods being in the range of between and degrees.-
2. A masonry wall reinforcing device in accordance with claim 1 wherein the parallel spaced rods are knurled and the crossing rod structures are galvanized.
References Cited UNITED STATES PATENTS 327,360 9/1885 Vanes 52-695 475,116 5/1892 Ingraham 52--7l2 874,881 12/1907 Baker 52712 2,250,763 7/ 1941 Hild 52-426 X 2,929,238 3/1960 Kaye 52690 3,059,380 10/1962 Holsman 52-694 3,183,628 5/1965 Smith 52-694 FOREIGN PATENTS 575,392 5/1959 Canada. 397,055 2/ 1909 France.
19,949 9/1906 Great Britain.
FRANK L. ABBOTT, Primary Examiner.
RICHARD W. COOKE, JR., Examiner.
J. L. R'IDGILL, Assistant Examiner.