Hollowcore Plant Design Manual

S P I R O L L H O L L O W C O R E P L A N T D E S I G N

SPIROLL PRECAST SERVICES LTD.

MANUAL FOR THE DESIGN OF A SPIROLL HOLLOWCORE PLANT

Spiroll Precast Services Ltd. Unit 2 Kingsway Industrial Park

Derby, DE22 3FP

United Kingdom

Tel: +44 (0)1332 365 131 Fax: +44 (0)1332 291 736

Web: www.spiroll.co.uk Email: [email protected]


Abstract This document is designed to provide guidance and outline the main considerations in the initial planning of a

Spiroll Hollowcore plant. The information presented is based on 40 years of Spiroll experience.

To summarise the key points: -

- The Plant must be planned with both the short term and long term annual square metres of

hollowcore slabs based on beds numbers and length. The normal bed length can vary from 60 to 150

metres Spiroll would recommend a length of 120 metres.

- The Production Schedule must allow sufficient time for adequate curing of the hollowcore slabs

before the tension in the strand is released and slabs are cut and removed to allow daily turn round of

the beds.

- The Factory Layout should include provision for immediate and future expansion of more

Production Beds so that the production can grow to meet market demand.

- With a low cost start-up and access to one side of the beds, initially handling of product can be with a 5

tonne forklift. This system can be replaced by a gantry cranes, overhead cranes or travel lifts in the

future. Normal crane capacity would be 5 to 7.1/2 tonne.

- Similarly for the first two beds installed concrete delivery can be by skip and forklift from a batching plant

or ready mix truck. This can be replaced by crane and skip or gantry/bullet skip distribution as

appropriate as the production volumes increase.


Table of Contents

The Spiroll Hollowcore System 4 The Spiroll Extrusion Process 5

Spiroll Hollowcore Slabs 7 Speed 7

Features of the Slab: - 8 Tests and Approvals 10

Spiroll Load Table 11 TermoDeck 13

Spiroll Factory Design (Typical Start-up) 15

Scope of Plant Layout 15 Site Construction 16 Service Requirements 16 Production Beds 17

Basic Bed Requirements 18 Spiroll Bed Design 18

Abutments 19 Fixed Steel Posts 19 Hydraulic Detensioning System20 Multi-Stressing System 21

Drainage 21 Commissioning 21

Production Processes 22 Batching/Mixing 22

Aggregate Bunker & Weighing Belt Conveyor 22 Skip Hoist & Bucket Feeding 23 Main Chassis Superstructure 23 Single Shaft Axial Mixer 25 Basic Automation System 25 Computerised Command & Control System (SCADA) 26 CEMENT SILO 26 EQUIPMENTS OF CEMENT SILO 26 SILO-TOP FILTER 27

CEMENT SCREW CONVEYOR 27 Concrete Mix Design 27

Material Recommendations 27 Mix Proportion 28

Concrete Distribution 29 Gantry Crane 31 Overhead Crane 31 Forklift Truck 32 Readymix Truck 32 Concrete Distribution System 33

Curing 36 Cutting the Slabs 37 Basic 90o Crosscuts 38 Basic Long/Rip Cuts 39 Multi-Angle Cuts 40 Secondary Cutting Station 42

Lifting & Transporting the Slabs 43 Lifting (Stripping) Clamps 43 Transporting Slabs to the Stock Yard 44

Preparing the Beds 44 Prestressing & Equipment 46

Strand Dispensers 46 Stressing Equipment 47 Stressing Pump 48 Stressing Jack 48 Stressing Grips 49 Digiforce Tension Meter 50

Fixing the Slabs 52 SlabLock Clamps 52 Fall Arrest Clamps 53 Edge Protection 54

Hollowcore Production Software 56


4

The Spiroll Hollowcore System The Spiroll Production System is an internationally proven, cost effective, economical method for the

production of Precast Hollowcore Concrete Slabs.

Spiroll Hollowcore Slabs have good unsupported span characteristics with excellent load carrying

capacities and are used extensively for floors, roofs and walls in both commercial and, residential building

projects.

The Spiroll Corporation Ltd. originally developed the technology in Canada

in the 1960s and pioneered the production of hollowcore slabs using

long-line extrusion & high frequency vibration technology.

The original Spiroll Producers founded the International Spiroll

Producers Association (ISPA) in 1969, which has since 1993 been

known as the International Prestressed Hollowcore Association

(IPHA) www.iphaweb.org.

There are currently in excess of 40 Spiroll Production Plants operating in over 20 Countries throughout the

world.


