TECHNICAL FIELD

This- invention relates to a precast concrete structural unit and to walls formed therefrom.

BACKGROUND ART

This invention relates generally to precast con¬ crete structural units for use in the construction of walls and the like in vertically stacked horizontal rows. More particularly, the invention relates to an improved precast

5 concrete structural unit of the general type shown in U. S. Patent No. 3,877,236.

It is the general object of the present invention to provide an improved precast concrete structural unit of the type mentioned wherein the structural integrity of the

10 individual unit is substantially improved with an attendant improvement in the structural integrity of a composite wall structure formed with a plurality of units stacked verti¬ cally in horizontal rows.

DISCLOSURE OF INVENTION

'In fulfillment of the foregoing-object, .-a-_~precast concrete structural unit is formed with a pair of laterally spaced longitudinally extending and vertically disposed side panels. Each side panel has a generally rectangular

configuration viewed laterally and each panel is of gen¬ erally rectangular cross-sectional configuration with only a slight inclination of its vertical walls for mold clear¬ ance. At the-top of each- panel.> -a- uniform planar sub-. stantially horizontal and longitudinally extending top surface is provided and a similar and parallel bottom surface- is ^: -also-provided on -each-panel. .-_

In accordance with the invention at least one vertically disposed generally rectangular and laterally _, • extending connecting arm is formed integrally with and joins with the panels at respective inner surfaces thereof whereby to secure the panels in relatively fixed position. Preferably, and as will be described, two connecting arms are provided in -longitudinally spaced relationship between the side panels.

Further, in accordance with the present inven- ^• tion, each connecting arm includes mating vertically projecting and vertically recessed lateral interlock means integral with the arm and arranged in top and bottom vertically opposite relationship. The interlock means include at least two complementary generally vertical bearing surfaces adapted for pressure engagement such that - - t-he""bottom lateral.-interlock, means on a connecting arm serves cooperatively with a top interlock means on a con- necting arm of an immediately sub-adjacent precast unit to laterally interlock two superposed units.

The lateral interlock means are gravity dependent with the depositon of one unit on top another necessary for the engagement of the interlock. However, the interlock means are physically positive laterally with the respec¬ tive generally vertical complementary bearing surfaces of the bottom and top interlock means ^' of superposed units in pressure engagement. Further, the planar top and bottom panel surfaces are interengaged in superposed units but provide lateral restraint only through gravity derived frictional forces. No enterengaging bearing surfaces provide lateral restraint between superposed panels.

As will be explained more fully hereinbelow thξ

connecting arms with bearing surfaces operative only between superposed connecting arms and with no lateral restraint other than gravity derived frictional forces acting between superposed panels results in greatlyimproved structural

5 integrity of the units. The strength of the units is found to be as much as 100% higher than that of the units in the above mentioned patent and, in some instances- even greater strength improvement is anticipated.

More particularly, and with regard to the improved

10 lateral interlock means, the connecting arms are provided - with mortise-tendon connections with a vertically recessed mortise and a complementary vertically projecting tendon arranged in vertically opposite relationship on the arm. Preferably the mortise is located at the bottom of each .

15 a m..and the.-.,tendon projects upwardly from the top of the arm and the aforementioned generally vertical bearing surfaces are defined at each side of each mortise end tendon. Further, the bearing surfaces are preferably inclined slightly from the vertical in a direction up-

20 wardly and inwardly toward the lateral center-line of the associated connecting arm. Still further, the mortise and tendon preferably each have a width less than 3/4 the width - - of ther_connecting-arm .whereby to -locate—the.-bearing sur¬ faces substantially laterally inwardly from the side panels

25 toward the center line of the connecting arms. In the presently preferred form each mortise and tendon is approx¬ imately 1/3 the total width of the structure unit and excellent strength characteristics are achieved.

