Concrete curing blanket

Abstract

A concrete curing blanket includes an absorbent sheet having a wicking layer, super absorbent materials, and a tissue layer, which are laminated together to form the absorbent sheet. The absorbent sheet is sized for being spread over a curing concrete slab. A vapor barrier is bonded to the tissue layer of the absorbent sheet to inhibit evaporation from the concrete curing blanket, and includes a plurality of perforations.

Claims

1. A concrete curing blanket comprising: an absorbent sheet comprising a wicking layer and a tissue layer with super absorbent materials positioned between the wicking layer and the tissue layer; wherein the wicking layer and the tissue layer are laminated together with a heat activated bonding agent in the presence of heat and pressure to contain the super absorbent materials between the wicking layer and the tissue layer, such that the wicking layer draws water up into the super absorbent material of the absorbent sheet; wherein the wicking layer comprises lycocell, and wherein the super absorbent material comprises sodium polyacrylate; a vapor barrier bonded to the tissue layer of the absorbent sheet; and wherein the concrete curing blanket is at least 1 meter wide and 5 meters long.

2. A concrete curing blanket comprising: an absorbent sheet comprising a wicking layer and a tissue layer with super absorbent materials positioned between the wicking layer and the tissue layer; wherein the wicking layer and the tissue layer are laminated together with a heat activated bonding agent in the presence of heat and pressure to contain the super absorbent materials between the wicking layer and the tissue layer, such that the wicking layer draws water up into the super absorbent material of the absorbent sheet; wherein the wicking layer comprises lycocell, and wherein the super absorbent material comprises sodium polyacrylate; and a vapor barrier bonded to the tissue layer of the absorbent sheet, the vapor barrier having a plurality of perforations.

3. A concrete curing blanket comprising: an absorbent sheet consisting of a wicking layer of lycocell and a tissue layer with superabsorbent materials positioned between the wicking layer of lycocell and the tissue layer, the layer of lycocell being laminated to the tissue layer with a heat activated bonding agent in the presence of heat and pressure, such that the wicking layer of lycocell draws water up into the super absorbent material of the absorbent sheet; and a vapor barrier bonded to the tissue layer of the absorbent sheet.

4. The concrete curing blanket of claim 3, wherein the super absorbent materials comprise sodium polyacrylate.

5. The concrete curing blanket of claim 3, wherein the concrete curing blanket is at least 1 meter wide and 5 meters long.

6. The concrete curing blanket of claim 3, wherein the vapor barrier has a plurality of perforations.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings illustrate the present invention. In such drawings:

(2) FIG. 1 is a perspective view of a concrete curing blanket according to one embodiment of the present invention, illustrating the concrete curing blanket being positioned on a concrete slab while water is poured onto the concrete slab and into the concrete curing blanket;

(3) FIG. 2 is a sectional view of the concrete curing blanket taken along line 2-2 in FIG. 1, illustrating the four layers of construction of the concrete curing blanket in the embodiment of FIG. 1;

(4) FIG. 3 is a side elevational view of a first step of manufacture of the concrete curing blanket, wherein a wicking layer and a tissue layer are laminated together to contain the super absorbent polymers therebetween, and thereby form an absorbent sheet; and

(5) FIG. 4 is a perspective view of a second step of manufacture of the concrete curing blanket, wherein the absorbent sheet formed in FIG. 3 is bonded to a vapor barrier to form the concrete curing blanket of FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE INVENTION

(6) The above-described drawing figures illustrate the invention, a concrete curing blanket 10 that is used for providing hydration to a concrete slab C during the curing process, to provide concrete that has superior strength and durability.

