CEO s Note. Finally, I hope that this technical handbook will benefit all parties both in academic and industry. LOUIS HII The CEO of YKMW Groups

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2 CEO s Note First of all, I would like to congratulate and express my deepest appreciation to the team on their hard work and contribution to this handbook. Yung Kong Metal Works Co Bhd. (YKMW) has been in the steel wire production business since It started as a small factory along Abell Road, Kuching, Sarawak. Today, as one of the leading steel fabric manufacturers with its production plants located in Pending Industrial Estate, the company is equipped with automated welding machines with distinctive welding features. YKMW had received its ISO 9002: 1994 award certification in Further improvements in its management system, it was also awarded the ISO 9001: 0 Certification in 1 and ISO 9001: 2015 in It has also been recognized by Malaysia certification body, SIRIM QAS Sdn. Bhd. (SIRIM) for its welded steel fabric certified to MS 145: 1 in 5. The company has succeeded to upgrade this certification to MS 145: 6 in 9 and furthermore MS 145: 2014 in YMC Mesh Sdn. Bhd. has been one of the subsidiaries of YKMW Group since 8. It supplies custommade YMC welded steel fabric (YMC). It also provides fabric designed drawing and technical presentation as value-added services to customers. YMC is one of the latest solutions for our construction industry. It is certified by SIRIM to MS 145: 2014 Steel Fabric for the Reinforcement of Concrete Specification (Fourth Revision) and is recognized by Construction Industry Development Board (CIDB) Malaysia as a quality product for construction. This product and its manufacturing processes would be audited and tested by SIRIM yearly to ensure its compliance throughout the certification. YMC is fabricated from a series of high-strength cold reduced steel wires arranged at right angles to each other and electrically resistance welded at all intersections in square or rectangular grids. This automated welding process employs the fusion of pressure and heat, which combines the intersecting wires into a homogenous section without losing the strength or area. The welded intersections of YMC provide basic anchorage and further higher level of bonding is obtained by the positive rib profile on the wire. This will control and limit any development of crack line due to its close and consistent spacing of smaller wires. This YMC technical handbook is mainly served for the purposes of 1) providing the latest industrial standard and information as reference for design engineers; 2) providing the information as reference for the construction engineers in application; and 3) as a reference material for our local college students especially from the school of structural and civil engineering. Finally, I hope that this technical handbook will benefit all parties both in academic and industry. LOUIS HII The CEO of YKMW Groups 1

3 CONTENTS CEO s Note... 1 LIST OF TABLES... 5 LIST OF FIGURES... 6 LIST OF SYMBOLS... 7 CHAPTER 1: SPECIFICATION AND PRODUCT PROPERTIES 1.1 Specification MS 146: Scope Chemical Composition Quality of Finished Steel Tensile Properties Fatigue Strength Rebend Test Dimensions, Mass per Meter and Tolerances Surface Geometry MS 145: Scope Fabric Reference Chemical Composition Condition of Testing Tensile Properties Shear Force of Welded Joints Bend Performance Dimensions and Tolerance Packing and Marking

4 CHAPTER 2: DESIGN CONVERSION 2.1 Substitution of Steel Reinforcement Conversion Formula CHAPTER 3: DETAILING OF REINFORCEMENT 3.1 Concrete Cover Spacing of Reinforcement Bend Anchorage Ultimate Bond Stress Basic Anchorage Length Design Anchorage Length Example of Anchorage Calculation Lapping Laps Laps for Welded Steel Fabrics Made of Ribbed Bars Laps of the main reinforcement Laps of secondary or distribution reinforcement Type of Laps Overhang CHAPTER 4: DETAILING OF MEMBERS AND PARTICULAR RULES 4.1 Solid Slab One-Way Spanning Slab Two-Way Spanning Slab Minimum Area of Reinforcement, As min Minimum area for principal reinforcement Minimum area for secondary reinforcement Maximum Area of Reinforcement, As max Spacing for Reinforcement Minimum spacing for reinforcement Maximum spacing for reinforcement Reinforcement at Free Edge Simplified Detailing Rules for Slab Shear Reinforcement

5 4.2 Flat Slab Slab at Internal Columns Slab at Edge and Corner Columns Punching Shear Reinforcement Reinforced Concrete Wall Load Bearing Wall (Shear Wall) Non-Load Bearing Wall Vertical Reinforcement Maximum area of reinforcement Minimum area of reinforcement Horizontal Reinforcement Minimum area of reinforcement Transverse Reinforcement Retaining Wall Vertical Reinforcement Horizontal Reinforcement Reinforcement for Pad Footing Fabric up to Depth of Footing Hook Fabric Reinforcement for Drainage and Box Culvert REFERENCE ANNEX

6 LIST OF TABLES Table 1.1 : Industrial standards Table 1.2 : Chemical composition in percentage Table 1.3 : Characteristic tensile properties Table 1.4 : Fatigue test condition Table 1.5 : Mandrel diameter for rebend test Table 1.6 : Nominal cross-sectional area and mass per meter Table 1.7 : Tolerance on mass per meter Table 1.8 : Ranges for the rib parameters Table 1.9 : Characteristic relative rib area Table 1.10 : Fabric reference Table 2.1 : Substitution of fabric for high yield bars (f y,bar = 500 MPa) Table 3.1 (a) Minimum mandrel diameter to avoid damage of reinforcement for bar Table 3.1 (b) Minimum mandrel diameter to avoid damage of reinforcement for welded bent reinforcement and mesh bend after welding Table 3.2 : Values of α 1, α 2, α 3, α 4, α 5, coefficients Table 3.3 : Required lap lengths for secondary wires of fabric Table 4.1 : Minimum percentage of reinforcement 5

7 LIST OF FIGURES Figure 1.1 : Rib geometry Figure 1.2 : Fabric notation Figure 1.3 : Product label of YMC Figure 3.1 : Typical bends Figure 3.2 : Method of anchorage Figure 3.3 : Description of bond conditions Figure 3.4 : Values of K for beams and slabs Figure 3.5 : Adjacent laps Figure 3.6 : Lapping of welded fabric Figure 3.7 : Overhang Figure 4.1 : One-way spanning slab diagram Figure 4.2 : Load distribution for one-way spanning slab Figure 4.3 : One-way spanning slab fabric design layout (Bottom fabric) Figure 4.4 : One-way spanning slab fabric design layout (Top fabric) Figure 4.5 : Two-way spanning slab diagram Figure 4.6 : Load distribution for two-way spanning slab Figure 4.7 : Two-way spanning slab fabric design layout (Bottom fabric) Figure 4.8 : Two-way spanning slab fabric design layout (Top fabric) Figure 4.9 : Edge reinforcement for a slab Figure 4.10 : Simplified detailing rules for slab Figure 4.11 : Rules for curtailment of reinforcement of slab Figure 4.12 : Types of flat slab Figure 4.13 : Flat slab fabric design layout (Bottom fabric) Figure 4.14 : Flat slab fabric design layout (Top fabric) Figure 4.15 : Division of panels in flat slab Figure 4.16 : Effective width, b e, of a flat slab Figure 4.17 : Punching shear layout Figure 4.18 : Reinforced concrete wall cut section Figure 4.19 : Reinforced concrete wall fabric design layout Figure 4.20 : Reinforced concrete retaining wall fabric Figure 4.21 : Fabric up to depth of footing Figure 4.22 : Hook fabric for footing Figure 4.23 : U-Bend fabric Figure 4.24 : L-Bend fabric Figure 4.25 : Closed drain Figure 4.26 : Box culvert 6

8 LIST OF SYMBOL Symbol Description Unit Chapter 1 R e Yield strength MPa R m Tensile strength MPa A gt Percentage total elongation at maximum force % Ø Nominal diameter of the reinforcement steel mm h Rib height mm c Transverse rib spacing mm β Angle of transverse rib inclination degrees α Transverse rib flank inclination degrees A n Nominal cross-sectional area mm 2 Chapter 2 A s,fabric Equivalent area of steel fabric mm 2 /m A s,bar Area of steel bar mm 2 /m f y,bar Yield strength of steel bar MPa f y,fabric Yield strength of fabric MPa r Radius of steel bar mm Chapter 3 d g Maximum size of aggregate mm Ø m,min Minimum mandrel diameter mm Ø Diameter mm d Distance mm f bd Ultimate bond stress N/mm 2 l b Basic anchorage length mm l b,rqd Basic required anchorage length mm l b,min Minimum anchorage length mm l bd Design length mm p Transverse pressure MPa l 0 Lap length mm A s,prov Area of steel fabric provided mm 2 /m s Spacing of wires mm 7

9 Symbol Description Unit Chapter 4 l y Longer span mm l x Shorter span mm A s,min Minimum area of reinforcement mm 2 /m A sw,min Minimum area of a link leg for vertical punching shear reinforcement mm 2 /m A s,max Maximum area of reinforcement mm 2 /m A s,vmin Minimum area of vertical reinforcement mm 2 /m A s,vmax Maximum area of vertical reinforcement mm 2 /m A s,hmin Minimum area of horizontal reinforcement mm 2 /m A c Gross area of concrete section mm 2 A t Top reinforcement area mm 2 f ctm Mean tensile strength MPa f yk Characteristic yield strength of reinforcement MPa f ck Characteristic cylinder strength MPa b t/b e Effective width mm d Effective depth mm h Depth of slab mm L Effective length m y Distance from the edge of the slab to the innermost face of the column s max Maximum spacing mm α Inclination of the shear reinforcement V Ed Shear force kn V Rd,max Design value of the maximum shear force which can be sustained by the member, limited by crushing of the compression struts s r Spacing of shear links in the radial direction mm s t Spacing of shear links in the tangential direction mm mm kn 8

10 Chapter 1 SPECIFICATION AND PRODUCT PROPERTIES Malaysia steel mills produce and supply several kinds of steel products for construction industry such as hot rolled bar and wire rod. Low carbon wire rod complying with MS is widely used by downstream factories in producing cold drawn bar and welded steel fabric. The usage of welded steel fabric in construction industry is strictly controlled by Malaysian Government on its quality. Malaysian Standard MS 145: 2014 is the industrial standard to specify the properties and quality of welded steel fabric as the reinforcement of concrete. Furthermore, MS 146: 2014 controls the raw material used to fabricate this welded steel fabric complying with MS 145: The enforcement unit CIDB ensures only the certified products being used at construction sites. This chapter is mainly describing on the specifications and requirements of these Malaysian Standards, and the supporting notes to describe the properties of YMC (brand of YKMW) as a certified welded steel fabric. 9

11 1.1 SPECIFICATION Department of Standard Malaysia publishes specifications for steel bar and welded steel fabric. And the Standard and Industrial Research Institute of Malaysia (SIRIM) will audit and issue product certificates for the compliances. The appropriate Malaysian Standards are given in Table 1.1. Standard MS 146: 2014 MS 145: 2014 Table 1.1: Industrial standards Title Steel for The Reinforcement of Concrete Welded Reinforcing Steel Bar, Coil and Decoiled Product Specification (Fourth Revision) Steel Fabric for The Reinforcement of Concrete Specification (Fourth Revision) Note 1.1 YMC is certified to MS 145: 2014 with license number PY Yearly renewal of license is required and approval is subject to the result of audit and laboratory test conducted by SIRIM. YMC is further recognized by CIDB as a quality product with registration number SR0015. Note 1.2 Bar used for the fabrication of YMC is strictly complying with MS 146: MS 146: Scope This Malaysian Standard specifies requirements for ribbed weldable reinforcing steel used for the reinforcement of concrete structures. It contains provisions for three steel grades, all of 500 MPa characteristic yield strength, but with different ductility characteristics. The three grades are B500A, B500B and B500C. Note 1.3 Note 1.4 Bar quality of YMC is defined as cold worked ribbed bar grade B500A. Rib pattern of bar with grade B500A is described in MS 146: 2014 as the following. Bars shall have two or more series of parallel transverse ribs with the same angle of inclination and the same direction for each series. Example of rib pattern of grade B500A Note 1.5 Annex 2: The difference between the reinforcing bars B500A, B500B and B500C. 10

12 1.2.2 Chemical Composition The values of individual elements and the carbon equivalent shall not exceed the limits given in Table 1.2. Cast analysis Product analysis Table 1.2: Chemical composition in percentage Carbon max. Sulphur max. Phosphorus max. Nitrogen max. Copper max. Carbon equivalent max Quality of Finished Steel All bars shall be free from harmful defects which can be shown to adversely affect the mechanical properties of the steel. Rust, seams, surface irregularities or mill scale shall not be the cause of rejection provided the mass, dimensions, cross-sectional area and the mechanical properties of a hand wire brushed test specimen are not less than the requirements of this standard. Therefore, any surface rust which remains on the fabric is not harmful but in fact will increase the bond and anchorage properties of fabric. Loose rust can be easily removed during handling and shaking of fabric Tensile Properties MS 146: 2014 states the minimum requirements for characteristic tensile properties of bar used for welded steel fabric as described in Table 1.3. Grade Table 1.3: Characteristic tensile properties Yield Strength R e (MPa) Tensile/ Yield Strength Ratio R m /R e Total Elongation at Maximum Force A gt (%) B500A B500B B500C , < Note 1.6 Note 1.7 Note 1.8 R m/r e characteristic is 1.02 for sizes below 8 mm. A gt characteristic is 1.0 % for sizes below 8 mm. The absolute maximum permissible value of yield strength is 650 MPa. 11

13 1.2.5 Fatigue Strength Reinforcing bars shall be subjected to fatigue testing. When submitting to axial force controlled fatigue testing, using a stress ratio (σ max /σ min ) of 0.2, and stress range as in Table 1.4, test samples shall survive five million stress cycles. Bar size, Ø (mm) Table 1.4: Fatigue test condition Stress range (MPa) < Ø < Ø < Ø > Rebend Test Bend the test piece through an angle of 90, around a mandrel with a diameter not exceeding those specified in Table 1.5, age the test piece (refer to Condition of Testing) and then bend back by minimum 20. After the test, the specimen shall show no sign of fracture or cracks visible to a person of normal or corrected vision. Table 1.5: Mandrel diameter for rebend test Bar size, Ø (mm) 16 Maximum mandrel diameter 4Ø > 16 7Ø Dimensions, Mass per Meter and Tolerances The preferred nominal diameters (unit in mm) are 8, 10, 12, 16, 20, 25, 32 and 40. If bar is used for the manufacture of welded fabric in accordance with MS 145: 2014, then preferred nominal diameter shall include 6, 7 and 9 mm. 12

14 Table 1.6: Nominal cross-sectional area and mass per meter Nominal diameter (mm) Bar size, Ø (mm) Cross sectional area (mm 2 ) Table 1.7: Tolerance on mass per meter Mass per meter (kg) Tolerance on mass per meter (%) Ø > 8 ± 4.5 Ø 8 ± 6.0 Note 1.9 The preferred millimeter nominal sizes of bar for YMC fabrication are 6, 7, 8, 9, and Surface Geometry Rib is the protrusion on the outside of the bar produced through cold rolled process. It benefits in enhancing the bond and anchorage characteristics of the bar, better consistent properties and ductility. It also helps to minimize the crack widths in concrete elements as the force is well distributed through bond effect of ribbed bar as compared to plain bar. The values for the spacing, height and rib inclination of transverse ribs shall be within the range given in Table 1.8. Rib height, h Table 1.8: Ranges for the rib parameters Rib spacing, c Rib inclination, β 0.03Ø 0.15Ø 0.4Ø 1.2Ø

15 Figure 1.1: Rib geometry The projection of the transverse ribs shall extend over at least 75 % of the circumference of the product, which shall be calculated from the nominal diameter. The transverse rib flank inclination α shall be greater than or equal to 45, and the transition from the rib to the core shall be radiused. Where longitudinal ribs are present, there height shall not exceed 0.10Ø, where Ø is the nominal diameter of the product. Table 1.9: Characteristic relative rib area Nominal bar size, Ø (mm) Relative rib area Ø < Ø Ø > Note 1.10 Bar of YMC is certified for its rib pattern and unique bar marking which can be found on the surface along the bar. Bar Mark Description \ Y \ M \ C \ Brand \ 8 \ Bar size \ 1 \ Local manufacturing \ x \ Start of bar mark \ 9 \ Country code \ 1 \ 5 \ Registration number of CIDB 14

16 1.3 MS 145: Scope This Malaysian Standard specifies requirements for sheets of factory-made machine welded steel fabric for the reinforcement of concrete, manufactured from ribbed bars conforming to MS 146: Fabric Reference The fabric reference has been reviewed from nominal size to steel area in MS 145: Square mesh Rectangular mesh Table 1.10: Fabric reference MS 145: 6 MS 145: 2014 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 B5 B6 B7 B8 B9 B10 B11 B12 B13 Structural mesh A63 A98 A142 A193 A252 A318 A393 A475 A565 A664 B196 B283 B385 B503 B636 B785 B950 B1131 B

17 Long mesh C5 C6 C7 C8 C9 C10 C11 C12 C13 Small square mesh D4 D5 D6 D7 D8 D9 D10 D11 D12 D13 C196 C283 C385 C503 C636 C785 C950 C1131 C1328 Wrapping mesh D126 D196 D283 D385 D503 D636 D785 D950 D1131 D1328 Note 1.11 The preferred fabrics of YMC are stated as below. Type Fabric Reference Pitch (mm) A Square mesh B Structural mesh longitudinal bars spacing transverse bars spacing D Wrapping mesh x Note 1.12 Custom-made YMC refers to the fabrics which are different in dimensions according to the designed structures. However, it complies with MS 145: 2014 in the aspects of size, pitch, cross-sectional area and mass. Element Longitudinal bar Transverse bar Fabric length Fabric width Overhang length Description Diameter from 6 to 10 mm Diameter from 6 to 10 mm Up to 6.0 m Up to 2.4 m From 75 mm to 2.0 m 16

18 1.3.3 Chemical Composition The chemical composition of bars shall conform to the requirements of MS 146: Refer to Table 1.2 Chemical composition in percentage Condition of Testing Test piece shall be in aged condition: heat the test piece to C, maintain at this temperature (± 10 C) for a period of not less than 60 minutes (maximum 75 minutes) and then cool in still air to room temperature Tensile Properties Refer to Table 1.3: Characteristic tensile properties. Note 1.13 YMC is certified to grade B500A. Therefore, it shall comply with the requirements stated below. YMC Yield Strength R e Tensile/Yield Strength Ratio Total Elongation at Maximum Force Shear Force of Welded Joints A gt (MPa) R m/r e (%) (kn) A142 A193 A252 A318 A B283 B385 B503 B636 B D503 D636 D Shear Force of Welded Joints MS 145: 2014 states that the shear force of welded joints in welded fabric shall not be less than Where R e A n 0.25 x R e x A n is the specific characteristic yield strength; and is the nominal cross-sectional area of the larger bar of the welded joint. 17

19 The number of broken welds shall not exceed 4 % of the total number of cross welded joints in the sheet, nor exceed half the number of cross welded joints along any one bar. Note 1.14 Note 1.13 describes the shear force of welded joints of YMC in minimum Bend Performance Refer to Rebend Test. The bend test shall be conducted on the thicker bar Dimensions and Tolerance The pitch of longitudinal bars and transverse bars shall not less than 50 mm. The permitted deviation of welded steel fabric are: (a) (b) (c) length and width: ± 25 mm or ± 0.5 % whichever is the greater; bar pitch: ± 10 mm or ± 5 % whichever is the greater; and overhangs: to be agreed at the time of enquiry and order. Note 1.15 Reference A142 A193 A252 A318 A393 B283 B385 B503 B636 B785 D503 D636 D785 Certified reference of YMC. Nominal Bar Size (mm) Nominal Pitch (mm) Steel Area (mm 2 /m) Longitudinal Transverse Longitudinal Transverse Longitudinal Transverse Square mesh Structural mesh Wrapping mesh Mass (kg/m 2 )

20 Figure 1.2: Fabric notation W O 1 P m L O 2 O 4 P c O 3 Key: L W O 1 and O 2 O 3 and O 4 P m P c Length of the longitudinal bar (which are not necessarily the longer bar) in the sheet Length of the transverse bar Overhangs of the longitudinal bar Side overhangs of the transverse bar Pitch of the longitudinal bar Pitch of the transverse bar 19

21 1.3.9 Packing and Marking The manufacturer shall ensure that each bundle of output is securely tied with not less than four binders, and shall attach to bundle a durable label with the following information: (a) standard number, MS 145: 2014; (b) (c) (d) (e) (f) the grade of fabric; the type of fabric; the name of fabric manufacturer; the dimension of fabric; and number of sheet. Figure 1.3: Product label of YMC 20

