Structural Terms and Standards for Concrete and Steel IV

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 be less 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 less than 1½ times the thickness of the material in which the hole is made
- groove welds:
          * effective area = effective length of the weld x effective throat thickness
          * effective length = width of the part joined
          * effective throat thickness of a complete-penetration groove weld = thickness of the thinner part joined
          * 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)
                    - 10mm (thicker part joined over 38 to 57mm)
                    - 12mm (thicker part joined over 57 to 150mm)
                    - 16mm (thicker part joined over 150mm)
          * effective throat thickness of a flare groove weld =
                    - flare bevel groove, 5/16R
                    - flare V-groove, ½R

- fillet welds:
          * effective area of fillet welds = effective length x effective throat thickness
          * effective throat thickness of a fillet weld = shortest distance from the root of the joint to the face of the diagrammatic weld
          * 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)
          * 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)
          * minimum effective length of a fillet weld designed on the basis of strength shall not be less than 4 times its nominal size
          * if greater than 4 times its nominal size, the size of the weld should not exceed ¼ its effective length
          * effective length of any segment of intermittent fillet welding shall not be less than 4 times the weld size, with a minimum of 38mm
          * in lap joints, minimum lap shall be 5 times the thickness of the thinner part joined, but not less than 25mm
          * slide or end fillet welds terminating at ends or sides, respectively, of parts or members shall, wherever practicable, be returned continuously around the corners for a distance not less than 2 times the nominal size of the weld

- plug and slot welds:
          * diameter of the hole for a plug weld shall not be less than the thickness of the part containing it plus 8mm, nor greater than the minimum diameter plus 3mm or 2¼ times the thickness of the weld
          * minimum spacing of lines of slot welds in a direction transverse to their length shall be 4 times the width of the slot
          * minimum center-to-center spacing in a longitudinal direction shall be 2 times the length of the slot
          * length of the slot shall not exceed 10 times the thickness of the weld
          * 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 weld
          * thickness of plug or slot welds in material 16mm or less thick = thickness of the material
          * thickness of plug or slot welds in material over 16mm thick = ½ the thickness of the material but not less than 16mm

FASTENERS

- distance between centers of standard, oversized or slotted fastener holes shall not be 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 in contact shall be 12 times the thickness of the connected part, but shall not exceed 150mm

CAMBER

- trusses of 24.4m or greater span generally shall be cambered for approximately the dead-load deflection
- crane girders of 22.9m or greater span generally shall be cambered for approximately the dead-load deflection plus ½ the live-load deflection

Structural Terms and Standards for Concrete and Steel III

SHRINKAGE AND TEMPERATURE REINFORCEMENT

- shrinkage and temperature reinforcement shall be spaced not farther apart than 5 times 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:
          * 1/4 the span length of the beam,
          * 8 times the slab thickness, or
          * 1/2 the clear distance to the next web
- for beams with a slab on one side only, the effective overhanging flange width shall not exceed:
          * 1/12 the span length of the beam,
          * 6 times the slab thickness, or
          * 1/2 the clear distance to the next web
- transverse reinforcement shall be spaced not farther apart than 5 times the slab thickness, nor 450mm

Structural Terms and Standards for Concrete and Steel II

PRESTRESSING TENDONS AND DUCTS

- center-to-center spacing of pretensioning tendons at each end of a member shall not be 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:
          * 20mm through 36mm diameter bar – 50mm
          * 16mm diameter bar and smaller – 40mm
- concrete not exposed to weather or in contact with ground:
          * slabs, walls, joists:
                    - 45 to 60mm diameter bars – 40mm
                    - 36mm diameter bar and smaller – 20mm
          * beams, columns:
                    - primary reinforcement, ties, stirrups, spirals – 40mm
          * shells, folded plate members:
                    - 20mm diameter bar and larger – 20mm
                    - 16mm diameter bar and smaller – 12mm

Structural Terms and Standards for Concrete and Steel I

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
- 3/4 the minimum clear spacing between individual reinforcing bars or wires, bundles of bars, 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

TERMINOLOGIES: Structural Terms II

ACCESS FLOOR SYSTEM - is an assembly consisting of panels mounted on pedestals to provide an under-floor space for the installations of mechanical, electrical, communications or similar systems to serve as an air-supply or return-air plenum.

AGRICULTURAL BUILDING - is a structure designed to house farm implements, hay, grain, poultry, livestock or other horticultural products. The structure shall not be a place of human habitation or a place of employment where agricultural products are processed, treated or packaged, nor shall it be a place used by the public.

ALLOWABLE STRESS DESIGN METHOD - is a method of proportioning structural elements such that computed stresses produced in the elements by the allowable stress load combinations do not exceed specified allowable stress (also called working stress design).

ASSEMBLY BUILDING - is a building or portion of a building for the gathering together of 50 or more persons for such purposes as deliberation, education, instruction, worship, entertainment, amusement, drinking or dining, or awaiting transportation.

AWNING - is a shelter supported entirely from the exterior wall of a building.

BALCONY, EXTERIOR, - is an exterior floor system projecting from a structure and supported by that structure, with no additional independent supports.

DEAD LOADS - consist of the weight of all materials and fixed equipment incorporated into the building or other structure.

DECK - is an exterior floor system supported on at least two opposing sides by an adjoining structure and/or posts, piers, or other independent supports.

TERMINOLOGIES: Grading and Earthwork Terms

APPROVAL - shall mean that the proposed work or completed work conforms to this section in the opinion of the building official.

AS GRADED - is the extent of surface conditions on completion of grading.

BEDROCK - is in-place solid rock.

BENCH - is a relatively level step excavated into earth material on which fill is to be placed.

BORROW - is earth material acquired from an off-site location for use on grading on a site.

TERMINOLOGIES: Structural Terms

ADDITION - is an extension or increase in floor area or height of a building or structure.

ALLOWABLE STRESS DESIGN - is a method of proportioning structural elements such that computed stresses produced in the elements by the allowable stress load combinations do not exceed specified allowable stress (also called working stress design).

ALTER or ALTERATION - is any change, addition or modification in construction or occupancy.

APPROVED - as to materials and type of construction, refers to approval by the building official as the result of investigation and tests conducted by the building official, or by reason of accepted principles or tests by recognized authorities, technical or scientific organizations.