14Installation of road signs#

14.1General#

This Clause describes the work to be carried out for the installation of regulatory, warning, hazard, direction and information signs under the Contract.

14.2Materials and fabrication#

14.2.1Fabrication#

14.2.1.1Registered fabricator#

Steelwork used to support road signs shall be fabricated only by an approved fabricator. The requirements of registration are outlined in document SCM-P-015. For copy of this document refer to contract details in Clause 1.

14.2.1.2Fabrication standard#

Except where otherwise stated in this Technical Specification, all fabrication shall be carried out in accordance with the requirements of MRTS78 Fabrication of Structural Steelwork.

14.2.1.3Welding personnel#

All welders shall:

1. a)Satisfy conditions A & B of Clause 4.12.2 of AS/NZS 1554.1.
2. b)For SP welding, have a trade qualification, or demonstrate competence equivalent to a trade qualification, and
3. c)Welding personnel who do not conform to the requirements of (b) then the following shall be met:
4. i.welders shall be permitted to undertake only fillet welds up to a maximum of 8 mm
5. ii.a representative of Transport and Main Roads Structures Construction Materials shall be present when macro samples are prepared to show conformance with Clause 4.12.2 (b) of AS/NZ 1554.1. The fabricator shall be responsible for covering all costs associated with witnessing the production of the macro samples; Hold Point 4 and
6. iii.welder re-certification is required every 12 months and the department reserves the right to withdraw welder certification if welding is below the department’s requirements.

14.2.2Materials general#

All steel used for the fabrication of components and supports shall comply with the relevant Standard. These include (but not limited) to the following:

1. a)hot-rolled section - AS/NZS 3679.1
2. b)mild steel plate - AS/NZS 3678
3. c)cold-formed section - AS/NZS 4600, and
4. d)hollow sections - AS/NZS 1163 Grade LO.

Fabrication of steel members shall conform to the requirements of MRTS78 Fabrication of Structural Steelwork.

All steelwork shall be hot-dipped galvanised after fabrication in accordance with the requirements of MRTS78 Fabrication of Structural Steelwork.

14.2.3Posts#

Posts for road signs shall generally be circular hollow section or rectangular hollow section unless specifically shown otherwise in the design documentation.

For posts with a total area of attached signs less than 1.0 m² with a maximum sign width of 1000 mm, posts shall be 60.3 OD x 2.9 mm CHS Grade C350 LO to AS/NZS 1163 and they shall comply with the details for low risk or frangible support posts with the base deformed to prevent rotation as shown on Standard Drawing 1368. Footings shall comply with Standard Drawing 1363. The location and height of signs shall comply with the requirements of the Queensland Manual of Uniform Traffic Control Devices (MUTCD).

For other signs, the size of posts and numbers of posts for each sign shall be as shown in the design documentation. CHS and RHS shall be Grade 250/350/450 LO to AS/NZS 1163 as shown in the design documentation.

The spacing of posts and footings for posts shall be as shown in the design documentation.

Slip bases and fuse plates for posts, where required, shall be fabricated in accordance with the details shown on Standard Drawings 1365 and 1368.

All posts shall be hot-dipped galvanised in accordance with the requirements of MRTS78 Fabrication of Structural Steelwork.

The top of posts shall be fitted with a hot-dipped galvanised steel cap.

14.2.4Connection straps#

Connection straps for installation of multi-post signs shall be fabricated from steel to the dimensions and in accordance with the requirements shown on Standard Drawing 1364.

Connection straps for installation of single-post signs shall be fabricated from steel to the dimensions and in accordance with the requirements shown on Standard Drawing 1368.

14.2.5Brackets#

Brackets for installation of fingerboards, geographical feature and street name signs shall be fabricated in accordance with the requirements shown on Standard Drawing 1295.

14.2.6Fixings#

Bolts, nuts and steel washers shall be hot-dipped galvanised and shall conform to the requirements of MRTS278 Supply of Structural Fasteners.

Bolts for slip bases shall be high strength bolts, Grade 8.8, and shall be supplied with a nut and five washers per bolt.

In special circumstances and where shown on the Drawings, stainless steel bolts, nuts and washers shall be used.

14.2.7Sign frames#

Sign frames shall be fabricated in accordance with the details shown in the design documentation.

The size of the frame shall be checked prior to fabrication to ensure that it can be hot-dipped galvanised after fabrication. The fabrication details shown in the design documentation shall not be amended unless it can be proven that a frame is too large to allow hot-dipped galvanising in Queensland. Double dipping shall be allowed.

14.2.8Anchor bolts#

Anchor bolts for cantilever and gantry signs shall be fabricated as shown in the design documentation. Only metric threads shall be used. All anchor bolts shall be provided with one nut and one steel washer.

