Development of Some Design Charts for Slab, Beam, Column and Flat Plate

Transcription

1 Banglavision ISSN: X Vol. 13 No. 1 January 2014 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.

2 118 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.

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5 Development of Some Design Charts for Slab, Beam, Column and Flat Plate 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.

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7 Development of Some Design Charts for Slab, Beam, Column and Flat Plate To develop design chart for the flat plate for fixed span ratios but different panel areas.

8 124 Banglavision Vol. 13, No. 1, 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.

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10 126 Banglavision Vol. 13, No. 1, 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 f y.

11 Conclusion Development of Some Design Charts for Slab, Beam, Column and Flat Plate 127 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 f y = 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,13 th edition, McGraw-Hill, New York. Nilson, Arthur. H, Darwin, David and Dolan Charles. W. (2003). Design of Concrete Structures, 7 th 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, 2 nd edition, Farah Publishers Das, Susil Kumar, (2005). "Treasure of R.C.C. Design"