Title of Invention


Abstract This invention protects reinforced concrete against thermal, rust cracking. It has a short cylindrical transparent plastic capsule, closed at one end and having a sleeve on the open side. The sleeve has a hole for the steel rod and radiating cuts that will adjust for various rod diameters! Inside the capsule is cylindrical foam with antirust chemicals and enclosed in a thin plastic film cover. The capsule has marking for correct application on steel rod end. The capsule has an external downward projection to support and fix in concrete. After the steel rod mesh is made, the capsules are fitted to the ends of rod to the mark, concrete mortar is poured, allowed to set and cure. The concrete now, even if exposed to sun gets heated, steel rods expand into the foam and when cool the rods contract, without any expansile stress on the concrete slab, preventing cracks and adding years of life! For rods with bent ends the capsule is broader for the bend, with foam and sleeve modified.
Full Text A Reinforced Concrete Thermal Expansion Protector
Technical Field
This invention in general relates to reinforced concrete protection. Precisely this invention relates to a novel kind of capsule that is applied to steel rods to prevent thermal expansion cracks in our hot tropical country, preventing rusting, prolonging life of concrete for more years.
State of Art
Existing Reinforced concrete structures as roof, bridges do not last long as expected in coastal and tropical India. A large number of additives were tried as concrete protector, also zinc coating, but surveys have shown march of corrosion! The large cost in repairs, still do not increase durability after repairs. Hence prevention of crack formation will only stop corrosion! There is a large daily variation in heat from cool mid nightl5*C to hot midday of 60*C, that heats the slab. The metallic steel rods have a higher coefficient of linear and volume expansion than the nonmetallic sand or gravel in the mortar. Tons of steel mesh of long lengths create a large expansile force on the concrete that finally cracks at the borders or the bottom of the concrete. Cracks allow moisture to enter and rust the steel, corroding, expanding the cracks, losing tension and collapse finally, in few years!
Existing methods of chemical additives, zinc coating are half measures only! There are no physical devices that eliminate cracking forces!
Ideal protection should be: 1.eliminate expanding steel forces.2 improvement of cement mortar steel bonding with no air trapping! 3.avoid rusting even if concrete is cracked. The following description gives critical examination of the inhalers known in the art. It also discusses the shortcomings of the conventional methods and on offers the solution to overcome the impediments in the construction and the process of using the same.
Constraints in the existing concrete protection are as follows:
1. There is no elimination of thermal steel expansion, a physical event.
2. The chemical additives are not thermal protectors.
3. The concrete laying and setting is not perfect.
4. The steel rods are not perfectly supported in concrete pouring and setting stage.
5. The thermal cracks allow moisture entry, rusting starts, cracks increases, steel losses strength and collapses.
Accordingly the object of the invention is to identify the problem associated with the conventional protection. An extensive search has been carried out using the Internet and related patent specifications were studied for thermal expansion preventors. Since the present invention is radically different, the inventor is unable to site any patent specification out of the available databases.
The invention is directed to a novel type of protector, which is most effective for thermal expansion prevention. Further the invention is addressed to the process of using the new device, which is unique in design and construction, working, and use. Further objects of the invention will be clear from the ensuing description.
Summary of the invention:
The device comprises of a transparent short capsule, fixed to the ends of steel rods after laying .The capsule contains compressible foam that also has anti rusting compounds that delay bacterial growth or iron rusting! The foam allows for expansion and contraction of steel rods, without transferring the expansile forces to the concrete! The capsule has markings on its outside to correctly apply by illiterate worker. The capsule has a lower projection to support the steel mesh in actual setting! The capsule has a close fitting sleeve for the rods that prevents water entering the foam in setting! Once set, any amount of steel expansile force is taken by the foam that is compressed in hot or expands in cool without air trapping! Anti rust chemicals further protect the rods!
Statement of Drawings:
These and other objects and features of the invention will become more apparent upon perusal of following description taken in conjunction with accompanying drawings wherein:
Figure 1 shows in elevation the constructional details of protector. Figure 2 shows the various components.
Figure 3 shows the exploded view of the action, (a) in hot day with compressed foam, (b) cool with expanded foam in night.
Figure 4.shows another embodiments of the invention with for U bends. Figure 5.shows another embodiments of the invention with for bends
The following specification describes salient features of invention, the method of
construction, the method of use and the advantages of the novel invention.
The novel device has a short cylindrical capsule with a covered foam in its inside, to absorb the steel thermal expansion and prevent cracks.
The novel device according to the invention is fitted to ends of steel rods mesh and concrete is poured and allowed to cure and set for better effect.
The novel device according to invention is better because the foam now absorbs the thermal expansion of steel rods, with no cracking force transmitted to concrete. Special feature of the invention is that it is easy to apply by illiterates too. The novel device has anti rust chemical embedded with the foam that also adds to protection. The conventional additives and improved cement do not totally prevent the cracking thermal forces. The concrete protection methods have not been improved for decades. The object of the invention is to overcome the inherent defects. To this end the new invention is addressed!
The device comprises of a short transparent plastic capsule 1, with a bold marking 2, for correct application! Short cylindrical foam 3, enclosed in a thin plastic cover 4, fits the inside of the capsule. The foam has anti rust chemicals that prevent bacterial multiplication and steel rusting within the sealed plastic foam cover. The foam takes up the expansible stress with a new anti rust function. The capsule has a lower supporting projection 5 to correctly fix and hold the steel rods in setting! The legs may be simple single projection or modified! A sleeve 6, fits the mouth of the capsule with a central hole 7, for the steel rod 8 The sleeve has clefts 9 to adjust for easy fixing on various sizes of rods.
To use, after the needed concrete steel rod mesh is laid, the capsule with the foam inside and the sleeve is fixed to the ends of all rods to the correct mark 2. Concrete mortar is poured and allowed to cure and set! Weathering course is applied to sun exposed roof slabs as needed. In hot day, the rods expand and move into the foam, compressing it as in fig.3 (a). In cool night the rods loosing heat shrink expanding the foam. Downward projection fixes capsule in concrete, allowing rod expansion with no stress on the concrete mortar as such and preventing cracks, adding years of life.
The device can be modified. For steel rods with ends bent as U arc, the modification as in fig 4, is used with a broad rectangular capsule 1, with a rectangular foam3, rectangular sleeve 6, is used. For ordinary bends a capsule as in fig. 5 can be used with a split elbow shaped capsule 1, a split foam 3 and two sleeves 6. For columns capsule can be fitted vertically on rod ends! The sleeve hole and slots adjust for different rod diameters, as the person wants. More external projections may be made on the capsule outside for fixing in the concrete. Shape may be changed too.
The device is made of plastic with the orifices, foam, sleeve incorporated as a unit or as separate segments easily assembled.
To use, the capsule is made from injection moulding with a transparent plastic say, acrylic, poly propylene, or pvc etc .The soft plastic foam bits are made as cylindrical pieces treated with antirust chemicals and enclosed in a plastic cover to hold the chemicals while setting. The sleeve may be made as another component by another die with a central hole for the steel rod.
It will be apparent to those skilled in the art that modifications to the invention described herein can readily be made without departing from the spirit of the invention. Protection is sought for all the subject matter described herein including any such modifications.
Advantages of the new invention:
1 .The thermal expansion stresses are decreased, with no cracking stress on the concrete.
2. Transparent body helps in easy application.
3. Marking on the capsule helps correct application by illiterates!
4. Anti-rusting chemicals further protect steel rods.
5. Life of concrete is longer.
6. Thermal stresses, biological corrosion are reduced 7.111iterate workers can fix it easily with the markings.
8. A cost effective device that tackles a physical problem and biological corrosion.