22 Chapter 2 DESIGN CONVERSION This chapter includes the substitution for steel reinforcement from conventional steel bar to welded steel fabric and shows the conversion formula. As we know, using welded steel fabric drastically speeds up the construction process. It is available in wide range of bar diameters each suited for a particular reinforcing design application. The conventional steel bar reinforcement can be substituted with welded steel fabric resulting in easier controls, increase speed of installation, reducing offcuts and wastage. 21

23 2.1 SUBSTITUTION OF STEEL REINFORCEMENT Welded steel fabric is the product used to reinforce concrete in construction. Fabric is made up of high tensile steel bars which are welded together using the modern technology. This welded steel fabric is used as a substitution for the conventional method of reinforcement using steel bars. YMC is one of the local brands of welded steel fabric which supplies custom-made fabric for local construction industries Conversion Formula Previously, according to MS 146: 6, the high yield tensile bar is 460 MPa. By referring to the latest version of MS 146: 2014 (Chapter 1, Table 1.3: Characteristic tensile properties), the new high yield tensile bar is 500 MPa. To determine equivalent fabric area, A s,fabric, the general conversion formula is defined below: Where A s,bar is the area of steel bar in mm 2 /m; f y,bar is the yield strength of steel bar in MPa; and f y,fabric is the yield strength of fabric in MPa. A s,fabric = A s,bar f y,bar f y,fabric Since the yield strength for high tensile bar and steel fabric are both 500 MPa, we can assume that: A s,fabric = A s,bar Note 2.1 Note 2.2 High yield bar, f y,bar = 500 MPa YMC welded steel fabric, f y Fabric = 500 MPa Table 2.1 shows the conversions of common bar diameter and spacing for easy reference purpose. Suitable fabric reference could be selected from fabric table based on converted equivalent fabric area. The area of recommended fabric reference should be equal or greater than the equivalent fabric area. 22

24 Table 2.1: Substitution of fabric for high yield bars (f y,bar = 500 MPa) Nominal Size Ø (mm) Bars Spacing (mm) Area of steel bar, A s,bar (mm 2 /m) Equivalent fabric area, A s,fabric (mm 2 /m) Fabric Recommended YMC Fabric Reference B503 (B8), D503 (D8) A393 (A10), B385 (B7) A252 (A8) A252 (A8) A193 (A7) B785 (B10), D785 (D10) B636 (B9), D636 (D9) A393 (A10) A318 (A9), B385 (B7) A318 (A9), B283 (B6) B785 (B10), D785 (D10) B636 (B9), D636 (D9) B503 (B8), D503 (D8) A393 (A10), B385 (B7) B785 (B10), D785 (D10) Note 2.3 Certified reference for YMC is shown in Chapter 1, Note To determine the area of steel bar, A s,bar as stated in Table 2.1, the formula below is given: Where π r Step 1: Area of steel bar, A s,bar = πr 2 Step 2: No.of bar per m = Step 3: is 3.142; and radius of steel bar. Area of steel bar per m = A s,bar no.of bar per m Work example below shows the substitution from steel bar to welded steel fabric. Parameter Bar diameter 8 mm Bar spacing 150 mm 1 metre run 0 mm π f y,bar 500 MPa f y,fabric 500 MPa 0 (bar spacing) 23

25 Calculation Area of steel bar = πr 2 8 = ( ) 2 = mm 2 2 No. of bar per metre = 1 m 0 = = no.of bar/m bar spacing 150 Area of steel bar per m Area of steel bar = no.of bar per m = = ~ 335 mm 2 /m f y,bar f y,fabric 500 Equivalent area of fabric = A s,bar = 335 = 335 mm 2 /m 500 Hence, the recommended YMC Fabric is A393 (A10) or B385 (B7). 24

26 Chapter 3 DETAILING OF REINFORCEMENT This chapter will explain the detailing for the reinforcement. Reinforcement is important to resist internal tensile forces calculated from analysis. Also, reinforcement is provided in compression zones to increase the compression capacity, enhance ductility, reduce long term deflections, or increase the flexural capacity for beams. In addition, reinforcement is required to prevent excessive cracking resulting from shrinkage or temperature changes in restrained structural elements. It is important to provide the adequate area of reinforcement required to resist internal tensile or compression forces required to attain the design strength. The provided area of reinforcement is not fully effective unless it is fully developed, it may be developed by bending, anchorage, lapping and etc. In addition to provide the sufficient areas of reinforcement, good detailing should be done considering the overall structural integrity. 25

27 3.1 CONCRETE COVER As stated in Clause , MS EN : 2010, the concrete cover is the distance between the surface of the reinforcement closest to the nearest concrete surface (including links and stirrups and surface reinforcement where relevant) and the nearest concrete surface. The nominal cover shall be specified on the drawings. 3.2 SPACING OF REINFORCEMENT The spacing of bars shall be such that the concrete can be placed and compacted satisfactorily for the development of adequate bond. The clear distance (horizontal and vertical) between individual parallel bars or horizontal layers of parallel bars should be not less than the maximum of k 1 x bar diameter, (d g + k 2 mm) or 20 mm where d g is the maximum size of aggregate. Where bars are positioned in separate horizontal layers, the bars in each layer should be located vertically above each other. There should be sufficient space between the resulting columns of bars to allow access for vibrators and good compaction of the concrete. Lapped bars may be allowed to touch one another within the lap length. Note 3.1 Clause 8.2, MS EN : Note 3.2 The recommended value of k 1 and k 2 are 1 and 5 mm respectively. 3.3 BEND The minimum diameter to which a bar is bent shall be such as to avoid bending cracks in the bar, and to avoid failure of the concrete inside the bend of the bar. In order to avoid damage to the reinforcement the diameter to which the bar is bent (mandrel diameter) should not be less than Ø m,min (Refer Table 3.1). Note 3.3 Clause 8.3 MS EN : Table 3.1 (a): Minimum mandrel diameter to avoid damage of reinforcement for bar Bar size, Ø (mm) 16 Minimum mandrel diameter for bends, hooks and loops 4Ø > 16 7Ø Note 3.4 Adapted from Table 8.1N MS EN :

28 Table 3.1 (b): Minimum mandrel diameter to avoid damage of reinforcement for welded bent reinforcement and mesh bend after welding Minimum mandrel diameter or d or 5Ø For d 3Ø, use 5Ø For d < 3Ø or welding between the curved zone, use 20Ø Note 3.5 The mandrel size for welding within the curved zone may be reduced to 5Ø where the welding is carried out in accordance with MS EN ISO Annex B. Figure 3.1: Typical bends Longitudinal bar Transverse bar Single Bend Double Bend 27

29 3.4 ANCHORAGE Reinforcing bars or welded steel fabrics should be anchored so that the bond forces are safely transmitted to the concrete avoiding longitudinal cracking or spalling. Transverse reinforcement shall be provided if necessary. Method of anchorage are shown in Figure 3.2. Note 3.6 Clause 8.4.1, MS EN : Figure 3.2: Method of anchorage Ultimate Bond Stress The ultimate bond strength shall be sufficient to prevent bond failure. The design value of the ultimate bond stress, f bd for ribbed bars as shown below: Where f ctd η 1 f bd = 2.25η 1 η 2 f ctd is the design value of concrete tensile strength according to (2)P. Due to the increasing brittleness of high strength concrete, f ctk,0.05 should be limited here to the value for C60/75, unless it can be verified that the average bond strength increases above this limit. is the coefficient related to the quality of the bond condition and the position of the bar during concreting, η 1 =1.0 when good conditions are obtained. η 1 = 0.7 for all other cases and for bars in structural elements built with slipforms, unless it can be shown that good bond conditions exist. 28

30 η 2 is related to the bar diameter η 2 = 1.0 for Ø 32 mm η 2 = (132 Ø)/ for Ø > 32 mm Figure 3.3: Description of bond conditions Direction of concreting a) and b) good bond conditions for all bars c) and d) unshaded area: good bond conditions shaded area: deficient bond conditions Note 3.7 Clause 8.4.2, MS EN : Basic Anchorage Length The basic required anchorage length, l b,rqd, for anchoring the force A s. σ sd in a straight bar assuming constant bond stress equal to f bd follows from: l b,rqd = (Ø/4)(σ sd /f bd ) Where σ sd is the design stress of the bar at the position from where the anchorage is measured from. Where pairs of wires/bars form welded fabrics the diameters, Ø should be replaced by the equivalent diameter Ø n = Ø 2. Note 3.8 Clause 8.4.3, MS EN :

31 3.4.3 Design Anchorage Length The design anchorage length, l bd is: l bd = α 1 α 2 α 3 α 4 α 5 l b,rqd l b,min Where α 1,α 2,α 3,α 4,α 5 are coefficients given in Table 3.2 α 1 α 2 is for the effect of the form of the bars assuming adequate cover is for the effect of concrete minimum cover C 1 C a C 1 a C a) Straight bars c d = min (a/2, c 1, c) b) Bent or hooked bars c d = min (a/2, c 1 ) c) Looped bars c d = c α 3 α 4 α 5 is for the effect of confinement by transverse reinforcement is for the influence of one or more welded transverse bars (Ø ǀ > 0.6Ø) along the design anchorage length, l bd is for the effect of the pressure transverse to the plane of splitting along the design anchorage length The product (α 2 α 3 α 5 ) 0.7 l b,min is the minimum anchorage length if no other limitation is applied: - For anchorages in tension: l b,min > max {0.3l b,rqd ;10Ø; mm} - For anchorages in compression: l b,min > max {0.6l b,rqd ;10Ø; mm} The tension anchorage of certain shape in Figure 3.2 may be provided as an equivalent anchorage length, l b,eq. l b,eq is defined : - α 1 l b,rqd for shapes shown in Figure 3.2b to 3.2d - α 4 l b,rqd for shapes in Figure 3.2e Note 3.9 Clause 8.4.4, MS EN :

32 Influencing factor Shape of bars Concrete cover Confinement by transverse reinforcement not welded to main reinforcement Confinement by welded transverse reinforcement Confinement by transverse pressure Table 3.2: Values of α 1, α 2, α 3, α 4, α 5 coefficients Type of anchorage Reinforcement bar In tension In compression Straight α 1 = 1.0 α 1 = 1.0 Other than straight Straight Other than straight All types α 1 = 0.7 if c d > 3Ø otherwise α 1 = 1.0 α 1 = (c d - Ø)/Ø α 1 = (c d - 3Ø)/Ø α 3 = 1 - Kλ α 1 = 1.0 α 2 = 1.0 α 2 = 1.0 α 3 = 1.0 All types α 4 = 0.7 α 4 = 0.7 All types α 5 = p Note 3.10 Adapted from Table 8.2 MS EN : Where λ ΣA st ΣA st,min A s K p (ΣA st - ΣA st,min )/A s cross-sectional area of the transverse reinforcement along the design anchorage length, l bd cross-sectional area of the minimum transverse reinforcement = 0.25 A s for beams and 0 for slabs area of a single anchored bar with maximum bar diameter values shown in Figure transverse pressure (MPa) at ultimate limit state along l bd Figure 3.4: Values of K for beams and slabs A s Ø t, A st A s Ø t, A st A s Ø t, A st K = 0,1 K = 0,05 K = 0 31

33 3.4.4 Example of Anchorage Calculation Parameter: Concrete cover = 25 mm f y = 500 N/mm 2 f ck,cube =30 N/mm 2 Ø = 7 mm A s = 193 mm 2 (A193) No. of bar = 5 Assume bot area of rebar near support is 50% As 0.5A s = = mm 2 F b = 0.87f y A s = 0.87 x 500 x = kn From Table 3.1 (MS EN : 2010), f ck,cube = 30 N/mm 2, f ctd = 1.8 η 1 = 0.7 η 2 = 1.0 Design value of the ultimate bond stress f bd = 2.25η 1 η 2 f ctd = 2.25(0.7)(1.0)(1.8) = N/mm 2 Design stress of bars F b σ sd = = 3 = N/mm 2 no. of bar πr 2 5 π Basic required anchorage length ( ) σ sd ( ) ( 4 )( ) l b,rqd = = = mm 4 f bd

34 Tension α 1 = (c d (25 - (5 7)) α 2 = 1 - = 1 - = x 7 ( ) a - 14 c d = min = = 25 mm 2,c 1,c,25,25 2 α 3 = 1 - Kλ = 1-0 = 1 α 4 = 1 α 5 = 1 ( ) { 5 } { } l b,min = max 0.3 l b,rqd,10, mm = max ,10(7), mm = mm/bar 5 Design anchorage length l bd = α 1 α 2 α 3 α 4 α 5 l b,rqd l b,min = (1)(1.043)(1)(1)(1)(673.27) = mm (for 5 no.of bar) Hence, 1 bar length = = mm l b,min = mm 3.5 LAPPING Laps The detailing of laps between bars shall be such that: (a) (b) (c) the transmission of the forces from one bar to the next is assured; spalling of the concrete in the neighbourhood of the joints does not occur; and large cracks which affect the performance of the structure does not occur. Laps between bar should normally be staggered and not located in areas of high moments/forces. The arrangement of lapped bars should comply with Figure 3.4, as set out below: (a) the clear distance between lapped bar should not be greater than 4Ø or 50 mm, otherwise the lap length should be increased by a length equal to the clear space where it exceeds 4Ø or 50 mm; (b) the longitudinal distance between two adjacent laps should not be less than 0.3 times the lap length, l 0 ; and (c) in case of adjacent laps, the clear distance between adjacent bars should not be less than 2Ø or 20 mm. 33

35 When the provisions comply with the statement above, the permissible percentage of lapped bars in tension may be % where the bars are all in one layer. Where the bars are in several layers, the percentage should be reduced to 50 %. All bars in compression and secondary (distribution) reinforcement may be lapped in the same location. Note 3.11 Clause 8.7.2, MS EN : Figure 3.5: Adjacent laps F s 0,3l 0 l 0 50 mm 4Ø Ø F s F s a 2Ø 20 mm F s F s F s Laps for Welded Steel Fabrics Made of Ribbed Bars Laps of the main reinforcement Laps may be made either by intermeshing or by layering fabrics. For intermeshed fabric, the lapping arrangements for the main longitudinal bars should conform to Clause For layered fabric, the laps of the main reinforcement should be generally be situated in zones where the calculated stress in the reinforcement at ultimate limit state is not more than 80 % of the design strength. The permissible percentage of the main reinforcement that may be spliced by lapping in any section, depends on the specific cross-section area of the welded fabric provided (A s /s) prov, where s is the spacing of wires: (a) % if (A s /s) prov 1 mm 2 /m (b) 60 % if (A s /s) prov > 1 mm 2 /m Note 3.12 Clause , MS EN :

36 Figure 3.6: Lapping of welded fabric F s F s a) intermeshed fabric (longitudinal section) l 0 F s F s b) layered fabric (longitudinal section) l Laps of secondary or distribution reinforcement All secondary reinforcement may be lapped at the same location. The minimum values of the lap length, l 0 are shown in the Table 3.3 below. Table 3.3: Required lap lengths for secondary wires of fabric Diameter of secondary bar, Ø (mm) Ø 6 Lap lengths 150 mm; at least 1 wire pitch within the lap length 6 < Ø mm; at least 2 wire pitches 8.5 < Ø mm; at least 2 wire pitches Note 3.13 Clause , MS EN :

37 3.5.3 Type of Laps Full yield strength lap - The most common type lapping used. - Transfer the full yield strength of the reinforcement. - Staggered arrangement is to avoid accumulation of laps. Half yield strength - Half yield strength laps with overlap of only one cross weld are acceptable in side laps of one-way slab. This is commonly used in top (negative) reinforcement. - Transfer half the yield strength of the reinforcement - May be use for side laps across beams Reversed or nested-in-plane lap - Particularly useful in situations of maximum stress to maintain the lapped reinforcement in the same plane Flying ends lap - Alternative method in plane lapping where one sheet is provided with a lap length overhang without welded intersections - The lap length is determined as for lapped bars (plain or deformed wires), and without welded intersection on lapped wires, the ultimate anchorage bond stress of fabric do not apply Non-yield strength transfer splice lap - May be used for secondary direction lapping over beam or secondary direction lapping where splice transfer is not important 36

38 3.6 OVERHANG Overhang refers to the distance between the tip of the wire and the first weld joint. Other than the overall dimensions and spacings of the wires that determine the overhang to be provided, the usage of the fabric also plays and important role in deciding the suitable length of overhang. Figure 3.7: Overhang Specified length of overhangs 37

39 Chapter 4 DETAILING OF MEMBERS AND PARTICULAR RULES The detailing of members and particular rules is very important with regard to the safety, serviceability and durability. It should be consistent with the design models adopted. Therefore, the minimum areas of reinforcement are given in order to prevent brittle failure, wide cracks and to resist forces arising from restrained actions. This chapter includes the detailing of members and particular rules for solid slab, flat slab, wall and retaining wall. The application of welded steel fabric in pad footing and drainage also shown in this chapter. 38

40 4.1 SOLID SLAB One-Way Spanning Slab One-way spanning slab is a slab which is supported by beams on the two opposite sides to carry the load along one direction. In one-way spanning slab, the ratio of longer span (l y ) to shorter span (l x ) is equal or greater than 2, i.e. longer span (l y ) / shorter span (l x ) 2. Figure 4.1: One-way spanning slab diagram Figure 4.2: Load distribution for one-way spanning slab A B l x C D l y 39

41 Figure 4.3: One-way spanning slab fabric design layout (Bottom fabric) Bottom fabric 40

42 Figure 4.4: One-way spanning slab fabric design layout (Top fabric) Top fabric 41

43 4.1.2 Two-Way Spanning Slab When a reinforced concrete slab is supported by beams on all the four sides and the loads are carried by the supports along both directions, it is known as two-way spanning slab. In two-way spanning slab, the ratio of longer span (l y ) to shorter span (l x ) is less than 2, i.e. longer span (l y ) / Shorter span (l x ) < 2. Figure 4.5 Two-way spanning slab diagram Figure 4.6: Load distribution for two-way spanning slab A B E F l x C l y D 42

44 Figure 4.7: Two-way spanning slab fabric design layout (Bottom fabric) Bottom fabric 43

45 Figure 4.8: Two-way spanning slab fabric design layout (Top fabric) Top Fabric Minimum Area of Reinforcement, A s,min Minimum area for principal reinforcement The minimum area of principal reinforcement in the main direction is shown below: A s,min = 0.26f ctmb t d f yk Where f ctm f yk b t mean tensile strength; characteristic yield strength of reinforcement; and effective width; and d = effective depth 44

46 Table 4.1: Minimum percentage of reinforcement f ck f ctm Minimum percentage (0.26 f ctm /f yk2 ) Note 4.1 Adapted from Table 3.1, MS EN : Note 4.2 Assume f yk = 500 MPa Minimum area for secondary reinforcement Secondary transverse reinforcement of not less than 20 % A s,min should be provided in one way slabs. In area of near supports, transverse reinforcement is not necessary where there is no transverse bending moment Maximum Area of Reinforcement, A s,max Outside lap locations, the maximum area of tension or compression reinforcement should not exceed A s,max = 0.04 A c Spacing for Reinforcement Minimum spacing for reinforcement The minimum clear distance between bars should be greater than: (a) bar diameter; (b) aggregate size plus 5 mm; and (c) 20 mm Maximum spacing for reinforcement For slab which is less than mm thick, the following maximum spacing, s max,slabs rules are apply. (a) (b) For the principal reinforcement: 3h but not more than 400 mm. For the secondary reinforcement: 3.5h but not more than 450 mm. 45

47 The exception is in areas with concentrated loads or areas of maximum moment where the following applies. (a) (b) For the principal reinforcement: 2h but not more than 250 mm. For the secondary reinforcement: 3h but not more than 400 mm. Where h = the depth of the slab Note 4.3 Clause , MS EN : Reinforcement at Free Edge Along a free (unsupported) edge, a slab should normally contain longitudinal and transverse reinforcement, generally arranged as shown in Figure 4.9. The normal reinforcement provided for a slab may act as edge reinforcement. Figure 4.9: Edge reinforcement for a slab h 2h Note 4.4 Clause , MS EN : Simplified Detailing Rules for Slab The detailing rules are used for slabs in the following circumstances: (a) (b) The slabs are designed for predominantly uniform distributed loads. In the case of continuous slab, design has been carried out for the single load case of maximum design load on all spans and the spans are approximately equal. 46