In accordance with another aspect of the inven-

30 tion, connecting arms are spaced longitudinally from each other approximately twice the longitudinal spacing of each- arm from the adjacent end of the side panels. The struc¬ tural units may thus be adapted for vertical alignment of the connecting arms when the units are stacked verti-

^5 cally in horizontal staggered rows with the horizontal displacement between units in adjacent rows approximately one half the length of a unit. This results in columnar openings which are continuous vertically and which are adapted for the receipt of fill material. With

material deposited in the columnar openings.in a compos wall formed from a plurality of structural units, ^' integ vertical columns of fill material result within the wal - -and--enhanced overall structural integrity of the wall i 5 achieved.

As will be described more fully, the structur -units- are also...particularly _well.adapted to use in the struction of composite walls which may swerve as bearing walls as in the support of bridge structures and the li BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of an improved precast concrete structual unit constructed in accordan with the present invention.

Fig. 2 is a top view of the precast concrete 5 structural unit of Fig. 1.

Fig. 3 is an end view of the structural .unit Figs. 1 and 2.

Fig. ^' 4 is a vertical section taken generally indicated at 4-4 in Fig. 2. - ιo Fig. 5 is a top view of a portion of a compos wall structure formed with a plurality of precast concr structural units of Figs. 1 through 4.

Fig. 6 is a front view of the wall structure Fig. 5. 15 Fig. 7 is a front view of a portion of a wall structure similar to Fig. 6, but showing an alternative form of an end portion of the wall which inclines grad¬ ually downwardly from top to bottom.

Fig. 8 is a perspective view showing a small 20 bracket for interconnecting adjacent connecting arms of structural units at the corner of a composite wall structure having a right angular configuration.

Fig. 9 is a top view of a wall having a right angular configuration and employing a bracket of Fig. 8. 25 Fig. 10 is a front view of the Wall of Fig. 9.

Fig. 11 is a top view of a wall constructed fr the improved structural units and including a gradual angular change in direction.

Fig. 12 is a second embodiment of the Fig. 11 composite wall.

Fig. 13 is a front view of the Fig. 11 and/or 12 composite wall. Fig. 14 is a top view of an arcuate composite wall constructed with slightly modified precast concrete structural units in accordance with the invention.

Fig. 15 is a front view of- the Fig. 14 wall.

Fig. 16 is a side view of a composite wall structure including several vertical sections with struc¬ tural units of varying width and with conversion or transi¬ tion units at .the interface between units of different widths.

Fig. 17 is a fragmentary enlarged view showing - -.portions of.:-superposed precase structural units with a tubular filter element therebetween.

Fig. 18 is a fragmentary enlarged view .showing portions of superposed precast structural units with a tubular trim element therebetween. Fig. 19 is a fragmentary enlarged view showing portions of superposed precast structural units with a tubular composite filter and trim element therebetween.

Fig-. 20- is a fragmentary enlarged view showing portions of superposed precast structural units with a tubular trim element therebetween.

Fig. 21 is a fragmentary enlarged view showing portions of superposed precast structural units with a tubular trim element therebetween.

Fig. 22 is a fragmentary enlarged view showing portions of superposed precast structural units with a bearing element therebetween.

Fig. 23 is an end view of a composite wall structure formed with precast concrete structural units of a modified construction. Fig . 24 is an end view of a composite wall struc¬ ture employed as a bearing wall for a bridge structure.

Fig. 25 is a front view of the composite wall structure of Fig. 24. - ^uΪJRΕ "?^

BEST MODE FOR CARRYING OUT THE INVENTION

Referring particularly to Figures 1 through 4, it will be observed that a precast structural unit indicated -generally at 10.comprises-.a pair of laterally spaced longitudinally extending and vertically disposed side panels 12, 12. Each of the panels 12, 12 is of generally -:-r-e'ctanguia-r.--co.nf-igur-ation viewed.:laterally .and of a gen¬ erally -rectangular cross-section configuration. Slight ^• clearance angles for mold removal may be provided as

10 illustrated in Fig. 3. Further, sharp corners may be ounded or angled to facilitate casting and to prevent corner breakage.

At the top of each panel 12 a surface 14 is substantially planar and uniform and resides in a sub- - _y c stantially horizontal and longitudinally extending plane. Similar surfaces 16, 16 are provided at the bottom of each of the panels 12, 12.

