CPO®

Stormwater Pit System

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PRODUCT BROCHURE

The Rocla CPO® Stormwater Pit system is designed specifically for stormwater applications.

It provides a simple, high quality and cost-effective alternative to traditional pit installations

CPO® Pits eliminate the need for preformed holes or knockouts, making pit alignment easier. The entry and exit holes are made on site, wherever and in whatever size required.

The modular system is available in a range of heights and standard diameters, with a complementary range of lids, covers and surrounds to complete the system. The pits are engineered from thin-wall, high strength concrete in accordance with AS4058-1992, providing known quality and strength.

ADVANTAGES• Assured quality

• Approved by Major Road

Authorities and Councils

• Cost savings

• No waiting for insitu concrete

to arrive

• No waiting for insitu concrete

to cure

• Large range of modular

components

• Fast installation

• Immediate backfilling

• No added labour costs

• Pipe and pits ordered

together

• Pipes enter the pit radially

• Simple orientation and

installation

• Holes punched quickly, where

required, compared to square

and rectangular pits

Heavy Duty Medium Duty Light Duty

Shafts / Bases 210kN 210kN 210kN

Lids / Covers / Surrounds 210kN 150kN 80kN

ENGINEERED DESIGN Rocla CPO® Pits allow for non-uniform backfill and compaction during construction. The pit walls are designed for differential pressure caused by a 1-metre variation in depth of backfill on opposite sides of the shaft, plus a live load allowance equivalent to 1 metre of fill, as well as a factored vertical load of 210kN

CPO® precast base slabs are designed for a factored live load of 21OkN from AS2996-1992. The precast base slabs and shaft segments are designed for a maximum depth of 1Om.

Design for durability is based on a minimum exposure classification B1 as defined in AS3600-2009 section 4. B2 exposure classification is available on request. Shaft segments are based on AS/NZS4058-2007 for “normal” environments

A FAST, LOW COST PIT CONSTRUCTION

COMPONENT LOAD CAPACITIES

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EASY TO ASSEMBLE MODULAR COMPONENTSSHAFTSRocla CPO® Pit sections are manufactured in most states in nominal diameters of 600, 750, 900, 1050 and 1200mm. Other sizes from 1500mm to 3000mm diameter are available at some sites. Shafts are available in standard heights of 300mm to 1200mm. Check with your local Rocla sales office for range details.

PRECAST BASESPrecast bases provide major time savings. The bases slab is simply lowered into the excavation and placed using a single survey reference point. The profiled joint rebate on the base positively locates the shaft, speeding up installation of the complete system. Bases are suitable for pits up to 10 metres. For deeper pits, special base slabs can be provided.

COVERS AND INLETSRocla CPO® Pits can be supplied with a range of lids, covers, surrounds and metal grates. A wide range of inlets are also avaliable for junction and surcharge pits, side entry and kerb inlet pits etc, allowing a complete system to be tailored to local construction and design standards.

JOINTSAll components are provided with a joint rebate. The “step” profile of the joint provides a flush internal finish that inhibits ingress of soil without the need for sealing. The robust design of the rebate also minimises the chance of damage to the joint profile during on-site handling.

STEP IRONSPlastic-encapsulated step irons are avaliable to access deeper pits. The step irons are spaced at nominal 300mm centres on CPO® Pits with diameters from 900mm to 1200mm.

CPO® pits with 900 and 1200 diameter are all fitted with ferrules for step irons as standard. The choice of steps or no steps is made on site simply knocking step irons in the ferrules if steps required due to depth of pit. CPO® Shafts are provided with lift holes. Lift shafts using appropriate load rated slings, certified lifting device or bar, certified lifting pins. .

QUALITYAll products are manufactured under the Rocla Quality Management System. This system is based on compliance with the requirements of AS/NZS ISO9001 : 2000. In accordance with Rocla policy, quality system documents and production records are available for audit by customers at our work.

INSTALLATION GUIDERocla CPO® Pits can be installed quickly and easily by pipe laying crews while the pipe is being laid, using normal pipe-laying plant.

LIFTING All components should be lifted using the cast-in lifting attachments or lifting holes provided.