We Claim:
1 .A reinforced concrete thermal expansion protector comprising of a transparent plastic body, closed at one end, the other open end having a sleeve, the said sleeve having a hole for steel rod, the said capsule having on its inside a compressible foam with anti rust chemicals within a film cover, the said capsule has an external downward projection to fix, the said capsule is applied to steel rod ends and concrete poured over to set.
2. A reinforced concrete thermal expansion protector as claimed in claim 1, wherein the said capsule is made of transparent, strong plastic with a bold visible marking on its cylindrical surface for correct application on the steel rod ends.
3. A reinforced concrete thermal expansion protector as claimed in claim 1, wherein the capsule is a short cylinder, closed at one end, open at the other end, the said open end having a tight fitting sleeve to fit on the steel rod, the said capsule having the said compressible foam in its inside.
4. A reinforced concrete thermal expansion protector as claimed in claim 1, wherein the said short cylindrical foam has anti rust forming chemicals, the said foam being enveloped in a thin leak preventing plastic film cover.
5. A reinforced concrete thermal expansion protector as claimed in claim 1, wherein the said capsule has multiple external projections, one of which is down ward projected to support and hold the capsule on the said rods, in concrete setting.
6. A reinforced concrete thermal expansion as claimed in claim 1, wherein the said protector sleeve has a central hole for the steel rods, the said sleeve having radiating cuts to adjust for various rod diameter, the said sleeve fitting tightly to the said capsule after foam has been loaded.
7. A reinforced concrete thermal expansion protector as claimed in claim 1, wherein the said protecting chemicals are anti rust forming or rust forming bacterial killers.
8. A reinforced concrete thermal expansion protector as described in the specification and as illustrated by way of drawings



864-CHE-2004 AMENDED CLAIMS 30-01-2012.pdf

864-CHE-2004 AMENDED CLAIMS 11-04-2012.pdf


864-CHE-2004 CORRESPONDENCE OTHERS 30-01-2012.pdf

864-CHE-2004 CORRESPONDENCE OTHERS 11-04-2012.pdf

864-che-2004 abstract.pdf

864-che-2004 claims.pdf


864-che-2004 correspondence po.pdf


864-che-2004 description (complete).pdf

864-che-2004 drawings.pdf

864-che-2004 form 1.pdf

864-che-2004 form 18.pdf

864-che-2004 form 6.pdf

Patent Number 252700
Indian Patent Application Number 864/CHE/2004
PG Journal Number 22/2012
Publication Date 01-Jun-2012
Grant Date 28-May-2012
Date of Filing 26-Aug-2004
# Inventor's Name Inventor's Address
PCT International Classification Number E04C5/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA