strucsstural design notfdsffdes.pdf

8/8/2019 Strucsstural Design Notfdsffdes.pdf

1/10

CONCRETE

NOMINAL MAXIMUM SIZE OF COARSE AGGREGATE SHALL NOT BE LARGER THAN:

- 1/5 the narrowest dimension between side forms

- 1/3 the depth of slabs

- ¾ the minimum clear spacing between individual reinforcing bars or wires, bundles ofbars, or prestressing tendons or ducts

DEFORMED REINFORCEMENTS

- ASTM A 184 – Fabricated Deformed Steel Bar Mats- ASTM A 185 – Steel Welded Wire Fabric, Plain- ASTM A 496 – Steel Wire, Deformed- ASTM A 497 – Steel Welded Wire Fabric, Deformed- ASTM A 615M – Deformed and Plain-Billet Steel Bars- ASTM A 616M – Rail-Steel Deformed and Plain Bars-

ASTM A 617M –

Axle-Steel Deformed and Plain Bars- ASTM A 706M – Low-Alloy Steel Deformed Bars- ASTM A 767M – Zinc-Coated (Galvanized) Steel Bars- ASTM A 775M – Epoxy-Coated Reinforcing Steel Bars- ASTM A 884M – Epoxy-Coated Steel Wire and Welded Wire Fabric- ASTM A 934M – Epoxy-Coated Prefabricated Steel Reinforcing Bars

PRESTRESSING TENDONS

- ASTM A 416M – Steel Strand, Uncoated Seven-Wire- ASTM A 421 – Uncoated Stress-Relieved Steel Wire- ASTM A 722 – Uncoated High-Strength Steel Bar

CURING

- concrete (other than high-early strength) shall be maintained above 10°C and in amoist condition for at least the first 7 days after placement

- high-early strength concrete shall be maintained above 10°C and in a moist conditionfor at least the first 3 days

CONDUITS AND PIPES EMBEDDED IN CONCRETE

- they (including their fittings) shall not displace more than 4% of the area of crosssection when embedded within a column

- they shall not be larger in outside dimension than 1/3 the overall thickness of slab,

wall or beam in which they are embedded- they shall be spaced not closer than 3 diameters or widths on center- conduits, pipes and sleeves may be considered as replacing structurally in

compression the displaced concrete, provided:o they are of uncoated or galvanized iron or steel not thinner than standard

Schedule 40 steel pipeo they have a nominal inside diameter not over 50mm and are spaced not less

than 3 diameters on centers


2/10

- concrete cover shall not be less than 40mm for concrete exposed to earth orweather, or less than 20mm for concrete not exposed to weather or in contact withground

- reinforcement with an area not less than 0.002 times the area of concrete sectionshall be provided normal to the piping

CONSTRUCTION JOINTS

- construction joints in floors shall be located within the middle third of spans of slabs,beams and girders

- joints in girders shall be offset a minimum distance of 2 times the width of intersectingbeams

STANDARD HOOKS

- 180-degree bend plus 4db extension, but not less than 60mm at free end of bar- 90-degree bend plus 12db extension at free end of bar- for stirrup and tie hooks:

o 16mm diameter bar and smaller –

90-degree bend plus 6db extension at free endof bar, or

o 20 and 25mm diameter bar – 90-degree bend plus 12db extension at free end ofbar, or

o 25mm diameter bar and smaller – 135-degree bend plus 6db extension at freeend of bar

MINIMUM BEND DIAMETERS

- bar size of 16mm and smaller (for stirrups and ties) – 4db (inside diameter)- bar size of 10mm through 25mm – 6db- bar size of 28, 32 and 36mm – 8db

SPACING LIMITS FOR REINFORCEMENT

- the minimum clear spacing between parallel bars in a layer shall be db but not lessthan 25mm

- the minimum clear spacing between parallel bars in 2 or more layers shall not be lessthan 25mm between layers

- in spirally reinforced or tied reinforced compression members, clear distancebetween longitudinal bars shall not be less than 1.5db or less than 40mm

- in walls and slabs other than concrete joist construction, primary flexuralreinforcement shall not be spaced farther apart than 3 times the wall or slabthickness, nor farther than 450mm

BUNDLED BARS

- shall be limited to 4 bars in 1 bundle- shall be enclosed within stirrups or ties- bars larger than 36mm diameter shall not be bundled in beams- individual bars within a bundle terminated within the span of flexural members shall

terminate at different points with at least 40db stagger


3/10

- where spacing limitations and minimum concrete cover are based on bar diameterdb, a unit of bundled bars shall be treated as a single bar of a diameter derived fromthe equivalent total area

