17. Railing
[This section requires effective proof reading and altered as deemed necessary. It also requires a critical review in the light of more current practice, codes and specifications.]
17.1 General
This section applies to the handling and erection of metal pedestrian and traffic guard rails.
This section does not apply to W-Beam guardfence.
Supply and fabricate non-ferrous railing in compliance with this section.
Supply and fabricate ferrous railing in compliance with this section in addition to the requirements of the Clauses for Fabrication of Steelwork and Protective Treatment of Steelwork.
Do not incorporate any railing components in the works which are damaged in any way, or which are rejected due to nonconformance with any requirement of this specification.
Remove and replace any such components to the Superintendent's satisfaction. Assume responsibility for, and pay all resulting costs.
17.2 Standards
Conform to the following standards unless specified otherwise:
AS 1231 Aluminium and aluminium alloys - Anodised oxidation coatings
AS 1664 Aluminium structures – Limit state design
AS 1665 Welding of aluminium structures
AS/NZS 1866 Aluminium and aluminium alloys - Extruded rod, bar, solid and hollow shapes
AS 1874 Aluminium and aluminium alloys - Ingots and castings
AS 2039 Methods for testing anodic oxidation coatings on aluminium and aluminium alloys
Comply with the additional requirements of this Specification.
Comply with the requirements of this specification if they contradict clauses in the above standards.
17.3 Erection
Handle and store railing material with care.
Provide installed railing that is clean and free of grease, dirt and other contaminants.
Comply with the following erection tolerances:
- Deviation from the line shown on the Drawings + or - 20mm
- Deviation from a smooth line and grade + or - 3mm in 2m
- Joint gaps between components - 0 to + 3mm
- Alignment of railing posts + or - 0.01 mm/m
Do not follow any irregularity of deck.
Assume posts are vertical unless otherwise shown on the drawings.
Do not tighten any bolts or place any mortar beneath base plates until:
- all the railing is in place,
- the railing is at final line and level, and,
- the installation has been inspected and approved.
Use mortar comprising one part Portland cement to three of clean sand mixed with water to a stiff consistency beneath base plates unless noted otherwise on the drawings.
Tamp the mortar to a dense mass beneath the baseplate.
Neatly clean excess or unsightly mortar from all adjacent concrete surfaces.
[Insert the following clauses for aluminium rails.]
Immediately clean excess mortar or mortar droppings from aluminium surfaces.
Recess mortar 3mm from the edge of aluminium baseplates (to prevent water accumulation).
Apply a coat of an approved zinc chromate primer to all surfaces of aluminium posts and rails that are in contact with concrete.
Do not use bare steel wire rope slings on components.
17.4 Steel Bridge Railing
Jig manufacture all components of steel railings unless otherwise approved.
17.5 Aluminium Bridge Railings
17.5.1 Materials
Use aluminium alloy AP 405-T4 in castings.
Use aluminium alloy 6061-T6 extrusions.
17.5.2 Testing of Materials
Supply evidence satisfactory to the Superintendent that all materials or parts conform with this Specification.
Supply test certificates of the results of mechanical tests and chemical analysis (where applicable) of the material or parts used in the work.
17.5.3 Testing of Posts
Conduct all testing in the presence of the Superintendent.
Test 10 percent of posts at random with horizontal forces of 20.0 kN at right angles to the rail direction and 5 kN parallel to the rail directions.
Following the test, inspect each post for cracks.
Reject all cracked posts.
Test all posts if any cracks are found.
17.5.4 Dimensional Tolerances of Fabricated Components
Comply with "Aluminium Standards and Data - Wrought Products", published by the Aluminium Development Council of Australia.
Produce castings having dimensions within + or - 0.5mm of those specified.
17.5.5 Fasteners
Apply lanoline-based grease to the shafts and threads of set screws and bolts prior to fitting them to the aluminium components.
Use a torque wrench to tighten set screws.
Do not tighten beyond the specified torque range.
17.5.6 Surface Finish
Reject all castings that are:
- rough,
- cracked, or,
- exhibit shrinks, porosity, or blow-holes.
Grind mould parting lines (in excess of 1 mm high) flush.
Reject all components with scored, gouged, or discoloured surfaces.
Surface finish shall be standard structural mill finish on all posts, rails and splices.
[Alternative clauses where anodised surface finish is specified.]
Anodise all aluminium components after fabrication providing them with a Grade 4 film of 25 micrometres (AA 25) minimum thickness having the maximum hardness and scratch resistance.
[Delete or complete the following clauses as required -]
Provide a matt, low-reflectivity, medium-gold coloured anodised surface finish.
Supply two samples of each proposed anodised aluminium surface finish to the Superintendent for approval.
Do not order aluminium without approval of the samples.
The samples will be used for the quality control of anodised surface finishes: surfaces not falling within the range represented by the approved samples will be rejected.
17.6 Inspection – hold point
Uninspected work shall be rejected.
Hold Point - Obtain the Superintendent's inspection and/or approval of each of the following components of the work:
- fabrication details,
- fabricated components in the fabrication shop,
- all surfaces of components immediately prior to the application of protective coatings,
- completely installed and aligned railing prior to mortaring beneath base plates and tightening hold-down bolts,
- the finished railing.
The Superintendent will carry out the inspection within two weeks of receiving a written request.
Allow and facilitate the Superintendent's access to the site of works and fabrication areas at all reasonable times for the purposes of inspecting work.
Provide, free of charge, all facilities and labour needed by the Superintendent for the inspection.
<DoI Bridgeworks Master – Dec 2012
RAILING