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Development of Some Design Charts for Slab, Beam, Column and Flat Plate
Nitish Ranjan Gaine∗
Nazma Khatun∗∗
Suite Kumar∗∗∗
Abstract
The aim of this project is to develop some design charts of slab, beam, column
and flat plate. In this project some equations were also developed from design
charts. These help a design engineer to design instantly and approximately of
those components without any calculation. Moreover, the developed spreadsheets
can be used for required design information. Design charts of slab, beam, column
and flat plate as well as equations with respect to various areas span length,
panel ratios, material properties and superimposed loads were developed in this
project. Most of the curves from correlations are found two degree for beams and
two way slabs, some curves of one way slabs and columns are linear. Design of
these components requires much time. But if some design charts are available it is
easy to design these important components. Moreover, it is easy to carry these
charts everywhere.
Keywords: design charts, span length, panel ratios, superimposed loads, material properties.
Introduction
For various civil engineering designs different software are widely used now a days. But in
any case where computer is not provided or time is not sufficient for manual design, design
charts may help a civil engineer to design slab, beam, column etc. instantly and
approximately. The equations developed from design of various components will help an
engineer as a guide to solve the structural design for varied size, shape, etc.In this study it
will have to establish some design charts for some structural member, namely slab, beam,
column and flat plate.
∗
Khulna University of Engineering and Technology, Khulna, Bangladesh. ∗∗
Khulna University of Engineering and Technology, Khulna, Bangladesh. ∗∗∗
Chittagong University of Engineering and Technology, Chittagong, Bangladesh.
Banglavision ISSN: 2079-567X
Vol. 13 • No. 1 • January 2014
118 Banglavision Vol. 13, No. 1, 2014
“Design is the determination of the general shape and all specific dimensions of a particular
structure so that it will perform the function for which it is created and will safely withstand
the influences, which will act on it throughout its useful life”.
“In reinforced concrete construction, slabs are used to provide flat, useful surfaces. A
reinforced concrete slab is a broad, flat plate, usually horizontal, with top and bottom
surfaces parallel or nearly so. It may be supported by reinforced beams, by masonry or
reinforced concrete wall, by structural steel member, directly by columns or continuously by
the ground”. Slabs may be supported on two opposite side only in which case the structural
action of the slab is essentially one way, the loads being carried by the slab in the direction
perpendicular to the supporting beams. If the ratio of length to width of one panel is larger
than 2, most of the load is carried in the short direction to the supporting beams and one way
action is obtained, even through supports are provided on all sides. There may be beam all
sides so that two way slab action is obtained. Normally the ratio of length to width of one
panel is smaller than 2.Concrete slabs may in some cases be carried directly by columns
without the use of beams or girders. Such slabs are described as flat plate and are commonly
used where spans are not large and loads not particularly heavy.Reinforced concrete beams
are non-homogeneous in that they are made of two entirely different materials. This type of
beam is composed of concrete in which steel bars are embedded. In this beam concrete takes
up the compressive stresses whereas the steel resists the tensile stresses produced in the beam
during bending. In a reinforced concrete beam, the concrete adheres firmly to the steel.
Column is defined as concrete compression member. Its unsupported length is more than
three times the least dimension of the cross-section. Particularly columns are members
subjected to both direct load and moment.
A flat-plate floor is a two-way slab system consisting of a uniform slab that rests directly on
columns and does not have beams or column capital .In this case the column tends to punch
through the slab, producing diagonal tensile stresses .Therefore a general increase in the slab
thickness is required or special reinforcement is used.
Results and discussion
2.1 To develop design chart for the one way slab (4 side-supported) with; (a) The variation of
Various areas for constant span ratio (L/B). (b) The variation of short span for constant
long span.
Development of Some Design Charts for Slab, Beam, Column and Flat Plate 121
2.2 To develop design chart for the two way slab for various span ratio (B/L) with constant
long span, when (a) all side continuous.(b)one long and two short side continuous. (c)one
long and one short side continuous. (d)one short and two long side continuous.
Development of Some Design Charts for Slab, Beam, Column and Flat Plate 123
2.3 To develop design chart for the flat plate for fixed span ratios but different panel areas.
124 Banglavision Vol. 13, No. 1, 2014
2.4 Design chart for column (a) For 10”, 12”, 14” and 16” dia. circular columns at different
loadings and constant steel ratio.(b) For 10”x10”, 12”x10”, 12”x12” and 14”x12”
rectangular columns at different loadings and constant steel ratio.
126 Banglavision Vol. 13, No. 1, 2014
2.5 Design chart for the beam (a) with the variation of span lengths for constant x-section. (b)
with the variation of f’c for constant fy.
Development of Some Design Charts for Slab, Beam, Column and Flat Plate 127
Conclusion
Design charts may help a civil engineer to design slab, beam, column etc. instantly and
approximately when time is not sufficient. I had prepared design charts only for four cases
though there has nine cases and I had prepared design charts considering f′c = 3ksi & 40ksi
and fy = 40 ksi & 60 ksi for the two way slab. So another design charts can be prepared for
the rest. The charts can be used as ready reference for approximate design of slab, beam,
column and flat plate.
Acknowledgement
The authors would like to express their gratefulness to the Department of Civil Engineering,
Khulna University of Engineering and Technology, Bangladesh for co-operation during the
period of works.
References:
Arthur. H, Darwin, David and Dolan Charles. W. (2003). “Design of Concrete Structures”,13th
edition, McGraw-Hill, New York.
Nilson, Arthur. H, Darwin, David and Dolan Charles. W. (2003). “Design of Concrete
Structures”, 7th
edition, McGraw-Hill, New York.
Hassoun, M. Nadim, (1998). “Stuctural Concrete”, ADDISON-WESLEY
Khan, Abul Feraz. Rahman, Engr. Shaifur, (1993) ”REINFORCED CONCRETE MANUAL AND
BUILDING PLAN”, 2nd
edition, Farah Publishers
Das, Susil Kumar, (2005). "Treasure of R.C.C. Design"