- minimum concrete cover shall be equal to the equivalent diameter of the bundle, butneed not be greater than 50mm

PRESTRESSING TENDONS AND DUCTS

- center-to-center spacing of pretensioning tendons at each end of a member shall notbe less than 5db for wire, nor 4db for strands

MINIMUM CONCRETE COVER FOR CAST-IN-PLACE CONCRETE (NONPRESTRESSED)

- concrete cast against and permanently exposed to earth – 75mm

- concrete exposed to earth or weather:o 20mm through 36mm diameter bar – 50mmo 16mm diameter bar and smaller – 40mm

- concrete not exposed to weather or in contact with ground:o slabs, walls, joists:

45 to 60mm diameter bars – 40mm 36mm diameter bar and smaller – 20mm

o beams, columns: primary reinforcement, ties, stirrups, spirals – 40mm

o shells, folded plate members: 20mm diameter bar and larger – 20mm 16mm diameter bar and smaller – 12mm

MINIMUM CONCRETE COVER FOR PRECAST CONCRETE

- concrete exposed to earth or weather:o wall panels:

45mm and 60mm diameter bars – 40mm 36mm diameter bar and smaller – 20mm

o other members: 45mm and 60mm diameter bars – 50mm 20mm through 36mm diameter bar – 40mm 16mm diameter bar and smaller – 30mm

- concrete not exposed to earth or in contact with ground:o slabs, walls, joists:

45mm and 60mm diameter bars – 30mm

36mm diameter bar and smaller –

15mmo beams, columns:

primary reinforcement – db but not less than 15mm and need not exceed40mm

ties, stirrups, spirals – 10mmo shells, folded plate members:

20mm diameter bar and larger – 15mm 16mm diameter bar and smaller – 10mm


4/10

MINIMUM CONCRETE COVER FOR PRESTRESSED CONCRETE

- concrete cast against and permanently exposed to earth – 75mm

- concrete exposed to earth or weather:o wall panels, slabs, joists – 25mmo other members – 40mm

- concrete not exposed to earth or in contact with ground:o slabs, walls, joists – 20mmo beams, columns:

primary reinforcement – 40mm ties, stirrups, spirals – 25mm

o shells, folded plate members: 16mm diameter bar and smaller – 10mm other reinforcement – db but not less than 20mm

OFFSET BARS

- slope of inclined portion of an offset bar with axis of column shall not exceed 1 in 6

- portions of bar above and below an offset shall be parallel to axis of column- lateral ties or spirals, if used, shall be placed not more than 150mm from points of

bend- offset bars shall be bent before placement in the forms- where a column face is offset 75mm or greater, longitudinal bars shall not be offset

bent. Separate dowels, lap sliced with the longitudinal bars adjacent to the offsetcolumn faces, shall be provided

SPIRALS

- for cast-in-place construction, size of spirals shall not be less than 10mm diameter

- clear spacing between spirals shall not exceed 75mm or be less than 25mm

- anchorage of spiral reinforcement shall be provided by 1½ extra turns of spiral bar orwire at each end of a spiral unit

- spiral reinforcement shall be lap spliced by 48db but not less than 300mm or welded- in columns with capitals, spirals shall extend to a level at which the diameter or width

of capital is 2 times that of the column- plain bars shall conform to one of the following specifications:

o ASTM A 615Mo ASTM A 616Mo ASTM A 617M

- plain wire shall conform to:o ASTM A 82 – Steel Wire, Plain

TIES

- 10mm diameter lateral ties for longitudinal bars 32mm diameter or smaller- 12mm diameter lateral ties for longitudinal bars 36 diameter and bundled bars- vertical spacing of ties shall not exceed:

o 16db of longitudinal barso 48db of tie barso least dimension of compression member


5/10

- ties shall be arranged that no bar shall be farther than 150mm clear on each sidealong the tie

- ties shall be located vertically not more than ½ a tie spacing above the top of footingor slab in any story

- where beams or brackets frame from 4 directions into a column, termination of tiesnot more than 75mm below reinforcement in shallowest of such beams or bracketsshall be permitted

SHRINKAGE AND TEMPERATURE REINFORCEMENT

- shrinkage and temperature reinforcement shall be spaced not farther apart than 5times the slab thickness, or 450mm

- spacing of prestressed tendons shall not exceed 1.80m

T-BEAM CONSTRUCTION

- the flange and web shall be built integrally or otherwise effectively bonded together- width of slab effective as a T-beam flange on each side of the web shall not exceed:

o ¼ the span length of the beam,o 8 times the slab thickness, oro ½ the clear distance to the next web

- for beams with a slab on one side only, the effective overhanging flange width shallnot exceed:o 1/12 the span length of the beam,o 6 times the slab thickness, oro ½ the clear distance to the next web

