Twoway slabs have two way bending unlike oneway slab. Oneway and twoway slabs university of asia pacific. Steps arrangement of series to communicating in between two floors is known as a stair. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3. The construction and design of concrete slabs on grade. The design process for the now withdrawn bs8110 design standard works slightly differently to that used in the new ec2 bs en 199211. Design of masonry short and long walls, columns and retaining walls. Calculate aspect ratio aspect ratio 2 longer spanshorter span 2. Design of two way slabs is 456 limit state method youtube. It is the only crosslinked 78 pex tubing on the market and its bending diameter is less than 20, making it easy to thread through floor joists. Twoway joist concrete slab floor waffle slab system.
This chapter describes in detail the various aspects of the concrete slab design procedure that is used by etabs when the american code aci 31814 aci. Aug 03, 2016 the design steps have been presented in the following question how do i degisn two way slab. Design of reinforced concrete structures ii twoway slabs. Design and analysis procedure direct design method operational steps figure 11. Twoway flat plate concrete floor system analysis and design the concrete floor slab system shown below is for an intermediate floor to be designed considering partition weight 20 psf, and unfactored live load 40 psf. Find depth of slab using deflection control criteria. Basic design criteria concentrically loaded d2 all sides c critical section for twoway shear b critical section for oneway shear a critical section for flexure outside face of concrete column or line midway between face of steel column and edge of steel base plate typical extent of footing typical d foundation design 8. Its virtue is its versatility which is its ability to be moulded to take any shape required for various structural forms. Flat plate concrete floor system does not use beams between columns or. Selection of the lateral resisting system and static design for gravity loads. Reinforced concrete design 1 design of slab examples.
The preferred method is method 3 for rectangular sections. Take spand 28 for simply supported slab and 32 for continuous slab. The entire process of structural planning and design requires not only imagination and conceptual thinking. An interior load condition is assumed for flexural analysis.
Design procedure steps for one way slab slab design steps. The recommendations derived from these and other studies vary from extremely light to extremely heavy. Where it forms end of a continuous slab, the length of centre of support shall be taken. Flat slab analysis, design and detailing pdf civil. The service live load is 100 psf and 4000 psi concrete is specified for use with steel with a yield stress equal to 60000 psi.
Selfweight of the column multiplies by number of floors. Minimum of clear span plus effective depth of slab center to centre distance between the supports. Twoway joist concrete slab floor waffle slab system analysis and design design the concrete floor slab system shown below for an intermediate floor with partition weight of 50 psf, and unfactored live load of 100 psf. Columns transfer vertical loads from a ceiling, floor or roof slab or from a beam, to a floor or foundation. A civil engineer must know all the aspects regarding the flat floor system. One way slab being supported on two opposite sides only leads to the structural action in single direction. Four long span composite slab specimens of 20 ft span length, using two different types of deck profiles, were built and tested experimentally. Nov 21, 2019 estimate and costing part 2 long wall short wall and centre line method civil engineering ssc je duration. Determine whether the slab geometry and loading allow the use of the direct design method as listed in ddm. It was actually the widespread use of the posttensioned slabonground which induced this interest in design procedure and in many studies of reported slab failures.
Please read the lauses mentioned in the video while solving the problem. Sep 02, 2011 design of reinforced concrete beams 45 m modular ratio the graphs in fig. The two classifications are oneway slab and twoway slab. Design of slab examples and tutorials by sharifah maszura syed mohsin example 1. Design of reinforced concrete beams 45 m modular ratio the graphs in fig.
See more ideas about stone slab, garden steps and landscape design. A series of steps between different levels or storeys of a building landing. Assume the thickness of slab take 4 cm per metre run of the span. Determine distribution of moments across the width of the slab. Reinforced concrete sk 33 section through slab showing stress due to moment. Design procedure of twoway slabs using aci moment coefficients. Oneway and twoway slabs oneway slabs transfer the imposed loads in one direction only. Design of short and long columns with axial and eccentric loading, design of isolated column footing. Distribute moments transverse at critical sections to column and middlestrip and if. In twoway slabs shorter direction strip carry greater %age of load. Grdslab concrete slab on grade analysis spreadsheet. Determine the thickness of the slab panel using previous article.
Analysis and design of slabs two way civil engineers pk. Feb 10, 2014 steps to be followed in the design of slab assuming suitable bearings not less than 10cm, find the span of the slab between the centers of bearings. They also carry bending moments about one or both of the crosssection axes. A 2 2area 2 a c 2 2 posttensioned concrete design table 11 list of symbols used in the aci 31808 code cp area enclosed by the outside perimeter of the section, in a g gross area of concrete, in a 2 l total area of longitudinal reinforcement to resist torsion, in a o area enclosed by the shear flow path, sqin a oh area enclosed by the centerline of the outermost closed. One way slab design how to design one way slab daily civil. Slabs are usually used in floor and roof construction. Following are the rcc slab design and detailing guidelines. Calculate positive and negative moments in the slab. Reinforced concrete slab design and detailing guidelines for depth of slab, loads on slab, reinforcement guide for oneway and twoway. The construction and design of concrete slabs on grade d. Oneway simply supported slab analysis and design of the slab similar to design of simply supported beam as indicate in the previous chapter. Also, minimum tubing is required to gain maximum heating results.