(7) FIG. 1 is a perspective view of one embodiment of the concrete curing blanket 10, illustrating the concrete curing blanket 10 being positioned on the concrete slab C. As illustrated in FIG. 1, the concrete curing blanket 10 is manufactured in a roll that is sized for being unrolled over the concrete slab C to effectively cover the concrete slab C. The concrete curing blanket 10 is at least about 1 meter wide, and about 10 meters long. In a typical embodiment, the concrete curing blanket 10 is 1-3 meters wide (in this case about 2.5 meters wide), and about 30-60 (or more) meters long. In alternative embodiments, the measurements may vary according to the needs of the user, but they will be sufficiently large to be useful in covering concrete slabs, which may be of considerable size. As used in this application, the term “about” is hereby defined to include +/−10%.

(8) As illustrated in FIG. 1, before and while the concrete curing blanket 10 is being positioned on the concrete slab C, water is poured in large amounts onto the concrete slab C and into and over the concrete curing blanket 10, so that the concrete slab C remains thoroughly hydrated, and the concrete curing blanket 10 is thoroughly soaked. Once saturated, the concrete curing blanket 10 maintains an optimal amount of water in contact with the surface of the concrete slab C, which optimizes the strength and durability of the concrete when cured.

(9) While one form of concrete slab C is illustrated herein, the term “concrete slab” is hereby defined to include any form of structure that may require this form of hydration, including cement walls, pillars, and other structures known in the art. Indeed, due to the superior water carrying characteristics of the present invention, the concrete curing blanket 10 is particularly useful when used on angled or vertical cement structures, which might otherwise be difficult to keep hydrated.

(10) FIG. 2 is a sectional view of the concrete curing blanket 10 taken along line 2-2 in FIG. 1. FIG. 2 illustrates the four layers of construction of the concrete curing blanket 10 in the embodiment of FIG. 1. As shown in FIG. 2, the concrete curing blanket 10 comprises an absorbent sheet 22 comprising a wicking layer 24 and a tissue layer 26 with super absorbent materials 24 laminated therebetween. The concrete curing blanket 10 further comprises a vapor barrier 30 bonded to the tissue layer 26 of the absorbent sheet 22.

(11) The wicking layer 24 of FIG. 2 is a layer of material that is able to quickly wick up water from the pool of water formed on the concrete slab C (as shown in FIG. 1) as it is rolled onto the concrete slab C, so that the water is quickly and efficiently drawn into the concrete curing blanket 10. Water may also be poured directly onto the roll of the concrete curing blanket 10, to assure that the concrete curing blanket 10 is thoroughly hydrated. In the current embodiment, the wicking layer 24 is a nonwoven fabric, in this case a spunlaced nonwoven fabric comprising viscose. The wicking layer 24 may further comprise a polymer such as polyethylene, polypropylene, and/or polyester, which are useful in the bonding/lamination process, as discussed in greater detail below. In one embodiment, the wicking layer 24 comprises a combination of viscose and polyethylene.

(12) In one embodiment, the wicking layer 24 comprises a cellulose precipitated from an organic solution in which no substitution of the hydroxyl groups takes place and no chemical intermediates are formed (e.g. Lyocell). In alternative embodiments, alternative or equivalent wicking materials may also be used, using formulations that would be known to those skilled in the art, and such alternative or equivalent formulations should be considered within the scope of the present invention.

(13) The super absorbent materials 24 may include super absorbent polymers, super absorbent fibers, or other similar or equivalent materials. As used in the present application, the term “super absorbent polymers” (“SAP”) is defined to include polymers that can absorb and retain extremely large amounts of liquid relative to their own mass. Water absorbing SAP, classified as hydrogels, when cross linked, absorb aqueous solutions through hydrogen bonding with water molecules. A SAP's ability to absorb water is a factor of the ionic concentration of the aqueous solution. In deionized and distilled water, a SAP may absorb 500 times its weight (30-60 times its own volume), although this ability drops to only about 10% of this amount when salt is present.

(14) The total absorbency and swelling capacity are controlled by the type of and degree of cross-links used to make the gel. Low density cross-linking have a higher absorbency, which higher cross-link density exhibits lower absorbent capacity and swell, but greater gel strength and firmness.