48 Figure 4.10: Simplified detailing rules for slab Face of support % 0.15l l bd Reinforcement for maximum hogging moment 50% 0.30l a) Continuous member, top reinforcement 40% Position of effective support 0.2l % Reinforcement for maximum sagging moment b) Continuous member, bottom reinforcement 15% l bd Face of support % c) Simple support, bottom reinforcement Figure 4.11: Rules for curtailment of reinforcement of slab 0.15L or 45ø 0.3L 0.3L 50% As % As 40% As 47

49 4.1.8 Shear Reinforcement A slab in which shear reinforcement is provided should have a depth at least mm. The shear reinforcement should form an angle, α of between 45 to 90 to the longitudinal axis of the structural element. In slab, if V Ed 1 3 V Rd,max', the shear reinforcement may consist entirely of bent-up-bars or of shear reinforcement assemblies. Where V Rd,max' V Ed is the design value of the maximum shear force which can be sustained by the member, limited by crushing of the compression struts; and is shear force The maximum longitudinal spacing of successive series of links is given by s max = 0.75d(1 + cot α) Where α d is inclination of the shear reinforcement; and is effective depth. The maximum longitudinal spacing of bent-up bars is given by s max = d The maximum transverse spacing of shear reinforcement should not exceed 1.5 d. Note 4.6 Clause 9.3.2, MS EN :

50 4.2 FLAT SLAB Flat slab is a reinforced concrete slab supported directly by concrete columns without the use of beams. Flat slab is defined as one sided or two-sided support system with sheer load of the slab being concentrated on the supporting column and a square slab called drop panel. Flat slab Figure 4.12: Types of flat slab Flat slab with column head Flat slab with drop panel 49

51 Figure 4.13: Flat slab fabric design layout (Bottom fabric) Bottom fabric 50

52 Figure 4.14: Flat slab fabric design layout (Top fabric) Top fabric 51

53 A flat slab should be divided into column and middle strips as shown in Figure Figure 4.15: Division of panels in flat slab l x > l y l y /4 l y /4 Middle strip = l x - l y /2 l y / 4 l y / 4 Middle strip = l y /2 l y Column strip = l y / Slab at Internal Columns At internal columns, unless rigorous serviceability calculations are carried out, top reinforcement of area 0.5 A t should be placed in a width equal to the sum of times the panel width on either side of the column. A t represents the area of reinforcement required to resist the full negative moment from the sum of the two half panels each side of the column. It is also advisable to apply this requirement to perimeter columns as far as is possible. At internal columns at least two bars of bottom reinforcement in each orthogonal direction should be provided and they should pass between the column reinforcement. Note 4.5 Clause 9.4.1, MS EN :

54 4.2.2 Slab at Edge and Corner Columns Reinforcement perpendicular to a free edge required to transmit bending moments from the slab to an edge or corner column should b e placed within the effective width, be, shown in Figure Figure 4.16: Effective width, b e, of a flat slab A c z A c z y c y y c y b e = c z + y z b e = z + y/2 A A Slab edge Note: y can be > c y b) Edge column Note: z can be > c z and y can be > c y b) Corner column Note 4.6 y is the distance from the edge of the slab to the innermost face of the column. Note 4.7 Clause 9.4.2, MS EN : Punching Shear Reinforcement Where punching shear reinforcement is required, it should be placed between the loaded area/column and kd inside the control perimeter at which shear reinforcement is no longer required. It should be provided in at least two perimeters of shear links. The radial spacing of the links of should not exceed 0.75d. The tangential spacing of the links should not exceed 1.5d within the 2d from the column face, and should not exceed 2d for any other perimeter. The distance between the face of the column and the nearest shear reinforcement should be less than 0.5d. Note 4.8 From Clause (4) MS EN : 2010, the recommended value of k is

55 Figure 4.17: Punching shear layout Section A - A The minimum area of a link leg for vertical punching shear reinforcement is: 1.5 A sw,min /(s r.s t ) 0.08 f ck /f yk Where s r s t is spacing of shear links in the radial direction; and is spacing of shear links in the tangential direction. Note 4.9 Clause 9.4.3, MS EN : REINFORCED CONCRETE WALL Load Bearing Wall (Shear Wall) Load bearing wall carries loads imposed on it from beams and slabs above including its own weight and transfer it to the foundation. These walls support structural members such as beams, slabs and walls on above floors above Non-Load Bearing Wall Non-load bearing walls only carry their own weight and does not support any structural members such as beams and slabs. These walls are just used as partition walls or to separate rooms from outside. 54

56 Figure 4.18: Reinforced concrete wall cut section mm THK. R.C. WALL TO DETAIL 2 LAYERS YMC A8 R.C. WALL TO DETAIL T10 C/C E.F. STARTER BARS 400 (LAP) GROUND BEAM TOP LEVEL 650 R.C. SLAB TO DETAIL R.C. STRIP FOOTING

57 Figure 4.19: Reinforced concrete wall fabric design layout Vertical Reinforcement Maximum area of reinforcement The maximum nominal reinforcement area, A s,vmax for columns and walls outside laps is 0.04A c. However, this area can be increased provided that the concrete can be placed and compacted sufficiently. 56

58 Minimum area of reinforcement The minimum area of vertical reinforcement in walls is given by: A s,vmin = 0.002A c. Half the area should be provided in each face. The distance between two adjacent vertical bars should not exceed the lesser of either three times the wall thickness or 400 mm. Note 4.10 Clause 9.6.2, MS EN : Horizontal Reinforcement Horizontal reinforcement running parallel to the faces of the wall (and to the free edges) should be at each surface. It should not be less than A s,hmin Minimum area of reinforcement The minimum area of horizontal reinforcement in walls is given by: A s,hmin = 0.001A c or 25 % whichever is greater. The spacing between two adjacent horizontal bars should not be greater than 400 mm. Note 4.11 Clause 9.6.3, MS EN : Transverse Reinforcement In any part of a wall where the total area of the vertical reinforcement in the two faces exceeds 0.02A c, transverse reinforcement in the form of links should be provided in accordance with the requirements for columns which is the diameter of the bars of welded steel fabric for transverse reinforcement should not be less than 5 mm. Where the main reinforcement is placed nearest to the wall faces, transverse reinforcement should also be provided in the form of links with at least of 4 per m 2 of wall area. Note 4.12 Transverse reinforcement need not to be provided where welded steel fabric and bars of diameter less than 16 mm are used with the concrete cover larger than 2Ø. Note 4.13 Clause 9.6.4, MS EN :