5

The Spiroll Extrusion Process

The Spiroll Extruder is the heart of the production system. It was the Worlds first machine for producing

hollowcore slabs that did not require a separate driving force to move the machine along the Production

Bed. The same effort that feeds the concrete mix through the machine and forms it into the final precast

slab also provides the motivation to drive the extruder along the bed. This natural process propels the

Extruder along the Production Bed & allows the compacted concrete to reach the required density.

Due to the intense vibrations and pressure within the machine the concrete mix is

'plasticised' during the short time that it is passed through the Extruder which

allows it to be moulded and formed into the required section.

The formed slab then reverts to its 'dry' state and reaches such a high density that

it is possible to stand on the slab immediately after the extrusion process. After a


6

period of natural or accelerated curing, the slabs are then cut to length, stripped from the casting bed and

transported to the storage area.

The casting beds are then cleaned, a release agent is applied and high tensile steel strands are located in

position for the automatic extrusion process to begin again. Normally the entire production takes place

over a 24-hour cycle.

Spiroll Extruders are by far the simplest hollowcore machine on the market in terms of their design & ease

of use. Once the machine has been commissioned & set-up to suit the Production Bed, it simply requires

the required mix to be put in the hopper and the machine to be started. There is no need to play around

with the concrete mix or adjust the Extruder once it starts running. The extruder only requires one man to

operate and is extremely easy to maintain. It is profitable because of the simplicity and reliability of the

overall design.

Spiroll Extruders are capable of producing hollow core slabs from depths of 150mm-470mm with widths

from 600mm-1800mm.


7

Spiroll Hollowcore Slabs In terms of selling the Spiroll Hollowcore Slabs into your local market you will see that the slab is such a

versatile precast element that it can be utilised in a wide range of applications and thus expand the

available markets.

Few building materials available today offer the economy, flexibility and reliability of precast prestressed

concrete. The scope of applications is exceptional: -

Durability

Spiroll hollowcore slabs provide long-term performance in extremely harsh conditions that could destroy

lesser materials. It is extremely resilient to deterioration from the weather and the denser the slab the

higher the fire rating.

Speed

Hollowcore allows you the producer to have full control

over all the variables, which affect the durability, strength

and appearance of the slab.

The high quality and excellent finishes of the slabs reduce

site work to an absolute minimum.


8

Flexibility

Spiroll hollowcore slabs are not only a versatile flooring &

roofing application but when used in conjunction with the

Spiroll Topping Machine can also utilised for wall panels.

The Topping Machine is used to give special decorative

finishes to the hollowcore by using different aggregates

and colours on the soffits and tops of the slabs.

Economical

Spiroll hollow core slabs themselves are up to 30% lighter than the equivalent in-situ floor. Building

foundations can therefore be lighter as they are required to support less weight. Any supporting columns

and beams can also be significantly reduced. Longer spans and greater loads can also be utilised from the

Spiroll slabs.

Features of the Slab: -

- Eye pleasing top and bottom surfaces.

- Fire resistance (2-4 hours fire rating) depending on design

- High density product

- No strand slippage

- Low cement content

- Greater span/depth characteristics

- Consistent camber

- Greater span load characteristic

- Close dimensional tolerances

- Eliminates costly shoring during installation

- All weather construction

- Immediate working surface

- Custom cut length to suit needs

- Excellent sound barrier (due to hollows).


9

- Carpet direct top surface

- Speedy erection, reducing interim financing

- Maintenance free

- Economical long line Production

- Unlimited design possibilities, compatible with almost all building materials

- Recommended for best use with TermoDeck heating & ventilation system

- Flexibility in design & application

There are a variety of uses for hollowcore with applications for floors, roofs and wall panels being the

most common. However, some of Spiroll's more innovative producers have found use for hollowcore in

such projects as parking decks, bridge deck (permanent forms), basement walls, retaining walls,

pedestrian bridges and parapet wall (air displacement).


10

Tests and Approvals

Spiroll Hollowcore Slabs have World-Wide recognition & acceptance as a building element. Tests and

approvals are compiled in what now is Spiroll's Seven Volume Technical Manuals. Additional tests, which

have been done are as follows: -

- Report on Structural Test on Spiroll Extruded Hollow Core Slabs, Report K68-05 Stockholm,

Sweden, August 1968.

- Report on Test to Demonstrate the Adequacy of Floor or Roof Assemblies using Spiroll Panels

(By: S.B. Barnes and Associates).

Load Tables are available for the following depths of Spiroll Slabs: -

- 15x120cm Hollowcore (No Topping)






A comprehensive range of selections allows versatility and economy of materials by selecting the most suitable

slab for the load/span required. The table below gives a visual indication of which depth of slab to choose when

comparing the Live Loads (kN) against the Clear Span (m).