Anchor bolts, nuts and washers shall be hot-dipped galvanised.

Anchor bolts shall be provided with a substantial steel template for use in locating the anchor bolts during placement of concrete.

14.2.9Handling, transport and storage#

All sign components shall be handled, transported and stored in such a manner as to prevent damage to members and/or coatings. Steel slings and tie downs shall not be used during handling and transport. Sign posts and frames shall be stored on the Site on timber packing well clear of the ground and shall be kept free of dirt, grease and other foreign matter. Components shall be so arranged as to be free draining. Sign faces shall be stored vertically on edge either in a rack or in such a way that they are supported vertically. Any banding around signs shall be cut and removed on delivery to site. Signs stored indoors may be left in their original transport packaging provided the storage area is ventilated and the packaging is not wet. Signs stored outside shall be unwrapped from their transport packaging. Direction and information signs shall be stored avoiding pressure points on sign faces and allowing air circulation between sign faces to prevent a build-up of moisture.

14.3Construction of footings#

Concrete footings for road sign posts shall be constructed:

• a) where specific details for individual signs are shown in the design documentation, in accordance with such details
• b) for circular hollow section and rectangular hollow section posts, in accordance with the details shown on Standard Drawing 1363, or otherwise.

Holes for sign footings shall be excavated to a minimum size as shown in the design documentation. Circular holes shall be excavated using an earth auger. Anchor bolts for cantilever and gantry signs shall be assembled into the positioning template which shall be held firmly in place during placement of the concrete. Concrete shall comply with the requirements of MRTS70 Concrete. Unreinforced concrete shall not be less than grade N20/20 and reinforced concrete shall not be less than grade N32/20. For frangible support posts, the Administrator can substitute the nominated concrete (N20/20) concrete with a departmental registered proprietary bagged concrete product which has a 28 day compressive strength of not less than 40 MPa. The proprietary bagged concrete shall be mixed, placed and cured as per the manufacturer's requirements. Steel reinforcing shall comply with the requirements of MRTS71 Reinforcing Steel.

For low risk or frangible support posts, are generally installed in locations with very small volumes of concrete required to install the sign. For these low risk signs, the department is prepared to allow installers to use a proprietary bagged product which can be mixed at the installation site, and therefore, reduce the cost of opening a concrete batch plant for a small load of concrete. The departmental approved proprietary bagged products can be found under the approved Product Index for Bridges and Other Structures on the departmental website.

14.4Erection of signs#

14.4.1General#

Erection of road signs shall be a Witness Point 1

14.4.2Location#

Signs shall be erected at the locations shown in the design documentation or, where not so shown, in accordance with the requirements of the MUTCD. The location of posts, transverse to the road centreline shall be in accordance with the details shown in the design documentation. Orientation of signs shall be in accordance with the requirements of Clause 1.12.5.3 of Part 1 of the MUTCD.

14.4.3Posts#

Sign posts shall be erected true to vertical. Slip bases, where required, shall be assembled strictly in accordance with the details shown on Standard Drawing 1363, 1365, or 1368 (as required). High strength bolts shall be tensioned as detailed on the relevant Standard Drawing.

14.4.4Frames#

Frames for cantilever and gantry signs shall be erected onto the anchor bolts on temporary packers set to the required level. Final adjustments shall be made so that the sign column is vertical. Once vertical the anchor bolts shall be snug tensioned. The base plates shall be packed with cement mortar consisting of one part of type GP cement and three parts of clean sharp sand with sufficient water added to form a dry packing mortar. All materials shall comply with MRTS70 Concrete. The edges of the mortar shall be trimmed neatly to a constant bevel. Once the mortar has achieved the required strength, the temporary packers shall be removed and the nuts on the anchor bolts shall be re-tightened. The mortar where the temporary packers were located shall be repaired with cement mortar consisting of one part of type GP cement and three parts of clean sharp sand with sufficient water added to form a dry packing mortar. All materials shall comply with MRTS70 Concrete.

14.4.5Sign faces (erection)#

When all other erection has been completed, the sign faces shall be checked for message (including spelling, shape, size, layout and colours and then installed on the posts and/or frame. Sign faces shall be attached to posts or frames at all intersections between the stiffener rails and the post or frame. Stiffener rails shall be attached to posts with saddles and cup head bolts and nuts. Saddles are not required where sign faces are attached to frames. Where sign faces are supplied in sections for modular erection, sections shall be connected together with hexagonal-headed bolts, cup head bolts, plates, nuts and washers. Extreme care shall be taken during erection of sign faces so that the coatings are not damaged and the substrate is not dented.