- transverse reinforcement shall be spaced not farther apart than 5 times the slabthickness, nor 450mm

JOIST CONSTRUCTION

- ribs shall not be less than 100mm in width and shall have a depth of not more than3½ times the minimum width of rib

- clear spacing between ribs shall not exceed 750mm- slab thickness over permanent fillers shall not be less than 1/12 the clear distance

between ribs nor less than 40mm- when removable forms or fillers are used, slab thickness shall not be les than 1/12

the clear distance between ribs, or less than 50mm- where conduits or pipes are embedded within the slab, slab thickness shall be at

least 25mm greater than the total overall depth of the conduits or pipes at any point

REQUIRED STRENGTH

- dead load and live loado U = 1.4D + 1.7L

- dead load, live load and wind loado U = 0.75 (1.4D + 1.7L + 1.7W)o U = 0.9D + 1.3W

- dead load, live load and earthquake loado U = 1.3D + 1.1L + 1.1Eo U = 0.99D + 1.1E


6/10

STRENGTH-REDUCTION FACTOR

- flexure without axial load, 0.90- axial tension and axial tension with flexure, 0.90- axial compression and axial compression with flexure:

o spiral reinforced, 0.75o tie reinforce, 0.70

- shear and torsion, 0.85

- bearing on concrete, 0.70- post-tensioned anchorage zones, 0.85

MINIMUM THICKNESS OF NONPRESTRESSED BEAMS OR ONE-WAY SLABS UNLESSDEFLECTIONS ARE COMPUTED (members are not supporting or attached to partitions orother construction likely to be damaged by large deflections)

- solid one-way slabs:o simply supported, L/20o one end continuous, L/24o both ends continuous, L/28o cantilever, L/10

- beams or ribbed one-way slabs:o simply supported, L/16o one end continuous, L/18.5o both ends continuous, L/21o cantilever, L/8

- for Fy other than 415Mpa, the values shall be multiplied by (0.4 + Fy/700)

DISTANCE BETWEEN LATERAL SUPPORTS OF FLEXURAL MEMBERS

- spacing of lateral supports for a beam shall not exceed 50 times the least width b of

compression flange or face

LIMITS FOR REINFORCEMENT OF COMPRESSION MEMBERS

- minimum number of longitudinal bars in compression members shall be 3 for barswithin triangular ties, 4 for bars within rectangular or circular ties, and 6 for barsenclosed by spirals

SPACING LIMITS FOR SHEAR REINFORCEMENT

-

shall not exceed d/2 in non-prestressed members and 3/4h in prestressed membersor 600mm

SPLICES

- lap splices shall not be used for bars larger than 36mm diameter- lap splices of bars in a bundle shall be based on the lap splice length required for

individual bars within the bundle- individual bar splices within a bundle shall not overlap


7/10

- entire bundles shall not be lap spliced- bars spliced by non-contact lap splices in flexural members shall not be spaced

transversely farther apart than 1/5 the required lap splice length, or 150mm- splices shall be staggered at least 600mm

WALLS

- minimum ratio of vertical reinforcement area to gross concrete area shall be:o 0.0012 – deformed bars not larger than 16mm diameter with a specified yield

strength not less than 420Mpa, oro 0.0015 – for other deformed bars, oro 0.0012 – for welded wire fabric (plain or deformed)

- minimum ratio of horizontal reinforcement area to gross concrete area shall be:o 0.0020 – deformed bars not larger than 16mm diameter with a specified yield

strength not less than 420 Mpa, oro 0.0025 – for other deformed bars, oro 0.0020

– for welded wire fabric (palin or deformed)

- in addition to the minimum reinforcement required, not less than 2-16mm diameterbars shall be provided around all window and door openings. Such bars shall beextended to develop the bar beyond the corners of the openings but not less than600mm

NON-BEARING WALLS

- thickness shall not be less than 100mm, or not less than 1/30 the least distancebetween members that provide lateral support

MINIMUM FOOTING DEPTH

- depth of footing above bottom reinforcement shall not be less than 150mm forfootings on soil, or not less than 300mm for footings on piles

TRANSVERSE REINFORCEMENT (HOOPS)

- the first hoop shall be located not more than 50mm from the face of a supportingmember

- maximum spacing of the hoops shall not exceed:o d/4o

8 times the diameter of the smallest longitudinal baro 24 times the diameter of the hoop barso 300mm

- where hoops are not required, stirrups shall be placed at no more than d/2throughout the length of the member


