Abstract:
A lightweight block for interior partitions of buildings weighing less than one-half of any type of lightweight concrete block now manufactured, formed of a mixture of 10.66:1 ratio of expanded perlite aggregate and Portland cement, a water cement ratio of 6.66 gallons of water to 1 cubic foot of cement and an additive for making the mixture tractable, no other aggregate or binder being included.

Description:
This application is a continuation-in-part application of U.S. patent application Ser. No. 606,375, filed Aug. 20, 1975, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an extra lightweight non-load bearing building block, specifically for construction of interior building partitions or other non-load bearing interior walls. The block may be formed into standard or modular size building blocks similar in shape to commonly used concrete blocks, cellular or solid form. 
     2. The Prior Art 
     Heretofore, various types of concrete blocks have been manufactured and commonly used in construction for many years, such as cinder concrete block, stone concrete blocks and lightweight concrete blocks. The cinder concrete block, used in many instances for load-bearing, has lost favor in the construction industry because of its&#39; structural instability. The stone concrete block and lightweight concrete block are used for their load-bearing capabilities and in certain cases the lightweight concrete block is used for partitions. Because of weight however, existing lightweight concrete blocks are not commonly used for partitions and have been replaced by gypsum wall board or sheet rock partitions made of steel or wood studs and faced on both sides with gypsum wall board or sheet rock. 
     Existing lightweight concrete blocks are manufactured of expanded aggregates known as SOLITE, NYTRALITE, PUMICE, EXALITE and WAYLITE and are manufactured in standard and modular sizes, in cellular and solid form. SOLITE, NYTRALITE, EXALITE and WAYLITE are trade names for expanded shale. PUMICE is a variety of volcanic glass, full of minute cavities and very light in weight. These blocks are manufactured by using expanded shale or PUMICE, sand, cement and water in various mixes. The average weight of these commonly used lightweight blocks using a nominal 4 × 8 × 16 inches, three celled block as an example, range from 16.5 pounds to 18.2 pounds each, with an average weight, in place, in a wall including cement joints of 21 pounds per square foot. 
     Lightweight aggregates including perlite as an ingredient with clay are well known in the art, as evidenced in U.S. Pat. Nos. 2,699,409, and 2,728,733. Further building material employing expanded perlite, Portland cement and hydraulic binder with an additive is also well known, as evidenced in U.S. Pat. Nos. 2,858,227 and in 3,847,633 using additional aggregates and hydraulic binders. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of this invention is to provide an improved extra lightweight non-load bearing building block for use in preparation of interior partitions or walls of buildings. 
     Another object of the invention is to provide an improved extra lightweight non-load bearing block containing expanded perlite, as the only aggregate, and a plasticizer. 
     Still another object of the invention is to provide an improved extra lightweight non-load bearing block that can accept any surface finish now used in the construction industry. 
     A further object of the invention is to provide an improved extra lightweight non-load bearing block that is fire resistant, has excellent accoustical properties and can stand extreme abuse when used for non-load bearing interior partitions of walls. 
     A still further object of the invention is to provide an improved extra lightweight non-load bearing block that can be economically manufactured with present day block manufacturing equipment. 
     Other and further objects will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice. 
     DESCRIPTION OF PREFERRED EMBODIMENT 
     In accordance with the present invention the foregoing objects are generally accomplished by providing a building material, such as a block, extra light in weight, non-load bearing and for use for interior partitions or other non-load bearing walls on the interior of buildings. In the size of this block, which is similar to the standard or modular concrete block, now used in the building industry, a nominal 4 × 8 × 16 inches, three celled block as an example, weighs from 7 pounds 4 ounces to 7 pounds 12 ounces maximum, with an average weight, in place, in a wall including cement joints of 10.16 pounds per square foot. The air dry density (specific gravity) of the finished product is 41.2 pounds per cubic foot or 10.815 grams per cubic inch. Compression tests of this block have been made simulating a laid-up in the wall condition. In ultimate compression using a nominal 4 × 8 × 16 inches, three celled standard block, the block tested at 490 pounds per square inch of gross area, or 787.01 pounds per square inch of the net area. This non-load bearing block in place, for a partition or wall, can safely carry any height non-load bearing partition or wall used in building construction, as specified by all building codes nationally for the thickness of the block used. 