A six storey building for a commercial complex has plan dimensions as shown in figure 1. Both methods use the same procedure to divide the moments so found between the middle strip and column strips of the slab and the beams if any. The sequence of design steps of the ifbd procedure is the following. Dec 14, 2017 design of one way slab is covered in this video. Steps to be followed in the design of slab assuming suitable bearings not less than 10cm, find the span of the slab between the centers of bearings. Sep 03, 2011 reinforced concrete sk 33 section through slab showing stress due to moment. For those who do not know what are the des ign requirements of a slab. A reinforced concrete slab is built integrally with its supports and consists of equal span of 15 ft. Effective span for concrete slab design for simply supported slab. Practical steps in design of concrete buildings modelling. The design steps have been presented in the following question how do i degisn two way slab. This flexibility factor makes 78 pex much less prone to kinking than other 78 pex tubings. Select slab thickness to satisfy deflection and shear requirements.
Design of reinforced concrete structures ii twoway slabs 1 1. Find the following parameters for design moments in step 2 per unit width step 4 note. Introduction concrete slabs on grade are a very common type of concrete construction. Design of rectangular footings follows the same procedure as the design of. Here are the steps for the design procedure for one way slab in steps.
The slab has to carry a distributed permanent action of 1. Flat slab system is an important division of concrete floor system. The procedure of the design of oneway slab is the same as that of beams. Reinforced concrete design 1 design of slab examples and. Bending will take place in the two directions in a dishlike form. Good building design and construction handbook page 4 forewords yiping zhou director special unit for southsouth cooperation, undp good building design and construction. Slab design, bs 8110 slab design, how to determine ultimate load for slabs, how to check for deflection in slabs, how to calculate for dead load, how to calculate for lever arm, basics of slab design, how can i design a 2 way spanning slab. Design of slab for flexure 067 m unit width of slab. Before going to this topic, please read it there are two types of slab classification based on the direction of bending occurs in these slabs. What is slab, beam, column, and footing construction. Here, we have tried to gather various reading materials available in the web about flat slab floor system in one place. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near midspan.
The attachment of non structural elements is the responsibility of the architect or designer, unless specifically shown otherwise. The integral wearing surface is considered in the weight calculations. There are two types of slab classification based on the direction of bending occurs in these slabs. Analysis and design of steel deckconcrete composite slabs. Good building design and construction handbook page 3 purpose of the handbook this handbook is made to provide simple information to house owners, to house designers and builders, and building monitors to teach principles of good design and good construction in natural hazard prone areas. Simply supported one way slab a rectangular reinforced concrete slab is simplysupported on two masonry walls 250 mm thick and 3. Accordingly, main reinforcement is required in the two directions. Design of slab examples and tutorials by sharifah maszura syed mohsin. Handbook on good building, design and construction in the. Without significantly increasing the slab depth and weight compared to those of composite slabs with typical span, it was found that these long span slabs showed good performance under the load tests. These materials are originally located at different websites. Design of one way slabs as per is 456 worked step by step.
Floor slabs can range from a simple residential basement slab to a heavyduty industrial floor. The building is located in seismic zone iii on a site with medium soil. Oneway and twoway slabs oneway slabs transfer the imposed. The lateral loads are independently resisted by shear walls. Where reinforce ment quantities are not known, an assumption may be made of the per centage of reinforcement. Thoroughly studied, they will also guide on whether to. They may be supported on two opposite sides only fig. For this slab, panel a has two discontinuous exterior edges and two continuous interior edges, panel b has one discontinuous and three continuous edges, while the interior panel c has all edges continuous. Design step 4 design of deck prestressed concrete bridge design example task order dtfh6102t63032 43 for this example, a slab thickness of 8 in. Asce, secb course content slab on grades construction. That is, the concentrated post or wheel load is assumed to be well away from a free slab edge or corner.
The slab on grade worksheet assumes a structurally unreinforced slab, aci360type b, reinforced only for shrinkage and temperature. The results of the study show that the slab can be successfully used for residential buildings as it meets all the requirements and demands fewer materials. The design bending moments are zero at discontinuous ends, negative at continuous ends and positive at midspans. Concrete is arguably the most important building material which plays an important role in all building structures. Aci 360, design of slabsongrade, refers to this as a type b slab. The horizontal member which forms the upper surface of a step is called tread. Reinforced concrete slab design and detailing guide is456. D min 100mm for normal design and 125mm for earthquake resistant design. Select representative 1 m wide design stripstrips to span in the short direction, as shown in figure 8. Reinforced concrete slab design and detailing guidelines for depth of slab, loads on slab, reinforcement guide for oneway and twoway slabs as per is 456.