In accordance with the present invention, the panels 12, 12 have at least one vertically disposed gen- 20 eral'ly rectangular and laterally extending connecting arm formed integrally therebetween and joining the panels at respective inner surfaces thereof. As shown, and as at •presently preferred the precast .structural units 10, 10 each have two similar laterally extending connecting arms 25 18, 18 and each arm is formed integrally at its ends with a panel 12. Further, fillets 20, 20 are preferably formed at the junction of the connecting arms 18, 18 and the panels 12, 12 for added strength.

Further in accordance with the invention, each of 30 the connecting arms 18, 18 includes mating vertically projecting and vertically recessed lateral interlock means integral with the arm and arranged in top and bottom ver¬ tically opposite relationship on the arm. The interlock ■- -means, includes at least two complementary generally ver- 35 tical bearing surfaces adapted for pressure engagement, and as will be seen herein below, the bottom lateral interlock means on a connecting arm serves cooperatively with a top interlock means on a sub-adjacent connecting arm to laterally interlock two superposed structural units ^ BURE/

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10, 10. The interlock means are gravity dependent, that is, the interlock means are engaged and disengaged by the assembly of the -units 10, 10 in superposed relationship

-.--. -■-■ but -when, the units.have been assembled, the interlock

5 means are physically positive to prevent relative lateral movement between superposed units, the aforementioned --compLementary-.-bearing-.-≤urfaces..being in pressure engage¬ ment with the units superposed. The aforementioned planar top and bottom panel surfaces 14 and 16, 16 are of course

10 also interengaged but they provide lateral restraint only through gravity derived frictional force ^' s as mentioned and there are no interengaging bearing surfaces associated with superposed panels. Thus, lateral interlock is achieved solely through lateral interlock means on connecting arms,

15 and the lateral interlock means have specific character¬ istics to be described and which provide for the substantial improvement in .strength and structural integrity of the precast units of the present invention.

In the presently preferred form, the lateral

20 interlock means on the connecting arms 18, 18 comprise a disengageable mortise-tendon connection with a vertically recessed mortise and a complementary vertically projecting tendon arranged in vertically opposite relationship on each connecting arm. As shown, each connecting arm 18 is ^"

25 provided with a vertically recessed mortise 22 at its lower surface and a vertically upwardly projecting tendon 24 at an upper portion of the arm. The aforementioned generally vertical bearing surfaces are provided by the mortises 22, 22 and the tendons 24, 24 and is best illustrated in Fig.

30 3, each tendon 24 defines opposite generally vertical bearing surfaces 26, 26 and each mortise 22 defines similar and. complementary -opposite surfaces 28, 28. Each of the surfaces 26, 26 and 28, 28 is inclined slightly from the vertical direction in a direction upwardly.and inwardly

35 toward ^" the lateral center line of its-associated connecting arm 18. The angle of inclination of each bearing surface

26, 28 should be less than 45° and within, the range 5° to

25°. Further, it is believed that an optimum angle of inclination falls in the range between 10° arid 15° a^^UREAt

illustrated in Figs. 1 through 4.

Still further, it is preferred that each mortise and tendon be approximately centered laterally on its con¬ necting arm 18 and the width of the mortises and tendons - should be ushc that the bearing surfaces defined thereby be spaced substantially laterally inwardly from the side panels 12, 12 toward the center line of the connecting arm. The width ^' of the mortises and tendons should be less than 3/4 the width of the connecting arm, and as shown and pre- 0 . sently preferred, each mortise and tendon 22, 24 has a width approximately 1/3 the total width of the structural unit 10. Excellent strength characteristics of the struc¬ tural units have been achieved with the mortise and tendon configurations and dimensions shown. 5 Further in accordance with the presently preferred form of the invention the connecting arms 18, 18 of the units 10, 10 are spaced apart longitudinally from each other so as to align vertically when the units 10, 10 are stacked vertically with adjacent horizontal rows of units staggered vertically. That is, the unit 10 shown has connecting arms 18, 18 spaced longitudinally approximately twice the longi¬ tudinal spacing of each arm from the adjacent end of the side panels 12, 12. The unit 10 is thus adapted for verti¬ cal alignment of connecting arms when units 10, 10 are stacked vertically in horizontally staggered rows with horizontal displacement between units in adjacent rows approximately one half the length of a unit. Thus, units 10, 10 in Figs. 5 and 6 are stacked vertically in horizontal rows staggered one half a unit length and the connecting arms 18, 18 align vertically as shown by broken line in Fig. 6.