(15) SAPs are commonly made from the polymerization of acrylic acid bended with sodium hydroxide in the presence of an initiator to form a poly-acrylic acid sodium salt, sometimes referred to as sodium polyacrylate. Other materials known in the art may also be used in this manner. In the present embodiment, the super absorbent materials 24 include a sodium polycarbonate polymer, and may further include additional additives, as discussed in greater detail below.

(16) As shown in FIG. 2, the concrete curing blanket 10 further includes the tissue layer 26, which in the present embodiment is a tissue fabric that is suitable forming a bond between the absorbent sheet 22 and the vapor barrier 30. The tissue layer 26 is a good surface for forming a good, strong, stable bond, and for preventing any bonding agents (glues, cements, bonding agents, etc.) from contaminating the super absorbent materials 24, and interfering with the ability of the super absorbent materials 24 from absorbing water. For purposes of this application, the term “tissue layer” is defined to include tissue fabric, and also any other materials known to those skilled in the art that is able to provide a good bonding attachment between the absorbent sheet and the vapor barrier.

(17) The vapor barrier 30 of FIG. 2 is a film comprising polyethylene or polypropylene or other material that is substantially vapor impervious, to prevent dehydration of the concrete curing blanket 10. The vapor barrier 30 may include perforations 32 so that water may be added from the top of the concrete curing blanket 10, so long as the perforations 32 are not large enough to enable excessive drying of the concrete curing blanket 10.

(18) FIG. 3 is a side elevational view of a first step of manufacture of the concrete curing blanket 10, wherein the wicking layer 24 and the tissue layer 26 are laminated together to contain the super absorbent polymers therebetween, and thereby form the absorbent sheet 22. In this embodiment, the super absorbent materials 24 further include a heat activated bonding agent, which facilitates the lamination of the three sheets together in the presence of heat and pressure. In this embodiment, the wicking layer 24, the super absorbent materials 24, and the tissue layer 26 are all laminated together under heat and pressure, such as via one or more rollers 40. Either the rollers 40 themselves may be heated, or a separate heater (not shown) may be included to apply suitable heat to the substrate moving through the rollers 40.

(19) While the present embodiment uses heat, other forms of bonding agents (e.g., contact cement, hot melt adhesive, etc.) may be used during rolling of the substrate, and may include rollers 40 that are not heated, or may omit the rollers entirely, so that the different layers are assembled in another manner known in the art.

(20) FIG. 4 is a perspective view of a second step of manufacture of the concrete curing blanket 10, wherein the absorbent sheet 22 formed in FIG. 3 is bonded to a vapor barrier 30 to form the concrete curing blanket 10 of FIGS. 1 and 2. In this embodiment, three of the absorbent sheets 22 are arranged side-by-side (or slightly overlapping) to be bonded to the vapor barrier 30, in this case also using rollers 40, although this is not necessarily required, as discussed above. As described above, heat, a heat activated bonding agent, contact cement, or other suitable adhesive or bonding element may be used to bond these two elements together to form the final concrete curing blanket 10.

(21) In use, the wicking layer 24 picks up water from the concrete slab C, as shown in FIG. 1, and from the wicking layer 24 the water is picked up (more slowly) by the super absorbent materials 24. While the wicking layer 24 can pick up the water quickly, it cannot store as much water, and while the super absorbent materials 24 take longer to absorb the water, they can in the end act as a reservoir for much larger amounts of water.

(22) Following installation, if the wicking layer 24 dries, water wicks from the super absorbent materials 24 back into the wicking layer 24, to maintain the proper hydration of the wicking layer 24 and the concrete slab C.

(23) As used in this application, the words “a,” “an,” and “one” are defined to include one or more of the referenced item unless specifically stated otherwise. Also, the terms “have,” “include,” “contain,” and similar terms are defined to mean “comprising” unless specifically stated otherwise. Furthermore, the terminology used in the specification provided above is hereby defined to include similar and/or equivalent terms, and/or alternative embodiments that would be considered obvious to one skilled in the art given the teachings of the present patent application.