METHOD OF FORMING FLAT STRIP STEPPED SLAB FLOOR SYSTEM OF REINFORCED CONCRETE

Abstract

A system and a method for a reinforced concrete slab are disclosed. The system includes a plurality of column strips of a predefined thickness positioned on a plurality of columns, a plurality of transitional strips positioned adjacent to the plurality of column strips, whereby a thickness of the plurality of transitional strips comparatively less than the predefined thickness of the plurality of column strips, a central panel bound by the plurality of transitional strips, whereby the thickness of the central panel comparatively less than the thickness of the plurality of transitional strips and a plurality of column steps positioned in between the plurality of columns and the plurality of column strips.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention generally relates to a field of reinforced concrete slab construction. More particularly the present invention is related to a flat strip slab system.

BACKGROUND OF THE INVENTION

Beam-slab construction is the most popular floor system in reinforced concrete construction. The conventional systems suffer from drawbacks of increased shuttering and insitu works, extensive rebar fabrication, congestion of column beam junctions which are structurally critical. Failures during earthquakes amply demonstrate the weakness of beam slab floor system present in the conventional system.

Typically, flat slabs or flat plates are a common alternatives to the beam slab floor system. Due to uniform thickness, flat slabs demand higher slab thickness resulting into higher dead weight and higher consumption of material thereby increasing the cost of a construction.

Generally, flat plate slabs illustrated in FIG. 1 rests directly on top of the columns which support them, wherein the flat plate slabs are subjected to large bending moments, shearing forces and the effect of these high shears and flexural stress can cause failure by “punching” of the slab at the column-slab junction. Inappropriate distribution of the material in the flat plate slab system offers less resistance against lateral loading. Further flexural Stress distribution in flat slabs indicates highly under utilization and concentration of moment peaks at a limited zone around columns. Such peak concentration at a few locations making the flat plate slab susceptible for early failures.

Based on forgone experiences with the above systems, in order to overcome some design deficiencies, wide beam-slab system illustrated in FIG. 2 is developed. Wide beam and flat slab systems define column strip and rest of the slab area as depicted in FIG. 3. The series 1 represents flat slab system and series 2 represents wide beam system in FIG. 3. The improved wide beam and flat slab systems does not ensure smooth transfer of stresses and having a lower utility ratio as shown in FIG. 3.

A column supported concrete slab disclosed in U.S. Pat. No. 4,406,103 described controlling the diagonal shear cracks in the vicinity of the column zone by providing specific inserts in the both intent and content of the patent under reference is differ from the present invention in terms of transitional strips to enable normalizing the stress peaks between column strips and middle strips accordingly the present invention leads to stepped slab, whereas stepped slab of linear strips forming closed boundaries. The embodiments described in U.S. Pat. No. 4,406,103 in concrete deals with a conventional flat slab which includes uniform thickness. Flat slab requires higher slab thickness resulting into higher dead weight and higher consumption of material thereby increasing the cost of a construction.

Hence there exists a need for a system and a method to achieve an optimized slab system for an optimal distribution of stresses, possible improvement under lateral loading and efficient utilization of material in a reinforced concrete slab.

BRIEF SUMMARY OF THE INVENTION

A system and a method for a reinforced concrete slab are disclosed. According to a first aspect of the present invention, a system for a reinforced concrete slab includes a plurality of column strips of a predefined thickness positioned on a plurality of columns.

According to the first aspect of the present invention, the system for a reinforced concrete slab includes a plurality of transitional strips positioned adjacent to the plurality of column strips, whereby a thickness of the plurality of transitional strips comparatively less than the predefined thickness of the plurality of column strips.

According to the first aspect of the present invention, the system for a reinforced concrete slab includes a central panel bound by the plurality of transitional strips, whereby the thickness of the central panel comparatively less than the thickness of the plurality of transitional strips.

According to a second aspect of a present invention, a system for a reinforced concrete slab is disclosed. According to the second aspect of the present invention, the system for a reinforced concrete slab includes a plurality of column steps positioned in between the plurality of columns and the plurality of column strips.

According to a third aspect of a present invention, a method for a reinforced concrete slab is disclosed. According to the third aspect of the present invention, the method for a reinforced concrete slab includes positioning a plurality of column strips of predefined thickness on a plurality of columns.