Vertical alignment of the connecting arms 18, 18 as described is important in the provision of vertically extending columnar openings 30, 30 which are adapted to receive fill material in a composite- wall structure as in Figs. 5 and 6. With vertically continuous or columnar openings such as 30, 30 the fill material has integrated characteristics to the overall strength of the composite wall. Obviously, the fill material may be compacted

desired and various types of. fill material may be employed as dictated by the requirements of a given installation. As will be apparent from Figs. 5 and 6, the end --.of ^: -a-composite wall formed by.-.ver.tieal,l-y.r.^.tacking,...units 10, 10 may employ half units such as 10a in alternate rows. Further, in order to close the ends of the units 10 and slatos .-3-2,~-32.-ma-y_iιe-provided. Still further H shaped members may be employed intermit¬ tently as at 33, 33.for longitudinally locking .superposed units. Alternatively, when it is desired to provide an inclined end surface of a composite wall as. in Fig. 7, special triangular units 10b, 10b may be provided.and a top member in the form of a slab or slabs 34, 34 may be provided to close openings at the end of the wall. Similiarly, a cap 36 may be provided along the top of the wall. The caps or slabs 34 and 36 may of course .be con¬ structed sectionally employing precast slab sections.

In Figs. 9 and 10 the manner in which a composite wall structure may be formed with units 10, 10 is illus- trated in a right angular configuration, that is, the units 10, 10 are adapted for a right angle or 90° turn by arranging an end unit 10c at right angles in a second row or course above a first unit 10. A insert 32 as in Figs. 5 and 6 is employed and the cross or connecting arms 18, 18 of the units 10, 10c are preferably connected together by a bracket 34, Fig. 8. The bracket 34 has right angularly directed U-shaped sections respectively for fitting the tendon 24 of a lower unit 10 and the mortise 22 of an upper unit 10c. Obviously, alternate rows or courses of units 10, 10c may be arranged at right angles and brackets such as 34 may be employed in each instance to secure verticall -adjacent units 10, - 10c.

In Figs. 11, 12 and 13, special units are shown for constructing a composite wall with angularly related sections at angles' less'than 90°. In the first row or course of units 10, 10 in Fig. 13, precast units 10b, lOd have rear panels 12d, 12d, Fig. 11, which are somewhat shortened to provide for the angular relationship of the wall sections. In the second row or course of

Fig. 13, the precast unit lOe has front and rear panels

12e, 12e, Fig. 12, each having first and second angularl related portions complementary to the angles formed by t two panels 12, 12d in Fig. 11. The third row or course units 10, lOd in Fig. 13 reverts to the arrangement of t first row and the fourth row may correspond to the secon row 10, lOe of precast units.

In Figs. 14 and 15, units lOf, lOf take a grad arcuate configuration ^" viewed from above. Obviously, the ^' arc may vary as desired and the units may be employed in constructing arcuate sections of composite wails or, alternatively, the units may be continued in the arcuat arrangement to form full circular silo type structures. In Fig. 16, variations in the construction of the precast units are illustrated and it will be observe that panel size may be maintained similar with cross or connecting arms varying in length to provide units of various width. . It will also be obvious that side panel size may be varied as desired. In the composite wall ^' structure of Fig. 16 the widest precast units lOg are arranged in three lowermost rows with the third row comprising units lOg which may be referred to as conver¬ sion or transition units. The lateral positioning of the tendons at the tops of the cross arms 18 in this row are such as to correspond to the like positioning of the mortises in the units lOh thereabove. Similarly with regard to the uppermost units lOh wherein the tendons are positioned laterally to correspond to the mortises o the rows of units lOi. The uppermost unit lOi illustrat is also a conversion or transition unit as is the upper¬ most unit 10j. Obviously, many variations of units can employed in combination in accordance with requirements a given installation as to wall height, forces to be exerted on the left hand side of the wall assuming that the wall is used as a retaining wall, and other variable The flush right hand front face of the wall roay also be stepped back as by omitting transition units and plantin may be provided in the stepped back portions.

