The present invention relates to dry-stack concrete masonry system for building stuctural load bearing and non-loadbearing walls and, more particularly, two distinct concrete masonry units with a web offset lug design that provides for both stack bonding and running bond construction with unobstructed vertical cell alignment to facilitate both solid and partial concrete grouting (for structural strength) with and without steel reinforcement.
The key advantage of mortarless masonry systems is that the labor component to install can be dramatically reduced. Some studies have showed that mortarless masonry systems are up to 10 times faster to install than conventional mortared masonry systems. Because these systems do not use bonding mortar to provide structural support it is imperative that other means of developing wall strength be used. A viable technique to develop wall strength is to pour wet concrete grout) into the openings of the block (cores) to form vertical posts that are almost always reinforced with steel (rebar). The problem with many mortarless block systems (and especially those that do not require a core-puller to produce) is that when dry-stacked, the cells (or core holes) of the block do not line up very well . . . or the cells are of different sizes which provides little or no damming capacity when partially grouting a completed wall structure. Many dry-stack mortarless block systems require lugs that project above the top surface of the block by a 3/8 inch or more . . . these lugs tend to limit where block can be stacked in relation to one another. In order to provide structural integrity, dry-stacked concrete block walls must be filled (solid or partially) with grout to meet various building codes. The wet concrete grout is poured into the open cells of the concrete block . . . sometimes all the cells are filled (grouted solid) or sometimes the grout is poured into distinct vertical columns down only certain cells/cores of the block (partially grouted) . . . generally on 4′ centers and at wall corners and jambs of windows and doors.
A good general overview of the use of current dry stack methods in masonry wall construction can be found in NCMA National Concrete Masonry Association) technical publication TEK 14-22 “Design and Construction of Dry-Stack Masonry Walls”.
The present dry stack/mortarless wall systems used in building construction for load bearing and non-loadbearing that incorporate raised lugs for alignment and interlocking do not provide adequate or uniform core orientation. The prior art for raised lug systems has been well documented by Ivany in U.S. Pat. No. 3,968,615 . . . by Cook in U.S. Pat. No. 4,182,089 . . . by Haener in U.S. Pat. No. 4,640,071. The shortcoming of all of these inventions is the inability of the block when stacked in a running bond (one block resting on top of two halves of lower adjacent blocks) configuration to provide for a uniform and well aligned core (from bottom of wall to top of wall) for grouting . . . in addition, prior art does not allow for the stacking of block in a stack bonded configuration (one block resting completely on top of a lower adjacent block) because of the interference problem with the raised lugs.
It is therefore an object of the invention to provide an improved dry-stack concrete masonry unit (CMU) for constructing masonry load bearing and non-loadbearing wall assemblies.
It is another object of the invention to allow for improved core alignment from bottom to top of wall construction.
It is another object of the invention to make partial grouting easier and stronger.
It is another object of the invention to make structural steel reinforcement of wall assembly easier and faster.
It is another object of the invention to allow the installer to construct in both a running bond and stack bonded orientations.
In accordance with the present invention, there is provided a means to dry stack concrete block providing improved structural strength by grouting—especially partially grouting techniques and providing no web interference even in stack bonded configurations. Instead of having concrete block cells of different sizes—one on top of the other from one course to the next—during the dry-stacking process, the invention provides for the cells of the blocks to line up perfectly to provide a well defined column for concrete grout . . . making it easier, faster . . . and technically superior to the current mortarless systems using raised lugs and other known methods) for face shell alignment. The improved cell alignment is provided in both running bond and stack bonded dry-stack construction techniques.
A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which:
For purposes of clarity and brevity, like elements and components will bear the same designations and numbering throughout the FIGURES.
Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.
The present application is a continuation-in-part application of U.S. provisional patent application Ser. No. 60/529,457, filed Dec. 12, 2003, by Alan Corbett Ferguson, included by reference herein and for which benefit of the priority date is hereby claimed.
Number | Date | Country | |
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60529457 | Dec 2003 | US |