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Technical Guide D4.24

ROTARING® Adjustable Levelling Rings reduce the risk of road and pavement

damage thanks to its patented, easily adjustable interlocking rising rings.

ROTARING® Adjustable Levelling Rings 500 Series

Product Attributes

Tapered, interlocking riser rings easily

adjustable to match the road level profile

Can be retrofitted to existing manholes

Various height options available

Reduces road damage and the long term

cost of pavement maintenance

Capable of infinite adjustment with

road camber

Applications

Stormwater and sewer manholes

in municipal, residential and

commercial applications

Quality

ISO 9001:2008 Quality

Management Standard

Standards

NZS 3101, NZS 3109

NZ Patent No. 590938

NZ Design Register No. 414550

Australian Patent No. 1569107

Developed in association with

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This patented design uses innovative interlocking technology to deliver perfectly aligned manhole covers that can be accurately adjusted to match the height and camber of the road surface.The existing method of manhole construction often leads to ongoing maintenance issues that result in a poor ride for motorists, noise and vibration complaints, and expensive repair costs. The tapered interlocking riser rings are used in pairs so that the manhole cover can be precisely adjusted to match the height and camber of the road surface. The bevelled adjustable rings incorporate a dovetail key to resist lateral shear and may be used with a cast iron manhole frame with a shear key skirt on the underside.

Product Attributes

■ Tapered, interlocking riser rings easily adjusted to match the road level profile.

■ Can be retrofitted to existing manholes.

■ Easy to assemble on site.

■ Various height options available.

■ Resists impact loadings during pavement construction and service.

■ Reduces road noise, vibration and complaints caused by loose manhole covers.

■ Reduces road damage and the long term cost of pavement maintenance.

■ Reinforced precast concrete components.

■ Capable of infinite adjustment with road camber.

Adjustable Levelling Ring Selection

Ø range = A–b+C

1. Measure depth from road surface to top of manhole chamber lid at the centre of the opening. (Fig. 1) Dimension A

2. From this measurement deduct depth of cast iron service cover frame (Fig. 1) Dimension b

3. From Table 1, select the top and bottom ring sections using this net depth measure

Example (Fig. 1):

■ Depth at manhole centre. A = 310 mm ■ Less depth of C.I. Frame. B = 95 mm ■ Plus depth of post construction surfacing as required. C = 0 mm ■ Nett Depth required is 215 mm ■ Select the ring combination from Table 1. In this example

LRA530.B1T2

Adjustment Set Screws

All Top ROTARING® Adjustment Levelling Rings are supplied standard with three only 12 x 25 mm set screws. If greater adjustment is required then you will need to source 40 mm or 60 mm long set screws separately.

Manhole Cover

Set Screw

Existing Road Level

New Road Level

A

C

B

Rotaring®

AdjustableLevelling Rings

Manhole

Chamber Lid

FIG. 1 ROTARING® Adjustable Levelling Rings installation profile.

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CI Manhole Lid

CI Frame

12mm Galv Set Screw

Top Ring

Base Ring

Manhole Chamber Lid

FIG. 2 Exploded view (N.T.S)

FIG. 3 Typical manhole cover faults

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TAbLe 1 ROTARING® Adjustment Levelling Ring Selection Table

Adjustment Range (mm)

Concrete Adjustment Rings Rotaring® Ø530 mm

Code

Bottom Top

B1 B2 T1 T2 T3

182–232 – – – b1 and T1 combination LRA530.b1T1

212–262 – – – b1 and T2 combination LRA530.b1T2

242–292 – – – b2 and T1 combination LRA530.b2T1

272–322 – – – b2 and T2 combination LRA530.b2T2

302–352 – – – b2 and T3 combination LRA530.b2T3

50

82

100 535 100

735

FIG. 4 base Ring Type b1

110 142

100 535 100

735

FIG. 5 base Ring Type b2

TAbLe 2 ROTARING® 500 Series Weight

Ring Type B1 B2 T1 T2 T3

Weight (kg) 38 64 48 60 72

base Ring Types

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132

100

100 535 100

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FIG. 6 Top Ring Type T1

162

130

100 535 100

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FIG. 7 Top Ring Type T2

192

160

100 535 100

735

FIG. 8 Top Ring Type T3

Top Ring Types

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TEMPORARY EXPANDABLEFLAT STEEL SHEET METALFORMER HELD IN POSITIONWITH TIMBER CROSS BRACES

ALLOWANCE FOR POST CONSTRUCTIONSURFACING THICKNESS AS REQUIRED

CONCRETEHAUNCHING

TOP RING

BOTTOM RING

USE HIGH STRENGTHEPOXY MORTAR WHENTHICKNESS < 12 mm

12 mm ØSET SCREW

BUTAL MASTIC SEALANT

DRILL AND INSERT 5 x 16 mmØ DEFORMED REINFORCINGBAR FOR RETROFITTING TO

EXISTING MANHOLES ORNON-REBATED CHAMBER LIDS

MANHOLECHAMBER LID

Installation

New Manhole

■ Install top and bottom adjustment ring assembly onto manhole chamber lid.