Figs. 17 through 22 illustrate joint treatment and in each instance, the joints illustrated may be regarde as either horizontal or vertical joints between precast -units- 10, O. Fig. 17 illustrates ^: a-.cTόsed ^" cell rieoprene

5 sponge material in tubular form which may be disposed be¬ tween vertically adjacent units and compressed as illus¬ trated f-roih its full -line.-formr34- to-broken Tine form 36. The filter material serves to prevent "fines" or fine fill material from the interior of the units forming a wall

10 _. passing outwardly with water or other liquids at. the joint areas and causing stains on the front surfaces of the -. units.

In Fig. 18 a trim member 38 is illustrated be¬ tween vertically adjacent units and is adapted particularly 15 for horizontal joints any slight roughness or uneveness at the joint area will be concealed by the trim member ^' 38 with the units in place. The trim member 38 has a generally T configuration with a V-shaped body portion which is captured between the units 10, 10 and compressed to secure

20 the trim member in position when the units are moved into engagement with each other.

Fig. 19 illustrates a composite filter and trim member."-The -member- 40 trim- portions- 42 and 4.4 both gen¬ erally T-shaped and a tubular filter member 46. With the'

25 member captured between units 10, 10 the filtering func¬ tion as well as the trim function is achieved automatically.

In Fig. 20 a trim member similar to the trim member 38 is illustrated at 48 and takes a generally T- shape with a U-shaped body portion. The U-shaped body

30 portion is captured between the units 10, 10 and when . compressed fixes the trim member in position with the arms of the—member concealing: he joint-between units.

In Fig. 21* a simple T-shaped member 52 is captured between units 10, 10 to provide a trimming function-only.

35 ^~ In Fig. 22 a bearing member 54 is- provided at the joint between units 10, 10. The bearing member 54 is preferably employed in a composite wall structure wherein the wall serves as a bearing wall and where it is desirable or necessary to provide for uniformity of bearing loads—-—» _^ ^BU E

( O PI ^"

between the units 10, 10. With the bearing member disp in the joint, bearing loads are distributed substantial uniformly from one unit 10 to another despite any non- uniformity or irregularity on the surfaces of the units

5 The bearing member presently preferred comprises an asp impregnated felt member disposed in joint areas and the after held when the units are placed atop one another.

In Fig'. 23, a further embodiment of the impro precast concrete structural unit of the present inventi

10 _. is illustrated at 10s. Units 10s, 10s illustrated from single two row or two course composite wall viewed from the end and each of the units comprises spaced apart panels 12s, 12s and a pair of _. connecting arms 18s, 18s, one shown. Each connecting arm 18s has a mortise 22s a

15 lower portion and a tendon 24s at an upper portion ther All portions of the units are substantially the same as those described for Figs. 1 through 4 except for the provision of a shingled exterior effect provided by sma depending flanges 56, 56. The flanges 56, 56 are forme 0 at lower edge portions of the side panels 12s, 12s and illustrated at the junction at the lower and upper units 10s, 10s, the lower edges of the flanges 56, 56 conceal the joint areas 58, 58 between the units 10s, 10s. It should be noted that the lateral dimensions and toleranc 5 between inner edges of the depending flanges 56, 56 are related to the lateral dimensions and tolerances of the mortises 22s, 22s and the tendons 24s that the bearing surfaces 26s, 28s always engage prior to engagement of a flange 56 with a top edge of a sub-adjacent panel. Thus 0 lateral displacement of units 10s, 10s relative to each other as might damage or break the flanges 56, 56 is avoided.

