Specification on Hambro D500
PART I - GENERAL
The supplier shall:
(a) Furnish all labor, materials, equipment and services
necessary for, and incidental to, the fabrication of the
Hambro Composite Floor System in accordance with
these specifications and applicable drawings. Hambro
Steel joists and Rollbar shall be manufactured and
marketed by Hambro or their authorized representatives.
(b) Fully coordinate the Hambro Composite Floor
System with the other structural, mechanical, electrical
and architectural components of the buildings.
PART II - TYPICAL SPECIFICATION
All fabrication shall be in strict accordance with the Hambro
Shop Standard Practice, using steel conforming to Canadian
Standards Association CAN/CSA G40.21-04 or similar ASTM
Standards, or their engineering equivalent capacities.
Flexural design shall be by the Limit States Design
method and as described in the Hambro literature. The
slab shall be designed in accordance with CAN/CSA A23.304
“Design of Concrete Structures for Buildings”, the
top chord shall be designed in accordance with
CAN3-S136-M94 “Cold-Formed Steel Structural Members”,
the bottom chord and webs shall be designed in
accordance with CAN/CSA S16.01 - “Steel Structures for
Buildings (Limit States Design)”.
(a) All welding materials and methods used for fabrication
shall be in accordance with the requirements of
the Canadian Welding Bureau.
(b) All field welders shall be certified, qualified operators
in accordance with the requirements of CWB for the
materials and methods being used, except that
Hambro joist repairs or modifications that may be
required may be done by factory approved personnel.
(a) Submit detailed erection drawings to the Architect,
Engineer or the General Contractor for approval
showing material lists, mark numbers, types, locations,
and spacing of all joists and accessories. Show
method of attachment of the joist to supporting
members. Contract drawing notes relative to the
Hambro system shall be considered a part of this
specification as though fully set forth herein.
(b) Shop drawings prepared only from approved erection
drawings shall be used for fabrication and erection.
(c) Figured dimensions only shall be used, scaling
drawings shall not be permitted.
2.5 HANDLING AND STORAGE
Care shall be exercised at all times to avoid damage to
Hambro joists through careless handling during unloading,
storing and erecting.
PART III - PRODUCTS
(a) Hambro joists:
1- All composite joists shall be fabricated in accordance with Section 2.1 and 2.2 of these Specifications.
2- Top chord member shall act as a continuous shear connector of cold rolled steel, minimum 13 gauge with Fy = 350 MPa (50 ksi) minimum.
3- Bottom chord member shall consist of either hot rolled angles with Fy = 380 MPa (55 ksi) minimum or cold rolled angles of equal capacities of steel.
4- Web members shall consist of minimum 13 mm (1/2”) diameter hot rolled bars of Fy = 350 MPa (50 ksi) minimum.
5- All composite joists shall be shop painted with a rust inhibitive primer. According to CISC/CPMA Standard 1-73a one coat paint.
(b) Rollbar shall be designed specifically to support 10 mm (3/8”) to 15 mm (5/8”) plywood forms, a 2 kPa (40 psf) construction load and slab weight until the
slab has cured sufficiently (concrete cylinder strength of 3.5 MPa (500 psi)), and act as temporary bridging and spacers for Hambro composite joists.
(c) Standard bearing shoes shall be angle shape 100 x 50 x 6 x 120 (4” x 2” x 1/4” x 4 3/4”) wide, unless otherwise noted.
(d) Slab reinforcement shall be minimum 152 x 152 MW13.3 x MW13.3 ( 6 x 6 - 8/8) welded wire fabric, with Fy = 400 MPa (60 ksi) minimum unless otherwise required by structural engineer.
(e) Forms shall be 1 220 mm (4’-0”) or 1 500 mm (4’-11”) plywood sheets, and may be 10 mm (3/8”) to 15 mm (5/8”) thick.
1- Minimum ultimate compressive strength f’c = 20 MPa (3 000 psi) at 28 days for Hambro design.
2- Standard density i.e. 2 450 kg/m3 (145 pounds / ft3).
3- Maximum size coarse aggregate: 19 mm (3/4”).
(a) Fabrication shall be in accordance with the Hambro Shop Standard Practice.
(b) The joist top chord shall be fabricated to allow for 40 mm (1 1/2”) embedment into the concrete slab.
(c) Provide Hambro joist bottom chord ceiling extensions unless otherwise noted.
(d) After installation, permissible Hambro joist sweep shall be 25 mm (1”) in 6 m (20’-0”).
(e) Hambro joists shall be fabricated with an appropriate camber to suit span and slab thickness. The camber shall be designed according to the non-composite
3.3 QUALITY CONTROL
Joist shall be manufactured in a fabricator’s facility having a continuous quality control program. Theinspection shall include checking of size, span, assembly and weld.
PART IV - EXECUTION
(a) Installation shall be in accordance with the latest Installation Manual for the Hambro Composite Floor System, approved erection drawings and any amendments which may be issued by the manufacturer.
(b) All joists shall be erected in such a manner so that they are vertical, level and plumb and at the proper elevation. Any shimming that may be required shall be done with metal.
(c) Special conditions requiring top and/or bottom bracing shall be shown on erection drawings prepared by supplier.
(d) Welded Wire Fabric - Lapping shall be in accordance with the provisions of CAN/CSA A23.3-04 and Hambro construction drawings.
(e) End anchorage - Joist shoes shall be properly welded, anchored or embedded as per engineer’s or architect’s drawings.
(f) Concreting Practice
1- Do not pour concrete in excess of the slab thickness stated on the erection drawings.
2- Do not drop large bucket loads in concentrated areas over Hambro joists. Lightly vibrate concrete
3- Construction joints made parallel to the joists should be made midway between the joists but never closer than 150 mm (6”) to the top chord. Construction joints made perpendicular to the joists should be located over the supporting wall or beam.
4- It is recommended that the following publications be followed:
(a) CAN/CSA A23.3-04 “Design of Concrete Structures for Buildings”.
(b) CAN/CSA A23.2-04 “Methods of Test for Concrete”.
(c) CAN/CSA A23.1-04 “Concrete Materials and Methods of Concrete Construction”.
(g) Stripping - Under normal conditions form work may be stripped at such time as the concrete has reached a cylinder strength of 3.5 MPa (500 psi).
(h) Construction Loads
1- Bundles of plywood or roll bars should not be placed on joist system but rather on supporting walls or beams.
2- During construction, the minimum non-composite joist capacity for a 70 mm (2 3/4”) slab and joist spacing of 1 251 mm (4’-1 1/4”) on center, shall be 3.5 kN/m (240 plf). Joists spaced at greater than 1 251 mm (4’-1 1/4”) on center shall have their non composite capacity adequately increased to carry the additional load.
Construction loads may be applied when the concrete has reached a cylinder strength of 7 MPa (1000 psi).
(i) Minimum joist bearing shall be as follows:
1- Steel support: 65 mm (2 1/2”) for 75 mm (3”) shoe 90 mm (3 1/2”) for 100 mm (4”) shoe.
2- Masonry, concrete, wood and metal stud support: 90 mm (3 1/2”). Bearing surface of supporting units to comply with applied shoe end reaction, based on minimum supplied bearing area of 107 cm2 (16.6 in2).