According to the third aspect of the present invention, the method for a reinforced concrete slab includes positioning a plurality of transitional strips adjacent to the plurality of column strips, whereby a thickness of the plurality of transitional strips comparatively less than the predefined thickness of the plurality of column strips. A step of varying the thickness of the strips at a predefined regular interval enables the optimal distribution of stresses in the reinforced concrete slab.

According to the third aspect of the present invention, the method for a reinforced concrete slab includes bounding a central panel by the plurality of transitional strips, whereby the thickness of the central panel comparatively less than the thickness of the plurality of transitional strips.

According to a fourth aspect of a present invention, a method for a reinforced concrete slab is disclosed. According to the fourth aspect of the present invention, the method for a reinforced concrete slab includes positioning a plurality of column steps in between the plurality of columns and the plurality of column strips.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments, in conjunction with the accompanying drawings, wherein like reference numerals have been used to designate like elements, and wherein:

FIG. 1 is a diagram depicting a typical part plan of a conventional flat slab system.

FIG. 2 is a diagram depicting a typical part plan of a conventional wide beam slab system.

FIG. 3 is a diagram depicting a graphical representation of utility ratio in conventional slab systems.

FIG. 4 is a diagram depicting a typical part plan of a flat strip slab system.

FIG. 5 is a diagram depicting a typical part plan of a flat strip slab system with multiple column steps.

FIG. 6 is a diagram depicting a cross sectional view of a flat strip slab system through a central panel.

FIG. 7 a is a diagram depicting a cross sectional view of a flat strip slab system with multiple column steps.

FIG. 7 b is a diagram depicting a cross sectional view of a column steps

FIG. 8 is a diagram depicting an overview of a flat strip slab system.

FIG. 9 is a diagram depicting a graphical representation of utility ratio in different slab systems.

DETAILED DESCRIPTION OF THE INVENTION

It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The present disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

The use of “including”, “comprising” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. Further, the use of terms “first”, “second”, and “third”, and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

Exemplary embodiments of the present invention are directed towards a system and a method for a reinforced concrete slab. According to a first aspect of a present invention, a system for the reinforced concrete slab includes a plurality of column strips of a predefined thickness positioned on a plurality of columns.

According to the first aspect of the present invention, the system for a reinforced concrete slab includes a plurality of transitional strips positioned adjacent to the plurality of column strips, whereby a thickness of the plurality of transitional strips comparatively less than the predefined thickness of the plurality of column strips.

According to the first aspect of the present invention, the system for a reinforced concrete slab includes a central panel bound by the plurality of transitional strips, whereby the thickness of the central panel comparatively less than the thickness of the plurality of transitional strips.

According to a second aspect of a present invention, a system for a reinforced concrete slab is disclosed. According to the second aspect of the present invention, the system for a reinforced concrete slab includes a plurality of column steps positioned in between the plurality of columns and the plurality of column strips.

According to a third aspect of a present invention, a method for a reinforced concrete slab is disclosed. According to the third aspect of the present invention, the method for a reinforced concrete slab includes positioning a plurality of column strips of predefined thickness on a plurality of columns.

According to the third aspect of the present invention, the method for a reinforced concrete slab includes positioning a plurality of transitional strips adjacent to the plurality of column strips, whereby a thickness of the plurality of transitional strips comparatively less than the predefined thickness of the plurality of column strips. A step of varying the thickness of the strips at a predefined regular interval enables the optimal distribution of stresses in the reinforced concrete slab.

According to the third aspect of the present invention, the method for a reinforced concrete slab includes bounding a central panel by the plurality of transitional strips, whereby the thickness of the central panel comparatively less than the thickness of the plurality of transitional strips.

According to a fourth aspect of a present invention, a method for a reinforced concrete slab is disclosed. According to the fourth aspect of the present invention, the method for a reinforced concrete slab includes positioning a plurality of column steps in between the plurality of columns and the plurality of column strips.

Referring to FIG. 4 is a diagram 400 depicting a typical part plan of a flat strip slab system. In accordance with a non limiting exemplary embodiment of the present invention, a system for a reinforced concrete slab includes multiple columns 402a, 402b, 402c and 402d, multiple column strips 404a, 404b, 404c and 404d, multiple transitional strips 406a, 406b, 406c and 406d and a central panel 408 bound by multiple transitional strips 406a, 406b, 406c, 406d.