8/10

STRUCTURAL STEEL

LIMITING SLENDERNESS RATIOS

- for members whose design is based on compressive force, the slenderness ratio

preferably should not exceed 200- for members whose designed is based on tensile force, the slenderness ratio

preferably should not exceed 300

ALLOWABLE STRESSES

- for tension in structural steel in terms of gross area, 0.60Fy- for tension in structural steel based on effective net area, 0.50Fu- for tension on pin-connected members based on net area, 0.45Fy- for tension on eyebars on the body area, 0.60Fy- for flexural members with compact sections, Fb = 0.66Fy- for flexural members with non-compact sections, Fb = 0.60Fy

PIN-CONNECTED MEMBERS

- minimum net area beyond the pinhole, parallel to the axis of the member, shall not beless than 2/3 of the net area across the pinhole

- width of the body of an eyebar shall not exceed 8 times its thickness- pin diameter shall not be less than 7/8 times the eyebar width- pinhole diameter shall be no more than 0.8mm greater than the pin diameter

SHEAR CONNECTORS

- shear connectors shall have at least 25mm of lateral concrete cover

- diameter of studs shall not be greater than 2½ times the thickness of the flange to

which they are welded- minimum center-to-center spacing of stud connectors shall be 6 diameters along the

longitudinal axis and 4 diameters transverse to the longitudinal axis maximum center-to-center spacing of stud connectors shall not exceed 8 times the total slab thickness

WELDS

- weld access holes shall have a length from the toe of the weld preparation not lessthan 1½ times the thickness of the material in which the hole is made

- groove welds:

o effective area = effective length of the weld x effective throat thicknesso effective length = width of the part joinedo effective throat thickness of a complete-penetration groove weld = thickness of

the thinner part joinedo minimum effective throat thickness of partial-penetration groove welds =

3mm (thicker part joined to 6mm inclusive) 5mm (thicker part joined over 6 to 12mm) 6mm (thicker part joined over 12 to 20mm) 8mm (thicker part joined over 20 to 38mm)


9/10

10mm (thicker part joined over 38 to 57mm) 12mm (thicker part joined over 57 to 150mm) 16mm (thicker part joined over 150mm)

o effective throat thickness of a flare groove weld = flare bevel groove, 5/16R flare V-groove, ½R

- fillet welds:

o effective area of fillet welds = effective length x effective throat thicknesso effective throat thickness of a fillet weld = shortest distance from the root of the

joint to the face of the diagrammatic weldo minimum size of fillet welds =

3mm (thicker part joined to 6mm inclusive) 5mm (thicker part joined over 6 to 12mm) 6mm (thicker part joined over 12 to 20mm) 8mm (thicker part joined over 20mm)

o maximum size of fillet welds along edges = not greater than the thickness of the material (material less than 6mm

thick) not greater than the thickness of the material minus 1.6mm (material

6mm or more in thickness)o minimum effective length of a fillet weld designed on the basis of strength shall

not be less than 4 times its nominal sizeo if greater than 4 times its nominal size, the size of the weld should not exceed ¼

its effective lengtho effective length of any segment of intermittent fillet welding shall not be less than

4 times the weld size, with a minimum of 38mmo in lap joints, minimum lap shall be 5 times the thickness of the thinner part joined,

but not less than 25mmo slide or end fillet welds terminating at ends or sides, respectively, of parts or

members shall, wherever practicable, be returned continuously around thecorners for a distance not less than 2 times the nominal size of the weld

- plug and slot welds:

o diameter of the hole for a plug weld shall not be less than the thickness of thepart containing it plus 8mm, nor greater than the minimum diameter plus 3mm or2¼ times the thickness of the weld

o minimum spacing of lines of slot welds in a direction transverse to their lengthshall be 4 times the width of the slot

o minimum center-to-center spacing in a longitudinal direction shall be 2 times thelength of the slot

o length of the slot shall not exceed 10 times the thickness of the weldo width of the slot shall not be less than the thickness of the part containing it plus

8mm, nor shall it be larger than 2¼ times the thickness of the weldo thickness of plug or slot welds in material 16mm or less thick = thickness of the

materialo

thickness of plug or slot welds in material over 16mm thick = ½ the thickness ofthe material but not less than 16mm


10/10

FASTENERS

- distance between centers of standard, oversized or slotted fastener holes shall notbe less than 2 2/3 times the nominal diameter of the fastener

- maximum distance from the center of any rivet or bolt to the nearest edge of parts incontact shall be 12 times the thickness of the connected part, but shall not exceed150mm

CAMBER

- trusses of 24.4m or greater span generally shall be cambered for approximately thedead-load deflection

- crane girders of 22.9m or greater span generally shall be cambered for approximatelythe dead-load deflection plus ½ the live-load deflection

strucsstural design notfdsffdes.pdf

Documents