59 4.4 RETAINING WALL A retaining wall is a structure designed and constructed to retain earth or other material in vertical (or nearly vertical) position at locations where an abrupt change in ground level occurs. It is to prevent retained earth from assuming its natural angle of repose. The retained earth exerts lateral pressure on the wall by stability analysis overturn, slide and settlement. Therefore, the wall must be design to be stable under the effects of lateral pressure. Figure 4.20: Reinforced concrete retaining wall fabric Vertical Reinforcement Where axial forces dominate, the minimum area of vertical reinforcement is 0.002A c ; half this area should be placed in each face. Outside lap locations, the maximum area of vertical reinforcement is 0.04A c ; this may be doubled at lap locations. The distance between two adjacent vertical bars should not exceed the lesser of either three times the wall thickness or 400 mm. For walls with a high axial load, the main reinforcement placed nearest to the wall faces should have transverse reinforcement in the form of links with at least four per m 2 of wall area. Where welded fabric and bars of diameter less than 16 mm are used with cover larger than 2Ø, transverse reinforcement is not required. 58

60 4.4.2 Horizontal reinforcement The minimum area of horizontal reinforcement is greater of either 25 % of vertical reinforcement or 0.001A c. However, where crack control is important, early age thermal and shrinkage effects should be considered. Where flexural forces dominate, these requirements may be relaxed to 20 % of the vertical reinforcement area. 4.5 REINFORCEMENT FOR PAD FOOTING Foundations which carry and spread concentrated loads to the soil from superstructures is called pad footing. They are usually placed to transfer point loads from the column or framed structures and consists of a concrete block or concrete pad. The pads are usually placed at a shallow depth, but they can also be used as deep foundation depending on the loads to be transferred and condition of the subsoil. Pad footing may be square, rectangular or circular in shape. If the pad is subjected to a heavy loaded structure, the pad footing may be stepped. The loads from the structure are simply distributed by the pad to the bearing layer of soil. Below shows the footing using fabric reinforcement Fabric up to Depth of Footing In this type of fabric, the bars are bent at ends up to a height of footing. The concrete cover is provided in all the sides of the footing. Figure 4.21: Fabric up to depth of footing 59

61 4.5.2 Hook Fabric This type of fabric is adopted in low rise and also high-rise building. The footing is reinforced as grid and at the ends of the fabric, the bars are hooked. Bending the bars ends helps in the proper anchorage of reinforcement, where the hook length is 9Ø, Ø is the diameter of bar. Figure 4.22: Hook fabric for footing 4.6 REINFORCEMENT FOR DRAINAGE AND BOX CULVERT For drainage and box culvert, the cut to size fabric can be because it is easier to install and will minimize the installation time at the site. Below shows the figure of drainage and box culvert using cut to size fabric. Figure 4.23: U-Bend fabric U-Bend Fabric 60

62 Figure 4.24: L-Bend fabric Width varies L-Bend Fabric Depth varies Additional tie bars for hunching to engineer's requirement Figure 4.25: Closed drain 61

63 62 Figure 4.26: Box culvert

64 REFERENCES 1. MS 145: 2014, Steel Fabric for the Reinforcement of Concrete Specification (Fourth Revision) 2. MS 146: 2014, Steel for the Reinforcement of Concrete Weldable Reinforcing Steel Bar, Coil and Decoiled Product Specification (Fourth Revision) 3. MS EN : 2010, Malaysia National Annex to Eurocode 2: Design of Concrete Structures Part 1-1: General Rules and Rules for Buildings 4. The Concrete Centre, (6). How to Design Concrete Structure using Eurocode 2. Retrieved from concrete%20structures%20using%20eurocode%202.pdf 5. Krishna (2017). Types of Reinforcement or Mesh used in Different Footings (Foundations). Retrieved from 6. Farid, N.M. (2010). Reinforced Slab. Retrieved from 7. Ibrahim, I.S. (2017). Design of Retaining Walls. Retrieved from 63

65 ANNEX 1 PROCESS FLOW 1. SIRIM certified wire rod as raw material of welded steel fabric 2. Drawing process to reduce size and rib wire rod to required bar size. 3. Electronically controlled welding process combines the intersecting wires into a homogenous section 64

66 4. Bending machine to bend the welded steel fabric 5. Sample will be taken during welding process for laboratory test on its properties 6. Output with unique label from production will be stored inside warehouse under the roof 7. Delivery and unloading of welded steel fabric at site 65

67 8. Formwork installation at site 9. Installation of welded steel fabric at site 10. Concreting of slab at site 66

68 ANNEX 2 THE DIFFERENCE BETWEEN THE REINFORCING BARS B500A, B500B AND B500C Reinforcing Steel Type B500A B500B B500C Surface Smooth, dented, ribbed Dented, ribbed Ribbed Delivery form Rollers, bars, point welded reinforcement meshes, lattice girders Nominal diameter (mm) Min. yield / yield strength Re (Mpa) Rollers, bars, welded reinforcement meshes Re, act / Re, nom <1.25 Min. ratio Rm / Re 1.05a c; <1.35 Min. elongation at max. load Agt (%) Min. fatigue strength 2σad (MPa) Min. shear force - gepuntl.wap. Fs - lattice gripper Fw / d (kn) Tolerance nominal diameter (%) Chem. composition (mass%) Min. relative opp. cross-rib (dent), fr / pf 3.0a, b 5.0b 7.5b, c d 28 mm: 175 d > 28 mm: x An x Re 0.25 x Ao / bx Re, o / b or 0.6 x Ad x Re, d 0.25 x An x Re 0.25 x Ao / bx Re, o / b or 0.6 x Ad x Re, d ± 4.5 ± 4.5 ± 4.5 C < 0.22, etc Ceq < 0.50 a) Rm / Re1.03 and Agt 2.0 for diameters 5.5 mm b) Agt for rolls + 0.5% C < 0.22, etc Ceq < 0.50 d = : d = : d = : d = : c) Rm / Re min and Agt 7.0% for diameters 12 mm d 28 mm: 175 d > 28 mm: x An x Renvt C < 0.22, etc Ceq < 0.50 d) Maximum stress ripple 2σa at top tension 0.6Read (300 MPa) and 1 million voltage changes. For top welded reinforcement meshes B500B and B500C, 2σa is at least MPa. For roll-oriented products, 2σa minus MPa, unless a higher value ( 175 MPa) has been statistically demonstrated for the maximum diameter used and for the target machine (type). e) In the case of lattice girders, the lower rods must comply with B500A and / or B500B with the fr / P requirement. The top bars and diagonals may be reinforcing bars with only the requirements of Re, d and the chemical composition. f) For rolls fr (ribbed) + 15%, fp (dented) + 5%. No requirement for weakly profiled / dented reinforcing steel (lattice girders). Source: 67

69 68 ANNEX 3 PREFERRED RANGE OF DESIGNATED FABRIC TYPES GRADE B500A Reference Nominal Bar Size (mm) Nominal Pitch (mm) Steel Area (mm 2 /m) Mass (kg/m 2 ) Longitudinal Transverse Longitudinal Transverse Longitudinal Transverse Square mesh A63 A98 A142 A193 A252 A318 A393 A475 A565 A Structural mesh B196 B283 B385 B503 B636 B785 B950 B1131 B Long mesh C5 C6 C7 C8 C9 C10 C11 C12 C Wrapping mesh D126 D196 D283 D385 D503 D636 D785 D950 D1131 D

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