     This block is manufactured of expanded perlite conforming to ASTM C332 modified and manufactured classification as A-20, concrete grade, high-early strength Portland cement type IIIA, water and an additive to make the mixture tractable. No other aggregate or binder is used. Perlite is a petrographic term for a naturally occurring siliceous volcanic rock containing a small amount of combined water. When crude perlite ore particles are heated to plasticity, they expand 4 to 20 times their original volume, creating countless sealed air cells. 
     The expanded perlite aggregate shall have a maximum dry density of 8 pounds per cubic foot loose and 9 pounds per cubic foot compacted, and shall be sized as follows: 
     
         ______________________________________GRADATION             VOLUME______________________________________+  8 mesh              8 to 14%+  16 mesh            60 to 70%+   30 mesh           15 to 20%+  50 mesh            3 to 8%+ 100 mesh            0 to 5%______________________________________The additive necessary to make the mixture of expanded perlite,high-early strength Portland cement type IIIA, and water tractable, is amixture of 50% solids concentrate of triethanolamine salt of linearalkylate sulfonic acid, more properly termed triethanolamine salt ofP-dodecyl benzene sulfonic acid and 50% water. -The mix required shall be0.66:1 (10.66 cubic feet of expanded perlite to 1 cubic foot (1 bag) ofhigh-early strength Portland cement type IIIA), and a water cement ratioequal to 6.66 gallons of water to 1 cubic foot of cement. To this mixshall be added 0.67 to 1 pint of a mixture of 50% solids concentrate oftriethanolamine salt of P-dodecyl benzene sulfonic acid and 50% water.The mixture is known in the trade by the trademark &#34;MARK V&#34; manufacturedby Forrer Chemical Co. of Milwaukee, Wis., and its chemical formula isC.sub.12 H.sub.25 --(C.sub.6 H.sub.4)-- SO.sub.3 H.N(C.sub.2 H.sub.4OH).sub.3. -Equipment for the manufacturing process shall comprise aBesser or equivalent automatic mixer and a Besser V3R block moldingmachine or equivalent with adjustable vibration cycle timing, bins,chutes, conveyors and steam curing facilities. -Manufacturing processshall be as follows: The expanded perlite aggregate shall be predampenedand dumped into the mixer, feeding the required amount of cement andmixed for about 1 minute or until the cement is properly mixed with theexpanded perlite aggregate. Water shall then be added as the mixercontinues to operate until the total of 6.66 gallons have been used forthe mix, as described hereinbefore. The &#34;MARK V&#34; V additive shall beadded after the final water enters the mix. The above mentioned amount ofmaterial shall be mixed for 31/2 minutes plus or minus, until a tractablemixture develops and is then fed into a block machine set for a feed timecycle of about 21/2 seconds, and a final vibration time of about 2seconds. A standard squeeze is used to remove excess water and to developa neat even surfaced block. Total time including return shall be about 13econds. The block is next steam cured for a minimum of 6 hours and aircured for a total of seven days before use. -The finished extralightweight non-load bearing concrete block can accept any surface finishnow used in the construction industry on partitions: plaster, any type ofpaint, epoxy finishes, ceramic or plastic tile and vinyl wall coverings,as a few examples. -From the foregoing description it will be seen thatthe present invention provides an improved extra lightweight block forinterior walls of buildings that is fire-resistant, has excellentaccoustical properties and though extra lightweight can stand extremeabuse when used as intended for non-load bearing interior partitions orwalls. -As various changes may be made in the form, construction andarrangement of the parts herein, without departing from the spirit andscope of the invention and without sacrificing any of its advantages, itis to be understood that all matters are to be interpreted asillustrative and not in any limiting sense.