In accordance with an exemplary embodiment of the present invention, the column strips 404a, 404b, 404c and 404d of a predefined thickness are positioned on the columns 402a, 402b, 402c and 402d. The transitional strips 406a, 406b, 406c and 406d are positioned adjacent to the column strips 404a, 404b, 404c and 404d. The thickness of the transitional strips 406a, 406b, 406c and 406d is comparatively less than the predefined thickness of the column strips 404a, 404b, 404c and 404d. The central panel 408 is bounded by the transitional strips 406a, 406b, 406c and 406d. The thickness of the central panel 408 is comparatively less than the thickness of the transitional strips 406a, 406b, 406c and 406d.

According to a non limiting exemplary embodiment of the present invention, the thickness of the slab is varied from the column strips 404a, 404b, 404c and 404d to the central panel 408 for enabling the optimal distribution of stresses in the reinforced concrete slab and also for an efficient utilization of the structural sections provided on the reinforced concrete slab.

Referring to FIG. 5 is a diagram 500 depicting a typical part plan of a flat strip slab system with multiple column steps. In accordance with a non limiting exemplary embodiment of the present invention, a system for a reinforced concrete slab includes multiple columns 502a, 502b, 502c and 502d, multiple column steps 504a, 504b, 504c and 504d, multiple column strips 506a, 506b, 506c and 506d, multiple transitional strips 508a, 508b, 508c and 508d and a central panel 520 bound by the multiple transitional strips 508a, 508b, 508c and 508d.

Referring FIG. 6 is a diagram 600 depicting a cross sectional view of a flat strip slab system through central panel. In accordance with a non limiting exemplary embodiment of the present invention, the cross sectional view of the flat strip slab system depicts multiple columns 602a and 602b, multiple column strips 604a and 604b, multiple transitional strips 606a and 606b and a central panel 608.

In accordance with an exemplary embodiment of the present invention, the column strips 604a and 604b of a predefined thickness are positioned on the columns 602a and 602b. The transitional strips 606a and 606b are positioned adjacent to the column strips 604a and 604b. The thickness of the transitional strips 606a and 606b is comparatively less than the predefined thickness of the column strips 604a and 604b. The central panel 608 is bound by the transitional strips 606a and 606b. The thickness of the central panel 608 is comparatively less than the thickness of the transitional strips 606a and 606b.

Referring to FIG. 7a is a diagram 700a depicting a cross sectional view of a flat strip slab system with multiple column steps through a column strip. In accordance with a non limiting exemplary embodiment of the present invention, the cross sectional view of a flat strip slab with multiple column steps depicts multiple columns 702a and 702b, multiple column steps 704a, 704b and a column strip 706.

In accordance with an exemplary embodiment of the present invention, the columns strip 706 of a predefined thickness is positioned on columns 702a and 702b. The multiple column steps 704a and 704b are positioned in between the columns 702a and 702b and the column strip 706 to achieve an optimal distribution of stresses in the reinforced concrete flat strip slab.

Referring to FIG. 7b is a diagram 700b depicting a cross sectional view of a column steps. In accordance with a non limiting exemplary embodiment of the present invention, the cross sectional view of a column steps depicts a column 702, a column steps 704, and a slab cast portion 708.

In accordance with an exemplary embodiment of the present invention, the column steps 704 is positioned in between the column 702 and the slab cast portion 708 to achieve the optimal distribution of stresses in the reinforced concrete flat strip slab. The slab cast portion 708 is positioned over column steps 704.

Referring FIG. 8 is a diagram 800 depicting an overview of a flat strip slab system. In accordance with a non limiting exemplary embodiment of the present invention, the overview of a flat strip slab system depicts a column strip 802, a transitional strip 804 and a central panel 806.

In accordance with an exemplary embodiment of the present invention, the column strip 802 of a predefined thickness is positioned on the columns. The transitional strip 804 is positioned adjacent to the column strip 802. The thickness of the transitional strip 804 is comparatively less than the predefined thickness of the column strip 802. The central panel 806 is bound by the transitional strips 804. The thickness of the central panel 806 is comparatively less than the thickness of the transitional strip.

