The factory produces hordi blocks from polystyrene which is available in all dimensions starting from 1020 kg. Reinforced concrete sk 33 section through slab showing stress due to moment. Crcm manual 4 crcm means concrete rib construction method, the word method, can create confusion, because the icc ibc uses such word in the section 1701. Now here i need to clarify that this article will not treat waffle slab foundation which is another building element used in high cyclonic and windy areas but that is out of the scope of this article. Analysis and design of slabs one way civil engineers pk. Concrete rib construction method, crcm uses the engineering technology to design the elements structurals to handle the loads originated by climatic and or geographical location of the project. The design procedure includes determini ng slab thickness based on moving live loads and then checking adequacy of slab thickness for stationary live load. As the nature of these blocks is hollow with greater resistance, they are generally used in creating roofs which are more comfortable under a hot climate. In case of hollow block slab voided blocks are placed to reduce the total weight of the slab. The slab system used is limited to hordi slabs and solid slabs on beams.
In these tests, screws of various sizes and thread design were evaluated for resistance to withdrawal when pulled out of the face of diamond snapties. 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. I have used the word flat slab and by that i mean the slab that has leveled surface from both top and soffit. The espac precast ribhordi roof system is intended primarily for houses, low rise. Ribbed slabs oneway joists introducing voids to the soffit of a slab reduces dead weight and increases the efficiency of the concrete section. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3. Department of mechanics, materials and structures english. Structural design practice for residential buildings in. Polystyrene slab hourdi slab concrete slab ceiling. Pdf in the design of reinforcedconcrete buildings, solid and lightweight hollow block slabs are commonly. Dec 09, 2006 the factory produces hordi blocks from polystyrene which is available in all dimensions starting from 1020 kg. Recommendations for finite element analysis for the design of. According to the way loads are transferred to supporting beams and columns, slabs are classified into two types. The design procedure set forth in that publication had at that time been in use by the author for about 15 years.
Find the following parameters for design moments in step 2 per unit width step 4 note. Composite slab worked example 1 made by sssr date 140500 structural steel design project calculation sheet checked by pu date 080800 check the adequacy of the continuous composite profiled deck slab with spans of 3. Al manaratain produces hourdi roof rak and light weight blocks in 7, 9. A civil engineer must know all the aspects regarding the flat floor system. In order to simplify the analysis and to be able to use the superposition. Twoway slabs have two way bending unlike oneway slab. Chip off the loose concrete slurry at edges of rib beams and polystyrene hourdi. Effective span of slab shall be lesser of the two 1. Oct 21, 2016 csi etabs 2016flat slab design, strip design and punching shear check duration. Designing a one way ribbed concrete joist floor system per. The distribution of slab moments into column strips and middle strips is to be made in the same manner as specified in direct design method. Slabs are usually used in floor and roof construction. Reference 5 focused on analysis of twoway ribbed slabs with.
L center to center distance between the support b depth of slab. The hourdi blocks manufactured by al manaratain is used to create floors and roofs. The appropriate ratio may be obtained from table 3. Genrally construction of building members like coulmns beams and slabss etc. Pdf investigating the effect of solid and lightweight hollow block.
Only the conditions at the centre of the span in the width of slab under consideration should be considered to influence deflection. You have asked this question because waffle slab is not that common throughout the world. Please practice handwashing and social distancing, and check out our resources for adapting to these times. Hordy slabhollow block slab hollow blocks are used to fill portions of the slab thickness. The design procedure separately incl udes determining thickness of slab under wall load. What is waffle slab and hordy slabhollow block slab. The clear distance between ribs cannot be greater than 30 inches per aci code 31811 section 8.
Bending will take place in the two directions in a dishlike form. Analysis of two way ribbed and waffle slabs with hidden beams. In design of twoway slabs, the possibility to redistribute the load between the different loading directions is used in plastic design methods. Design of slab for flexure 067 m unit width of slab. Analyze and design flat slab or waffle slab floors. Chapter 3 design of rectangular beams and oneway slabs 12 h a 12 strip in a simply supported one way sl ab h. Tests showed only slight variation in the force required to remove a variety of. The design of composite slabs and beams is discussed in detail in relation to the eurocodes and bs 5950. The strip may have up to 20 spans and may have cantilevers at the ends. As support for these types of applications, dsf conducted numerous screw withdrawal tests. Reinforced concrete slab design and detailing guide is456. In twoway slabs shorter direction strip carry greater %age of load. Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems. Experiments on fibre reinforced concrete twoway slabs.
