DESC:
FIELD OF INVENTION

The present invention relates to a Thermo Mechanically Treated (TMT) bar with improved surface rib pattern profile for high adherence, particularly for reinforcements for concrete. More particularly, the present invention relates to developing TMT bars having enhanced root strength in transverse rib throughout the bar and extra gripping and enhancing fatigue life while retaining bond strength of said TMT bars by improving surface rib profiles.

BACKG ROUND OF THE INVENTION

The use of Thermo mechanically treated steel reinforcement bars is well known in RCC application. It has also been experienced in the art that considering the safety aspect of such construction, there had been a need to develop steel materials with even higher bond strength with same section for the TMT bars to suit application in RCC.

In the prior art an Indian application IN197/KOL/2010 discloses an improved reinforcing bar (REBAR) for reinforced concrete constructions and reinforced concrete structures comprising a high strength material, a circular or oval or elliptical cross section of said bar; deformation of the axis of the bar in specific plane (s).

Reference has also been made to US7624556B2, the threaded deformed reinforcing bar disclosed herein, is used in concrete construction and may be easily connected to other threaded deformed reinforcing bars by an internally threaded coupler. The threaded deformed reinforcing bar has a continuous spiral thread upon at least a portion of its length which engages the internally threaded coupler. The continuous spiral thread upon the deformed reinforcing bar is formed by eliminating portions of longitudinal ribs that are formed upon the reinforcing bar during manufacturing. This process for forming the threaded deformed reinforcing bar is less expensive than conventional processes.

IN 254979 discloses a process of manufacturing a metal bar having cross ribs on both front and back surfaces of the bar, the front and back surfaces being intersected by straight ribs passing through the apex of individual cross on both of the front and back surface.

IN 3713/Del/2013 discloses method of manufacturing TMT Bars with patterns of double transverse ribs, wherein in one preferred embodiment of TMT bar with pattern of double transverse ribs made by the said method herein, first angle for first pattern of transverse ribs is preferably selected and created using said Die-sets in the range of 69 degrees to 71 degrees with respect to the longitudinal rib therein and the second pattern of transverse ribs is created in the range of 53 degrees to 55 degrees.

Therefore, there remains a need for an advance rib design for the TMT bars to enhance extra root strength in transverse rib throughout the bar and provide extra gripping and enhancing fatigue life while retaining bond strength.

SUMMARY OF THE INVENTION

The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention.

It is thus the intent of the present invention to overcome the limitation of the existing TMT bars used for RCC structures by developing a new surface rib pattern profile of steel TMT rebars capable of providing enhance extra root strength in transverse rib throughout the bar and extra gripping and enhancing fatigue life while retaining bond strength.

The first aspect of present invention is to provide an improved surface rib pattern profile thermos mechanically treated (TMT) bar comprising:
a core, said core defining an outer surface and a central axis therethrough,
two parallel longitudinal ribs vertically spaced apart and extending throughout the length of the bar,
at least two sets of first transverse ribs on both front and back surfaces of the bar; said at least two sets of first transverse ribs being longitudinally spaced apart and disposed within the vertical space between said two parallel longitudinal ribs, inclined relative to the central axis of the bar;
at least one second transverse rib on both front and back surfaces of the bar, disposed within the longitudinal space between at least two sets of first transverse ribs;
wherein said at least two sets of first transverse ribs have a predefined angle;
characterized in that the at least one second transverse rib has an inclined parallelogram structure such that one of the diagonals of the parallelogram coincides the central axis of the bar.

The improved surface profile of present invention gives the capability to fight against natural disasters, enhances extra root strength in transverse rib throughout the bar, gives extra gripping and enhanced fatigue life while retaining bond strength. While maximum conventional TMT bars fails in fatigue at root of the transverse rib, the TMT bars with the improved surface profile of present invention always fight against of earthquake. In case of present invention, Passive Film forms throughout the circumference of bar to protect from corrosion. Further, the improved surface profile of present invention maintains homogeneity in its profile of transverse rib, physical appearance, chemical composition and engineering properties throughout the entire length of the TMT bars. Further, the improved surface profile of present invention has rich ductile property to reduce the speed of structure breaking.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

The above and other aspects, features and advantages of the embodiments of the present disclosure will be more apparent in the following description taken in conjunction with the accompanying drawings, in which:

Figure 1 (a-b) shows improved surface rib profile as per present invention, (a) reading back view of the TMT bar, (b)rolling back view of the TMT bar as per present invention

Figure 2 illustrates different view of the ribs and different parameters for calculation.

Figure 3 shows the perspective view of the improved surface rib profile as per present invention.

DETAILED DESCRIPTION OF INVENTION

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure and their equivalents.

It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

The terminology used herein is for the purpose of describing particular various embodiments only and is not intended to be limiting of various embodiments. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising" used herein specify the presence of stated features, integers, steps, operations, members, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, members, components, and/or groups thereof. Also, Expressions such as "at least one of," when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

The present disclosure will now be described more fully with reference to the accompanying drawings, in which various embodiments of the present disclosure are shown. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the various embodiments set forth herein, rather, these various embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the present disclosure. Furthermore, a detailed description of other parts will not be provided not to make the present disclosure unclear. Like reference numerals in the drawings refer to like elements throughout.

