Compositions: coating or plastic – Coating or plastic compositions – Inorganic settable ingredient containing
Reexamination Certificate
2003-01-17
2003-10-28
Foelak, Morton (Department: 1711)
Compositions: coating or plastic
Coating or plastic compositions
Inorganic settable ingredient containing
C106S672000, C106S679000, C106S676000, C106S708000, C106S709000, C106S710000, C106S711000, C106S724000, C106S157900, C106S792000, C106S819000, C106S823000
Reexamination Certificate
active
06638355
ABSTRACT:
FIELD OF THE INVENTION
The present invention provides novel compositions, methods of their use and methods of their manufacture, such compositions generally useful as agents in the construction and building trades. More specifically, the compounds of the present invention can be used in construction and building applications that benefit from a relatively lightweight, extendable, moldable, pourable cementitious material that has high strength, good insulation properties and vermin resistance properties. At the present time, there is a need in the area of construction and building for such agents.
BACKGROUND OF THE INVENTION
In the field of preparation and use of lightweight cementitious materials, such as so-called lightweight aggregates the materials that have been available to the trades up until now have generally required the addition of various constituents to achieve a strong but lightweight concrete mass that has a high homogeneity of constituents and which is uniformly bonded throughout the mass. Of the methods known to the inventor, there have been several patents issued relating to the inclusion of expanded polystyrene beads of an average bead size of about 20 mm diameter (about 20,000 microns) that are expanded by various heating methods either before the beads are introduced into the concrete mixture, or expanded after they have been added to the concrete mixture. It is an object of this invention to provide for a pourable, lightweight cementitious mixture that does not rely on expanded polystyrene for weight saving properties and strength. It is another object of the present invention to provide for a pourable, lightweight cementitious mixture that can be used in the construction of molded roofing tiles. It is yet another object of the present invention to provide for a pourable, lightweight cementitious mixture that can be used in the construction of laminated building foundations, that is, the type of foundations in which a cement pour product is poured in between form walls that become part of the structural assembly upon curing of the cement. It is yet another object of the present invention to provide for a pourable, lightweight cementitious mixture that resists insect infestation and deterioration. Yet another object of the present invention is to provide for an extendable cementitious mixture that can be extruded through various extrusion dies and can be cured without further shape manipulation or formation. Still another object of the invention is to provide for a cementitious mixture that can be molded under high pressure and readily ejected from the mold with a minimum of green time to enable rapid re-cycling of the mold. Still one more object of the invention is provide a synthetic aggregate by curing and crushing a compressed product of an aqueous cementitious mixture.
SUMMARY OF THE INVENTION
The last of the foregoing objects of the present invention, i.e. the production of a synthetic or man-made aggregate, is achieved by curing and then crushing a compressed product made from an aqueous cementitious mixture comprising cement and at least one member selected from the group consisting of bottom ash and non-cementitious fly ash. Other additives such as polystyrene for reducing the weight of the compressed product but not its strength may also be added to the mixture. Prior to crushing it is also important to cure the compressed product so that it has a compressive strength of at least 600 psi. Once cured, the compressed product is crushed into fragments of a size which are capable of passing through mesh screen having sieve openings ranging from between about 19 mm and 75 microns. The crushed fragments now referred to herein as a synthetic or man-made aggregate is suitable for a multiplicity of uses such as for mixing with a cementing material to form concrete, mortar or plaster. Other uses include use as a filler and as a filtration media.
The invention comprises lightweight load bearing cementitious compositions that yield building materials having a density of 35 to 80 lb/ft
3
, comprising from 40 to 99% by volume of aqueous cementitious mixture and from 0 to 60% by volume of micronized polystyrene foam particles, the foam particles having a minimum density of 1.0 lb/ft
3
, and the water content of the aqueous cementitious product being present in a range of from 0.005 to 20% by volume. A more preferred range of water content is from 0.005% to 5% by volume, more preferably from 0.005% to 2% by volume. Preferred ranges of cementitious mixtures and micronized polystyrene foam particles are from 40 to 75% by volume cementitious mixtures and 25 to 60% by volume foam. More preferred ranges of cementitious mixtures and micronized polystyrene foam particles are from 50 to 60% by volume cementitious mixtures and 40 to 50% by volume foam.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The term “aqueous cementitious mixture” refers to any of a number of compositions comprising water, a cement material, and one or more fillers or adjuvants that form a slurry that hardens upon curing. Cement materials include hydraulic cements, lime, and the like. Adjuvants and fillers include bottom ash, fly ash, aggregate, air entrainment agents, crushed glass, recycled plastic, colorant agents and so forth. The compositions of the invention include a class of low water weight cement mixtures that have only from about 0.005 to 5% v/v of water added to the final mix. Such low water compositions have surprisingly been found to produce plastic cement mixtures that are readily processed through an extrusion die into a shape that needs no additional manipulation or molding after having been cut off subsequent to exiting the extrusion die. Also, the low water content compositions are well suited to being molded under high pressure, (e.g. in the range of five hundred to five thousand lb/in
2
). The advantage of such high pressure molding operations is that after removing the pressure, the molded article can be ejected from the mold very quickly, usually after three to twenty seconds or so, thereby allowing the mold to be available for another cycle of molding another article. Ordinarily, when a plastic composition is being shaped in a mold, there is some period of time that the composition must remain in the mold until it has sufficiently hardened to at least remove it from the mold, a period known in the trade as ‘green time’. The longer the green time of a given composition being used to mold articles, the fewer times the mold itself can be cycled during a work day. The extrusion and high pressure molding techniques and apparatus used in fabricating products out of the compositions of the invention are well known to those of ordinary skill in the art, and do not form a separate part of the invention as claimed herein, except to the limited extent they are a step in the process of making aggregate and articles out of the compositions of the invention. The compression stage of working with the compositions of the invention causes the material to be compressed down to approximately one third of its original volume. It has been found that articles molded out of these compositions lose the brittle quality of most molded cement or concrete compositions. For example, a roof tile pressure molded or extruded from these compositions doesn't shatter if dropped on the floor from a height of about three to four feet.
The term “cement” as defined herein refers to inorganic materials combined with water to form a hydrated bonded matrix. Hydraulic cement undergoes a hydration reaction in the presence of a sufficient quantity of water that produces the hardened product. The following are some typical hydration reactions:
Ca
3
Al
3
O
6
+6H
2
O, Ca
3
Al
2
(OH)
12
;
Ca
2
SiO
4
+x H
2
O—Ca
2
Si)
4
—xH
2
O;
Ca
3
SiO
5
+(x+1)H
2
O E Ca
2
SiO
4
—xH
2
O+Ca(OH)
2
The most preferred hydraulic cement for use in the invention is portland cement. Various embodiments of the invention call for the addition of lime (calcium oxide) which is itself also a hydraulic cement. Micronized polym
Foelak Morton
Smith, P.C. Brian D.
LandOfFree
Synthetic aggregate and method of producing the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Synthetic aggregate and method of producing the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Synthetic aggregate and method of producing the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3157542