Further, the units 10s, 10s are constructed wi connecting arms 18s, 18s projecting downwardly beneath t 5 normal surfaces of the side panels 12s ₍ 12s. Thus, the flanges 56, 56 are protected as illustrated with the flanges 56, 56 of the lowermost unit 10s. When the unit

10s, 10s are transported damage to the flanges is thus avoided. ^'

n or er a e un s may proper y nes stacked relationship, the upper portions of the connecting arms 18s, 18s adjacent to tendons 24s, 24s are recessed vertically to receive the downwardly projecting lower portions of the arms when the units are in stacked rela¬ tionship. Thus, the recessed portions 60, 60 of the arm 18 receives the downwardly projecting portions 62, 62 of the arm 18s thereabove with the units 10s, 10s stacked as illustrated. . — 0 Various types of caps, slabs- etc. may be provided at the tops of composite wall structures formed with the precast units of the present invention and, in Fig- 23 a precast unit is provided which may be employed- in planting shrubbery, etc. for beautification of a top surface of a 5 wall. Thus, a unit 64 may be precast with a mortise 66 to ^~ -receive the'"tendon"-24s-Of the^ ^' uppermost ^{^} connecting -arm 18s and of similar arms therebehind. Side walls 68, 68 define a trough or planting bed 70 which may be filled with - appropriate material for the planting of shrubs, flowers, ⁰ etc.

Figs. 24 and 25 illustrate the use of improved precast structural units of the present invention in a bearing wall which serves as a bridge abutment. Three (3) rows or courses of units 10m, 10m ^* "are somewhat wider than 5 t o (2) rows or courses of units lOp, lOp thereabove. The uppermost unit 10m shown may be a conversion or transition unit as described in Fig. 16. The units 10m and lOp are stacked vertically and in staggered horizontal rows as illustrated in Fig. 25 to support a bridge structure indi- ° cated generally at 72 in Figs. 24 and 25. Base or founda¬ tion slabs or slab means 74 may comprise sectionalized precast slabs, and a top or bearing slab 76 may be of similar construction. Preferably, upstanding precast concrete blocks 78 are also provided for support of bridge 5 structure 7.2- and- it- will be apparent- hat.-the .slab -76 may be notched or mortised as required to receive tendons along the arms of the uppermost row of the units lOp, lOp. Preferably, the three rows of courses of struc¬ tural units 10m, 10m are secured in position as shown by

employing tie rods 80, 80 which extend vertically throu the foundation means or slabs 74, 74 upwardly through t units 10m, 10m and engage a horizontally extending beam beam means 82. The beam 82 may comprise precast sectio atop rear portions of the units 10m, 10m and the tie ro may be conventional construction entered in precast ope ings in the slab 74, 74 and the beam 82. The composite wall structure is preferably inclined slightly from the vertical when employed as a bearing wall as in the brid abutment shown with retained material on the right hand side of the wall. The angle of inclination may vary bu is preferably a few degrees. Further, the joints betwe units 10m, 10m preferably include the compressable bear material mentioned above for distribution of loading effect substantially uniformly throughout the joint are

As mentioned above, the improved precast stru ural units of the present invention provide for substan tially increased strength and for superior wall ^" constru • tion. When the units are employed in a retaining wall, common use therefor, the material is retained by the wa at a rear side thereof applies a. force to the units in wall which is felt along force lines angled downwardly forwardly. In tests of the improved units of the prese invention with forces applied angularly to simulate the forces felt in a retaining wall environment, the struc¬ tural units of the present invention exhibited strength characteristics 100% superior to those of the structural units in the aforementioned patent and in certain instan the strength improvement has substantially exceeded 100% This was achieved with units having substantially iess concrete and less than half the steel reinforcement of the patented units. The improved strength characteristi are believed to derive from the particular type and loca tion of the lateral interlock means of the present inven tion. That is, the reactive forces in the- structural units occur through the connecting arms with the concret primarily in compression and there are no interengaging lips on bearing surfaces along the edges of the panels a in the patented structural units mention

connecting arms and si e pane s o not ten to separate - adjacent their lines of juncture as is found in testing the units disclosed in the patent.

........... Walls~....constructed. with the units exhibit similar improvement in strength characteristics and may be raised to heights substantially twice as high as with the patented units.. -

INDUSTRIAL APPLICABILITY

The foregoing invention relates to "manufacture and use" of a precast concrete structural unit and to walls formed therefrom.