Concrete floor slabs on grade are subjected to a varie ty of loads and loading conditions. The saving of materials tends to be offset by some. But crcm uses concrete a material used more than 3,000. In addition to general ultimate and serviceability limit state design issues, practical design considerations such as the formation of holes in the slab, support details, fire protection, and attachments to the slab are discussed. Rectangular beams and oneway slabs page 5 of 9 maximum permissible steel ratio, max an overreinforced beam will fail in a brittle manner while an underreinforced beam will.
We would be restricting ourselves to understand the waffle slab used as roof. Shopdesign drawing to be strictly complied with at the site. Rectangular beams and oneway slabs page 3 of 9 design of rectangular beams and oneway slabs continued a. Chapter 3 design of rectangular beams and oneway slabs 12. Csi etabs 2016flat slab design, strip design and punching shear check duration. Remove all minor protrusions, nails, deposits, masking tapes, paint marks p. Dec 27, 2016 dec 27, 2016 hordy slab hollow block slab. Slabs having supports on less than four sides can be designed as oneway. Design project calculation sheet checked by pu date 080800 check the adequacy of the continuous composite profiled deck slab with spans of 3.
In the design of reinforcedconcrete buildings, solid and lightweight hollow block slabs are. Design of reinforced concrete structures ii twoway slabs. Investigating the effect of solid and lightweight hollow block slabs on. Flat slab analysis, design and detailing pdf civil engineering. Chapter 3 design of rectangular beams and oneway slabs. Analysis and design of slabs two way civil engineers pk. Flat slabs may have drop panels at columns and columns may have capitals. These blocks generally rest over on a reinforced concrete tbeam for support. 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 blocks are considered as nonstructural element as they do not contribute to strength of. A 120mmthick slab with a minimum rib thickness of 125 mm for continuous ribs is required to achieve a 2hour fire rating. These materials are originally located at different websites. The spanning oneway slab includes oneway spanning solid slab and oneway spanning hourdi block slab. Mar 02, 2016 design of solid slabs part 1 solid slab 15 ts.
The ratio of the total costs was found to be within the range 1. Oneway simply supported slab analysis and design of the slab similar to design of simply supported beam as indicate in the previous chapter. Sandwich slabs may have the disadvantage of a larger weight compared to the ribbed ones but on the other hand, they have the advantage that their spans and supports behave in the same proper way. The slab is propped at the centre during construction stage. The cross section of the profiled sheeting is shown in fig. Slabs are constructed to provide flat surfaces, usually horizontal in building floors, roofs, bridges, and other types of structures. The finite element method is commonly used to design the reinforcement in concrete slabs. After this publication, it was subsequently adopted by the uniform building. The slab may be supported by walls or by reinforced concrete beams usually cast monolithically with the slab or by structural steel beams or by columns, or by the ground. Accordingly, main reinforcement is required in the two directions. In case of ribbed slab the blocks are not permanent.
Introduction hollow block and ribbed slabs are formed by placing blocks on the slab and concrete ribs. Analyses are for a onebaywide strip using the equivalent frame analysis method of the aci code. The first step is to make a couple of design assumptions regarding the thickness of the slab and the clear spacing between ribs. Its not like a flat slab which is here and there i. Here, we have tried to gather various reading materials available in the web about flat slab floor system in one place. The works shall be performed as mentioned in this procedure and the quality assurance requirements shall be consistent with the relevant sections of quality system procedure manual of name of the contracting company as well with the project quality plan. It is also available in different measures, sizes and lengths, reaching up to length of 4m. Hourdi blocks hourdi block in uae hourdi block in dubai. Following are the rcc slab design and detailing guidelines. Flat slab system is an important division of concrete floor system. Design of reinforced concrete structures ii twoway slabs 1 1. Sandwich slab reinforcement details in reality, sandwich slabs are ribbed slabs with a slab placed both to their upper and lower surface.
If slab is supported on all four sides and r shorter side longer side slab. This thesis is a part of a project carried out at lulea university of technology. The concrete centre provides material, design and construction guidance. Structural steel composite slab 1 of 7 rev design project. Flat slab analysis, design and detailing pdf civil. Jul 02, 20 introduction hollow block and ribbed slabs are formed by placing blocks on the slab and concrete ribs. The cost is managed by supervision of non skilled laborers, following the recommendations in this manual. In both of them, the shear resistance has to be determined by means of slab tests, however the total number of test can be considerably reduced, because once the longitudinal strength. Design of rectangular beams and oneway slabs continued.
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