According to a non limiting exemplary embodiment of the present invention, the thickness of the slab is varied from the column strips 802 to the central panel 806 for enabling the optimal distribution of stresses in the reinforced concrete slab and for an efficient utilization of the structural sections provided.

Referring FIG. 9 is a diagram 900 depicting a graphical representation of utility ratio in different slab systems. In accordance with a non limiting exemplary embodiment of the present invention, the graphical representation of ratio in different slab systems is depicted in series 1, series 2 and series 3.

In accordance with an exemplary embodiment of the present invention, utility ratio is taken as a ratio of applied average moment to moment of resistance of section under reference using consistence units as shown in a flat strip slab system as ability to achieve higher utility ratio against to flat slab system and wide beam system.

In accordance with an exemplary embodiment of the present invention, series 1 represents a flat strip slab system, series 2 represents a flat slab system and series 3 represents a wide beam system. Span location taken along x-axis and the utility ratio is taken along Y-axis and a graph is plotted for the flat strip slab system, the flat slab system and wide beam system. The graph shows higher utility ratio in the flat strip slab system when compared with the flat slab system and the wide beam system. The plot between the span location 1 and the span location 3 represents the utility ratio of a column strip, the plot between the span location 3 and the span location 4 represents the utility ratio of a transitional strip, the plot between the span location 4 and the span location 10 represents the utility ratio of a middle strip, the plot between the span location 10 and the span location 11 represents the utility ratio of the transitional strip and the plot between the span location 11 and the span location 13 represents the utility ratio of the column strip in the flat strip slab system, the flat slab system and the wide beam system.

According to a non limiting exemplary embodiment of the present invention, the purpose of transitional strip in the flat strip slab system is to smoothen out stress peaks between column strip and middle strip. This feature make rove appropriate to improve lateral force resisting ability of slabs particularly an encountered with rigid shear walls where stress peaks are very high.

As will be appreciated by a person skilled in the art the present invention provides a variety of advantages. Firstly, the invention is designed for all possible load cases of both gravity and lateral loads. Secondly, the invention provides an efficient stress leveling with optimal distribution of stresses. Thirdly, the flat strip slabs consumes less amount of concrete compared to the other conventional systems. Fourthly, the invention provides an economical and elegant alternative to the conventional floor systems.

While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

Claims

1. A reinforced concrete slab system, comprising: a plurality of column strips of a predefined thickness positioned on a plurality of columns;a plurality of transitional strips positioned adjacent to the plurality of column strips, whereby a thickness of the plurality of transitional strips comparatively less than the predefined thickness of the plurality of column strips; anda central panel bound by the plurality of transitional strips, whereby the thickness of the central panel comparatively less than the thickness of the plurality of transitional strips.

2. A system for a reinforced concrete slab, comprising: a plurality of column strips of a predefined thickness positioned on a plurality of columns;a plurality of transitional strips positioned adjacent to the plurality of column strips, whereby a thickness of the plurality of transitional strips comparatively less than the predefined thickness of the plurality of column strips;a central panel bound by the plurality of transitional strips, whereby the thickness of the central panel comparatively less than the thickness of the plurality of transitional strips; anda plurality of column steps positioned in between the plurality of columns and the plurality of column strips;

3. A method for a reinforced concrete slab, comprising: positioning a plurality of column strips of predefined thickness on a plurality of columns;positioning a plurality of transitional strips adjacent to the plurality of column strips, whereby a thickness of the plurality of transitional strips comparatively less than the predefined thickness of the plurality of column strips; andbounding a central panel by the plurality of transitional strips, whereby the thickness of the central panel comparatively less than the thickness of the plurality of transitional strips.

4. The method of claim 4, wherein a step of varying the thickness of the strips at a predefined regular interval enables the optimal distribution of stresses in the reinforced concrete slab.

5. A method for a reinforced concrete slab, comprising: positioning a plurality of column strips of predefined thickness on a plurality of columns;positioning a plurality of transitional strips adjacent to the plurality of column strips, whereby a thickness of the plurality of transitional strips comparatively less than the predefined thickness of the plurality of column strips;bounding a central panel by the plurality of transitional strips, whereby the thickness of the central panel comparatively less than the thickness of the plurality of transitional strips; andpositioning a plurality of column steps in between the plurality of columns and the plurality of column strips.