PUNCHING OUT THE HOLE Hole forming is fast, easy and ensures accuracy of positioning of holes. Hole accomodation table illustrates the maximum size and number of holes permitted for each diameter.

Mark the position of the inlet and outlet pipes on the CPO® Pit shaft by rotating a string and crayon around the pipe centre. Allow for a 25mm gap around the pipe and remember to take into account the curvature of the wall.

The hole can be made using a 3kg sledgehammer, starting at the centre. At about 75mm from the marked line, a 1.5kg hammer should be used for better control of the finished dimensions. A small amount of over-break is of no consequence. Alternatively, cut the opening with an abrasive disk in a series of straight lines or chords around the marked line.

When all holes have been punched out, cut away the exposed reinforcement with bolt cutters and trim back to minimum projection. Coat broken surfaces with an approved sealant or epoxy.

PREPERATION OF THE BASE The pit area should be excavated to a suitable width to provide side clearance and to correct depth for the base. The precast base should be supported on a minimum 75mm layer of compacted bedding sand of fine granular material.

If constructing as in situ base, place the shaft with hole punched out first then form the base in accordance with the details specified on the designer’s drawings.

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SAFETY Safety helmets, safety boots and safety galsses should be worn at all times when punching out the hole and when handling and installing precast sections.

KEY INSTALLATION POINTSAll work should be conducted from outside the pit.

• Cut the reinforcement only when all holes are punched.• Punch the smallest possible hole (recommended hole diameter pipe OD

plus 50mm).• Holes should be separated by a minimum space of 200mm.• At least 40% of the pit wall should remain in horizontal plane• The starter shaft should be high enough to take the biggest pipes.• Ensure holes do not interfere with step irons.• Check step irons are in correct alignment• If a 450mm high shaft is used, it must be placed last to maintain step

spacing.• With square surrounds, ensure that backfill is placed to the full height

and properly compacted under corners to square and rectangular pits

Pit Diameter (mm) Pipe Diameter (mm)

A B C

600 375 - 375

300 225 375

750450 - 450

300 225 450

900

600 - 600

450 225 600

450 375 450

1050

750 - 750

600 225 750

600 450 600

1200

900 - 900

750 300 900

750 450 750

NOTE: Pipe B may be increased by one size of all angles between pipe centrelines exceed 100 degrees. Accomodation limit for larger sizes are

available upon request.

PIT INSTALLATIONWhen the precast base has been replaced and its position and level checked, the shaft can be lowered into position and fitted on to the end of the entry pipe.

The shaft will be positively located on the base by the matching joint profiles. The procedure is the same when there are multiple pipes entering the pit. Further shaft sections can be placed in any order to bring the pit to its designed level. The joint profiles will positively locate each section.

Note that a 450mm high shaft with a step iron must be placed at the top of the pit structure to maintain step spacing. Final small adjustments to the finished level can be made by either mortar packing or cutting off part of the shaft top with an abrasive disk. Placement of the surround completes the main body of the pit.

The exit pipe may now be laid away from the pit. The annular space between the pipe and the shaft should be cleaned of dust and loose material before packing the gap with mortar. The mortar should be placed into the prepared area, working to the full depth of the pit wall. The mortar should we worked in firmly to ensure a good bond.

BACKFILLING Place fill material carefully around the base and shaft units and compact, ensuring the base and shafts are not disturbed. Continue backfilling and compacting, using even layers of fill material. When pits are installed in pavements or roads, instructions from the road or supervising authority must be strictly followed.

CONCRETE PRODUCTS | PIPE | ENGINEERING CAPABILITY

For more information call Rocla on 131 004 or visit rocla.com.au

The information contained within this brochure is intended as a guide for information only and is subject to change without notice. Rocla does not invite any person to act or rely upon such information.

Before application in a particular situation, Rocla recommends that you obtain appropriate independent qualified expert advice confirming the suitability of product(s) and information in question for the application proposed.

To the extent permitted by law, Rocla disclaims all liability (including liability for negligence) for all loss and damage resulting from the direct or indirect use, or reliance on, the information provided in this brochure.

® and TM are trademarks of Rocla Pty Limited ABN 31 000 032 191

© Rocla Pty Limited, May 2018. All rights reserved.