CLIAMS:1. A fiber-reinforced concrete (FRC) product comprising at least one layer of fiber-cement and at least one layer of a polymeric material, wherein said polymeric material is laminated to said fiber-cement to form a fiber-reinforced concrete product.

2. The fiber-reinforced concrete product as claimed in claim 1, is in the form of a sheet or a block.

3. The fiber-reinforced concrete product as claimed in claim 1, wherein at least one polymeric material layer is coated on at least one surface of the fiber-cement layer.

4. The fiber-reinforced concrete product as claimed in claim 1, wherein the at least one polymeric material is laminated to the fiber-cement layer by using an adhesive such as epoxy resin.

5. The fiber-reinforced concrete product as claimed in claim 1, wherein the at least one layer polymeric material is in the form of a film, a woven fabric or a non-woven fabric sheet.

6. The fiber-reinforced concrete as claimed in claim 1, wherein the thickness of the at least one polymeric material layer is in the range of 150microns to 500 microns.

7. The fiber-reinforced concrete product as claimed in claim 1, wherein the flexural rigidity of the fiber-reinforced concrete product is in the range of 130 kg/cm2 to 190 kg/cm2.

8. A process for preparing fiber-reinforced concrete product, said process comprising the following steps:
a. applying at least one adhesive to at least one polymeric material;
b. pressing said polymeric material with said adhesive applied thereto to at least one surface of a fiber-cement layer and curing for a time period ranging from 10 days to 15 days to obtain a fiber-reinforced concrete product.

9. The process as claimed in claim 8, wherein the polymeric material is pressed to the fiber-cement layer with a pressure in the range of 2 kg/cm2 to 8 kg/cm2 for time period of 30 seconds to 120 seconds.

10. The process as claimed in claim 8, wherein said curing is carried out under wet conditions. ,TagSPECI:FIELD
The present disclosure relates to fiber-reinforced concrete (FRC) products and a process for preparing the FRC products.
DEFINITIONS
As used in the present disclosure, the following words and phrases are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicates otherwise.
Flexural rigidity: The term ‘flexural rigidity’ refers to the force couple required to bend a non-rigid structure to a unit curvature or it can be defined as the resistance offered by a structure while undergoing bending.
Woven fabric: The term ‘woven fabric’ refers to a textile formed by weaving and produced on a loom.
Non-woven fabric: The term ‘non-woven fabric’ refers to a fabric-like material made from long fibers, bonded together by chemical, mechanical, heat or solvent treatment.
Fiber-cement: The term ‘fiber-cement’ refers to concrete containing fibrous material that can take any desired shape.
BACKGROUND
Fiber-reinforced concrete (FRC) is concrete containing fibrous material which increases its structural integrity. FRC contains short fibers that are uniformly distributed and randomly oriented. The majority of the commercial FRC is prepared using asbestos fibers. Due to the toxic nature of asbestos, alternatives to asbestos fibers such as poly vinyl chloride (PVA), poly acrylonitrile (PAN), polypropylene (PP), polyethylene terephthalate (PET), glass fiber and the like are being tried. Commercially available FRC sheets have improved flexural strength, however, these are brittle in nature. Also, installation of the FRC sheets is laborious and requires heavy support structures. Further, due to poor aesthetic look, the FRC sheets are not well accepted in high end applications.
The present disclosure therefore, envisages a fiber-reinforced concrete (FRC) product that mitigates the drawbacks associated with the conventional FRCs.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the conventional FRC sheets or to at least provide a useful alternative.
An object of the present disclosure is to provide fiber-reinforced concrete (FRC) product having improved mechanical strength and that is resistant to catastrophic failures.
Another object of the present disclosure is to provide fiber-reinforced concrete (FRC) product which is lightweight, aesthetically superior and ductile.
Still another object of the present disclosure is to provide fiber-reinforced concrete (FRC) product that is environmentally safe.
Yet another object of the present disclosure is to provide a process for preparing fiber-reinforced concrete (FRC) product.
Other objects and advantages of the present disclosure will be more apparent from the following description which is not intended to limit the scope of the present disclosure.
SUMMARY
In one aspect of the present disclosure, there is provided a fiber-reinforced concrete (FRC) product. The FRC product comprises at least one layer of fiber-cement and at least one layer of a polymeric material, wherein the polymeric material is laminated to the fiber-cement to form a fiber-reinforced concrete product. The FRC product has improved mechanical strength, ductility and is resistant to catastrophic failures.
In another aspect of the present disclosure, there is provided a process for the preparing fiber-reinforced concrete products. The process comprises applying at least one adhesive to at least one polymeric material and pressing the polymeric material containing the adhesive to at least one surface of a fiber-cement layer and curing for a time period ranging from 10 days to 15 days to obtain the fiber-reinforced concrete product.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 illustrates a fiber-reinforced concrete (FRC) product prepared in accordance with the present disclosure using woven fabric;
Figure 2 illustrates a conventional FRC sheet;
Figure 3 illustrates a cracked FRC product of the present disclosure from the fabric side;
Figure 4 illustrates a cracked FRC product of the present disclosure from the non-fabric side;
Figure 5 illustrates the stress-strain curve for FRC product of the present disclosure and conventional FRC during flexural rigidity testing; and
Figure 6 illustrates a FRC product prepared in accordance with the present disclosure using a non-woven fabric
DETAILED DESCRIPTION
Cement structures are prone to crack formation due to shrinkage during the curing process. The shrinkage can be overcome by the use of fiber reinforcement in the cement matrix. The fiber-reinforced concrete (FRC) sheets thus prepared have improved flexural rigidity, however, they are brittle, resulting in breakages, which is undesirable. Also, the installation of the conventional FRC sheets is laborious, time consuming and require heavy support structures.
The inventors of the present disclosure therefore, envisage a fiber-reinforced concrete (FRC) product having improved mechanical strength and ductility and hence, are resistant to catastrophic failure and at the same time is light weight.
In accordance with an aspect of the present disclosure, there is provided a fiber-reinforced concrete (FRC) product. The FRC product in accordance with the present disclosure, comprises at least one layer of fiber-cement and at least one layer of a polymeric material.
In an embodiment of the present disclosure, the polymeric material is laminated on at least one surface of the fiber-cement layer using an adhesive. In another embodiment of the present disclosure, the polymeric material is laminated on both the surfaces of the fiber-cement layer.
In an embodiment of the present disclosure, the thickness of the at least one layer of the polymeric material in the FRC product is in the range of 150 microns to 500 microns.
The flexural rigidity of the laminated FRC is expressed in terms of “Modulus of rupture based on area” (MRA). The MRA of the FRC product prepared in accordance with the process of the present disclosure is in the range of 130 kg/cm2 to 190 kg/cm2.
In another aspect of the present disclosure, there is provided a process for preparing the fiber-reinforced concrete product. The process includes, but is not limited to, the steps presented herein below.
In the first step, at least one adhesive is applied to at least one polymeric material. The polymeric material in accordance with the present disclosure, includes, but is not limited to, a film, a woven fabric and a non-woven fabric. The flexural properties will be different when different types of fabric are used for lamination.
In an embodiment of the present disclosure, the adhesive can be epoxy resin.
In the next step, the polymeric material applied with an adhesive is pressed on to at least one surface of a fiber-cement layer and cured for a time period ranging from 10 days to 15 days to obtain the FRC product. The polymeric material can also be laminated on to both the surfaces of the fiber-cement layer.
The fiber-cement layer is prepared by known processes using asbestos and fiber, preferably R3S fiber. The amount of the asbestos in the fiber-cement layer is in the range of 5 wt% to 15 wt%. The asbestos is embedded in the FRC product prepared by the process of the present disclosure and hence, is less toxic as compared to the particulate asbestos.
In an embodiment of the present disclosure, the polymeric material is pressed to the fiber-cement layer using a pressure in the range of 2 kg/cm2 to 8 kg/cm2 using a hydraulic press, for a time period in the range of 30 seconds to 120 seconds. The curing is carried out under wet conditions.
After the completion of the curing of the FRC product, the sheets obtained are tested for flexural rigidity. The performance of the FRC product of the present disclosure is found to be better as compared to regular FRC sheets. Lamination of the two components i.e. the fiber-cement layer and the polymeric material enhances the functional and aesthetic properties of the FRC product.
The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. These laboratory scale experiments can be scaled up to industrial/commercial scale.