■ using a straight edge, align the plane of the top ring with the pavement surface by counter-rotating the adjustment levelling rings.

■ Insert set screws and place the cast iron service cover frame with interlocking skirt.

■ Make the final height adjustments using the set screws and ensuring the service cover frame exactly matches the profile of the road surface. When the service covers are being adjusted prior to resurfacing, for example allow an additional 10 mm for a seal coat and 40 mm for a new asphalt surface.

■ Place a chalk mark down the sides of the adjustment rings at one of the reference marks.

■ Temporarily dismantle the top ring and frame assembly.

■ Apply a bead of butyl Mastic Manhole Sealant, SM9020, to the face of the bottom ring spigot.

■ Place the top ring onto the bottom ring ensuring it is aligned with the chalked match marks.

■ Trowel on an initial layer of high strength concrete mortar on to the top ring.

■ Place service cover frame, and ensure the flange rests firmly on the set screws. The concrete mortar (SikaGrout 212) must fill the entire cavity between top ring and frame flange, and squeeze out between the two surfaces.

■ Re-check and ensure the frame is still aligned exactly, and matches the surface profile.

■ Trowel on the balance of the concrete haunching around the assembly and up to the finished surface.

■ Allow concrete to cure before trafficking

Retro-fit to existing Manhole

■ Ensure there is sufficient depth between the existing or new surface level and the top of the manhole chamber lid to accommodate the height of the new adjustment levelling ring assembly and service cover.

■ breakout and remove the old service cover and concrete down to the top of the manhole chamber lid.

■ Lightly scabble the concrete surface, broom and wash down to ensure a clean surface is achieved.

■ Install top and bottom adjustment ring assembly onto manhole chamber lid.

■ If a new rebated manhole chamber lid is not being installed, it is recommended that five 16 mm dia steel reinforcing starter rods are set into pre-drilled holes in the manhole chamber lid. The starter rods should be placed equally around the circumference, and set at least 50 mm from the face of the adjustment rings, and extend to the height of the top ring or 150 mm. Refer Fig. 9.

■ Complete installation as described above for a new manhole installation.

■ Where the existing cast iron frame is being used instead of a frame with the interlocking skirt, secure a flat steel sheet inside the frame to act as a former to hold the concrete haunching in place until set. Refer Fig. 9 10.

FIG. 9 Installation Detail: Skirted CI/DI frame

FIG. 10 Installation Detail: Flat bottom CI/DI frame Lid

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1 Cut out existing pavement in a 1040 x 1040 mm diamond shape with corners pointing with traffic flow.

3 Measure to ascertain depth to MH chamber lid

5 using straight edge rotate top ring positioning to line up with cross fall of pavement.

7 Install set screws to final measurement allowing for cover and frame and final pavement level.

2 Excavate to chamber lid

4 Place correct selected top and bottom ROTARING® Adjustment Levelling Ring set.

6 When correctly located mark ROTARING® Adjustment Levelling Ring for finished position.

8 Place frame and check cross fall levels (have allowed 12 mm in this case for future sealing).

Retro-fit to existing Manhole

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Disclaimer: While every effort has been made to ensure that the information in this document is correct and accurate, users of Hynds product or information within this document must make their own assessment of suitability for their particular application. Product dimensions are nominal only, and should be verified if critical to a particular installation. No warranty is either expressed, implied, or statutory made by Hynds unless expressly stated in any sale and purchase agreement entered into between Hynds and the user.

9 Install 5 x16 mm DIA Rebars.

11 Replace top ROTARING® Adjustment Levelling Ring and denso tape set screws. Trowel on an initial layer of SikaGrout 212.

13 Pour mixed concrete to encapsulate ROTARING® Adjustment Levelling Rings and cover assembly to finished level.

10 Remove top ROTARING® Adjustment Levelling Ring and place sealant.

12 Place cover and frame.

14 Concrete encapsulation completed.

15 Seams sealed prior to applying top seal. Note 15 mm allowance for seal.

16 Sealing completed.

Retro-fit to existing Manhole (continued)

Branches Nationwide Support Office & Technical Services 09 274 0316

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