The subject invention lies in a Thermo Mechanically Treated (TMT) bar with improved surface rib pattern profile for higher adherence particularly for reinforcement for concrete. The TMT bars having the surface rib pattern of present invention have enhanced root strength in transverse rib throughout the bar and extra gripping and enhanced fatigue life while retaining bond strength of said TMT bars by improving surface rib profiles.

Figure 1 (a-b) illustrates an embodiment of present invention which relates to an improved surface rib pattern profile thermos mechanically treated (TMT) bar comprising:
a core, said core defining an outer surface and a central axis therethrough,
two parallel longitudinal ribs vertically spaced apart and extending throughout the length of the bar,
at least two sets of first transverse ribs on both front and back surfaces of the bar; said at least two sets of first transverse ribs being longitudinally spaced apart and disposed within the vertical space between said two parallel longitudinal ribs, inclined relative to the central axis of the bar;
at least one second transverse rib on both front and back surfaces of the bar, disposed within the longitudinal space between at least two sets of first transverse ribs;
wherein said at least two sets of first transverse ribs have a predefined angle;
characterized in that the at least one second transverse rib has an inclined parallelogram structure such that one of the diagonals of the parallelogram coincides the central axis of the bar.

In a preferred embodiment, said predefined angle is in range of 57-60°.

In one of the embodiments of present invention, where such bar has a nominal diameter D; a distance between centers of consecutive first transverse ribs “L”; a rib height of transverse ribs “h”, a rib height of longitudinal ribs “h1”, a pitch of transverse ribs and a rib area “A”.

According to another embodiment of present invention, the TMT may have Nominal bar diameter (D) in the range of 8 mm to 32 mm.

According to yet another embodiment of present invention, each of said at least two sets of first transverse ribs comprises at least one transverse rib.

According to further embodiments of present invention, each of said at least two sets of first transverse ribs comprises at least two transverse ribs.

According to further embodiments of present invention, each of said at least two sets of first transverse ribs comprises at least three transverse ribs.

According to another embodiment of present invention, said parallelogram includes rhombus, trapezoid, diamond-shaped and like.

The dimensions of different parameters of present invention have been tabulated below:


The advantages of present invention are as follows:

1. The improved surface profile of present invention gives the capability to fight against natural disasters.

2. The improved surface profile of present invention enhances extra root strength in transverse rib throughout the bar.

3. The improved surface profile of present invention gives extra gripping and enhancing fatigue life while retaining bond strength.

4. Maximum TMT bars failed in fatigue at root of the transverse rib, in case of present invention always fight against of earthquake.

5. Passive Film form throughout the circumference of bar to protect from corrosion.

6. The improved surface profile of present invention maintains homogeneity in its profile of transverse rib, physical appearance, chemical composition and engineering properties throughout the entire length of the TMT bars.

7. The improved surface profile of present invention has rich ductile property to ensure that the speed of structure breaking would not be too fast.
,CLAIMS:1. An improved surface rib pattern profile thermos mechanically treated (TMT) bar comprising:
a core, said core defining an outer surface and a central axis therethrough,
two parallel longitudinal ribs vertically spaced apart and extending throughout the length of the bar,
at least two sets of first transverse ribs on both front and back surfaces of the bar; said at least two sets of first transverse ribs being longitudinally spaced apart and disposed within the vertical space between said two parallel longitudinal ribs, inclined relative to the central axis of the bar;
at least one second transverse rib on both front and back surfaces of the bar, disposed within the longitudinal space between at least two sets of first transverse ribs;
wherein said at least two sets of first transverse ribs have a predefined angle;
characterized in that the at least one second transverse rib has an inclined parallelogram structure such that one of the diagonals of the parallelogram coincides the central axis of the bar.

2. The improved surface rib pattern profile thermos mechanically treated (TMT) bar as claimed in claim 1, wherein said predefined angle is in range of 57-60°.

3. The improved surface rib pattern profile thermos mechanically treated (TMT) bar as claimed in claim 1, wherein the TMT comprises Nominal bar diameter (D) in the range of 8 mm to 32 mm.

4. The improved surface rib pattern profile thermos mechanically treated (TMT) bar as claimed in claim 1, each of said at least two sets of first transverse ribs comprises at least one transverse rib.

5. The improved surface rib pattern profile thermos mechanically treated (TMT) bar as claimed in claim 1, each of said at least two sets of first transverse ribs comprises at least two transverse ribs.

6. The improved surface rib pattern profile thermos mechanically treated (TMT) bar as claimed in claim 1, each of said at least two sets of first transverse ribs comprises at least three transverse ribs.

7. The improved surface rib pattern profile thermos mechanically treated (TMT) bar as claimed in claim 1, wherein said parallelogram includes rhombus, trapezoid, diamond-shaped and like structure.