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Standard specification for road works 2015/2016



Standard specification for road works 2015/2016


Standard specification for road works; Reports; PublicationNT




Made available via the Publications (Legal Deposit) Act 2004 (NT).; Check within Publication or with content Publisher.


miscellaneous provisions ■ provision for traffic ■ clearing grubbing and rehabilitation ■ earthworks ■ conformance testing ■ pavements and shoulders ■ stabilisation ■ spray sealing ■ dense graded asphalt ■ slurry surfacing ■ miscellaneous concrete works ■ drainage works ■ protection works ■ road furniture and traffic control devices ■ pavement marking ■ landscape ■ ducting and conduits ■ traffic control signals ■ traffic counting stations ■ street lighting ■ directional (thrust) boring ■ measurement and payment ■ referenced documents ■ nt climate zones table ■ This document specifies the general standards of materials and workmanship required by the Department of Infrastructure for construction of civil road network assets




Roads -- Northern Territory -- Works -- Periodicals.

Publisher name

Department of Infrastructure

Place of publication



Second edition

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DRAINAGE WORKS STANDARD SPECIFICATION ROADWORKS DoI REFERENCE TEXT December 2015 Page 87 embankment and pavement. The toms shall bear against a sill along the invert and a cap against the crown of the pipe. Provide toms opposite every pipe joint. Cast collars and blocks in one operation. Restrain the culvert prior to constructing the collars or blocks by partially backfilling with bedding around the barrel of the culvert to one-half of the pipe diameter. 12.6.8 Laying Box Culverts Lay precast box culverts on a cast-in-situ reinforced concrete base slab. Ensure concrete base slab exceeds external width of box culverts as shown on the typical details. Butt box culverts firmly together. Cut away lifting hooks and seal over the affected area with an approved epoxy resin. Fill all joints with a stiff mortar firmly rammed into the openings. Remove excess mortar from the barrel of the culvert and apply external joint seals, Densopol HT60 or equivalent, 150 mm wide. 12.6.9 Connection to Existing Systems Witness Point Repair all cut openings and make watertight. Demolish existing headwalls to make way for the extension of the culvert. Clean out new work and existing work affected by the new work. Witness Point Advise superintendent within two days when clean out is completed 12.6.10 Backfill Witness Point Hold Point Witness point - Notify the Superintendent before backfilling where holes or fissures occur in rock trenches. Hold point - Do not place backfill against any in-situ concrete structure until the concrete has attained 80% characteristic strength and approval has been given. Place backfill in layers not exceeding 150 mm compacted thickness. Ensure the maximum difference in height of backfill on each side of a culvert is 300 mm. Backfill around the culvert for the full width of the trench, and for a minimum 300 mm above the top of the culvert, or to subgrade surface if less, with select fill. Backfill the remainder of the trench with standard fill. Stabilise all backfill with 2% cement by mass and compact to 95% relative compaction. Produce a uniform mix. Complete compaction within one hour of adding mixing water. Use compaction equipment which will not damage the culvert and in-situ structures. Carry out conformance testing using the Departments Panel Period Contractors for Testing. Stabilise top 150 mm of backfill, for a distance of 1 m adjacent to culvert headwalls and wing walls, so as to be erosion - resistant. Remove surplus material from the site. Reinstate to subgrade level trenches cut through pavements and other construction by backfilling the trench with stabilised select fill compacted to 95% relative compaction. Construct base/sub-base layers of the pavement in accordance with PAVEMENTS AND SHOULDERS. Reinstate surface. Reinstate trenches cut outside of pavements and other construction by backfilling with standard fill compacted to 90% relative compaction. 12.7 INLET AND OUTLET STRUCTURES AND MAINTENANCE HOLES Construct in accordance with the specifications. Compact foundations to 95% relative compaction to a depth of 150 mm minimum. Replace unsuitable material as specified in 12.6.2 Excavation 12.8 INLET AND OUTLET CHANNELS WITNESS POINT Excavate the inlet and outlet of all culverts to facilitate the flow of water. Conform to the following: Bed width: Minimum 150 mm greater than overall width of culvert. Side batters: 45 degrees maximum to horizontal. Bed grade: 0.5% in the direction of flow for a minimum distance of 50 metres. Clean out new work and existing work affected by the new work. Witness point Advise superintendent within two days when clean out is completed.