Experiment 1:
Woven fabric having an Ends per Inch (EPI) of 72 and Picks per Inch (PPI) of 80 having a thickness of 350 microns was used for lamination. FRC sheet was prepared by known process. Epoxy resin was applied on the fabric and then it was pressed on to a surface of the FRC sheet with a load pressure of 5 kg/cm2 for 60 seconds. The sheets so obtained were stacked on each other in open air for curing, with spraying of water at 24 hours interval for 14 days.
Experiment 2:
Non-woven fabric having Grams per Square Meter (GSM) 230, having a thickness of 180 microns was used for lamination. FRC sheet was prepared by known process. Epoxy resin was applied on the fabric and then it was pressed on the FRC sheet with a load pressure of 5 kg/cm2 for 60 seconds. The sheets so obtained were stacked on each other in open air for curing, with spraying of water at 24 hours interval for 14 days.
The toughness of the FRC sheet laminated with woven fabric (Figure-1) was found to be higher as compared to the regular FRC (Figure-2) without the lamination. It was observed that the flexural rigidity increased for the sheets prepared by coating at least one surface of the fiber-cement layer with a fabric. As depicted in Figure-6, the area under the stress-strain curve increases significantly for the FRC product of the present disclosure, as compared with the regular FRC sheet, indicating better ductility of the FRC product. In Figure-6, Curve-1 depicts the stress-strain curve of a regular FRC product and Curve-2 depicts the stress-strain curve of a FRC product prepared by the process of the present disclosure. The bonding of the fabric with the FRC and the nature of the fabric used contributes to the improved properties of the FRC products.
The FRC product of the present disclosure is prepared using polymeric material and is resistant to catastrophic failures. The FRC product of the present disclosure has increased ductility and flexural rigidity as compared to the conventional FRCs. Also, the FRC product can be given additional properties such as hydrophilicity, hydrophobicity, anti-insecticidal, fire resistance and the like. The reduced thickness of the FRC product make them light weight and easy to install. Further, the color of the FRC product can be customized as per the user requirement.
TECHNICAL ADVANCES
-The fiber-reinforced concrete (FRC) product of the present disclosure has improved flexural rigidity, ductility and is much more resistant to catastrophic failure as compared to the conventional FRCs.
-The FRC product of the present disclosure is lightweight, aesthetically superior and easy to install.
-The FRC product of the present disclosure can have properties such as hydrophilicity, hydrophobicity, insecticidal and fire resistance.
The exemplary embodiments herein quantify the benefits arising out of this disclosure and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.