11

Spiroll Load Table

LIVE LOADS (kN)

CLEAR SPAN (M) 3.0 4.0 4.5 6.5 9.0 11.5 16.5

0.0 - 3.0

15cm

3.0 - 3.5

3.5 - 4.0

4.0 - 4.5

4.5 - 5.0

5.0 - 5.5

5.5 - 6.0

6.0 -.6.5

20cm

6.5 - 7.0

7.0 - 7.5

7.5 - 8.0

25cm

8.0 - 8.5

8.5 - 9.0

9.0 - 9.5

9.5 - 10.0

10.0 - 10.5 30/

32cm

10.5 - 11.0

11.0 - 11.5

11.5 - 12.0

40cm

12.0 - 12.5

12.5 - 13.0 --

13.0 - 13.5 --

13.5 - 14.0 -- --

14.0 - 14.5

47cm

-- --

14.5 - 15.0 -- --

15.0 - 15.5 -- -- --

15.5 - 16.0 -- -- --

16.0 - 16.5 -- -- --

16.5 - 17.0 -- -- --

17.0 - 17.5 -- -- -- --

17.5 - 18.0 -- -- -- -- --


12

The Spiroll Load Tables show: -

- Physical dimensions of the Spiroll hollowcore slab sections.

- Strategic location (arrangement) of prestressing strands.

- Yield (ultimate strength) of prestressing steel.

- Superimposed load capacities for a given number of strand and span.

- Governing design criteria for concrete strength and deflection 1imitations.

The concrete strength at 28 days is conservatively designated at 35 N/mm however, concrete strengths

of as high as f'c = 60 N/mm have been readily obtained by most Spiroll producers after the fairly dry

concrete has been extruded by the Spiroll Extruder.


13

TermoDeck

The TermoDeck System is a fan-assisted, heating/cooling

& ventilation system that uses the high thermal mass of

hollow core slabs through which warmed or cooled air is

distributed.

The mass of the building, built using hollowcore, is used as

an energy store which creates an overall effect that damps

down fluctuations in temperature, resulting in reduced

energy needs for heating or cooling the air and for moving it

round the building.

The supply air passes through the cores at low velocities, allowing prolonged contact between the air and

the slabs. This enables the slabs to behave as passive heat exchange elements that release heat to, or

absorb heat from, the air in the slabs.

If a building is well insulated, air tight and has heat recovery, the utilisation of the thermal mass of the

TermoDeck in combination, will produce a very efficient environmental control solution. As a result, a


14

building's requirements for heating and cooling systems, and related equipment will be less, and costs

significantly reduced.

A report on the Elizabeth Fry Building built using Spiroll Hollowcore Slabs and

TermoDeck (New Practice Final Report 106, 1998) by the UK Government's

Department of the Environment summarises its conclusions as follows: -

"Energy consumption is half that of a conventional building of this type. Use of the

building's thermal mass provides good levels of comfort. Occupant satisfaction

and productivity are high. Capital and maintenance costs are low".

TermoDeck is a proven and reliable system which has been installed over the last 25 years in more than

360 projects all over Europe and the Middle East. For further information on the TermoDeck system

please visit their website on www.termodeck.com.


15

Spiroll Factory Design (Typical Start-up)

Scope of Plant Layout

The basis of the proposed production facility shall be two (2) 120 meters long Production Beds and 1.2

metres wide. This will provide an approximate output of 65,000m of slabs per annum based on an

average of two hundred fifty (250) working days per year.

Provision shall be made for future expansion of an additional two (2) identical Beds. The system will

include two (2) Extruders; one (1) Saw and one (1) Pallet Cleaning Buggy.

This should be considered with a view to the future requirement for increased numbers of beds, the

handling of the product, the distribution of the concrete, the maintenance of the machines, drainage,

access, wiring of the beds and storage of the product.

There are advantages to site the mixer in the middle of the factory to minimize the travel time for the

concrete. Most factories however have end batching and have the appropriate size and speed of crane etc

for distribution of concrete.


16

With an overhead crane the opportunity exists to extend the crane long travel beyond production

buildings. This enables it to be used for transfer of product to the yard and some for yard functions in the

future.

A Batching Plant providing for handling of two (2) aggregates and silo storage of cement, shall deliver

appropriate volumes of concrete to delivery buckets.

Transport of the Concrete Delivery Skip/Buckets to the Extruder shall be accomplished by Forklift Truck(s),

Overhead Cranes or other suitable methods.

Site Construction

Stressing Abutments and Production Bed foundations to be designed as per details provided by Spiroll

Precast Services Ltd and Soil Investigation Report provided by the customer.

Foundations for Batch Plant, electrical and mechanical distribution centre and cement silos.

Roofed, insulated structure to cover production area.

Fully enclosed areas for parts storage and maintenance.

Service Requirements

- Water Pressure 3.5 kg/cm

- Electrical power Industrial Input 3 phase 115 or 220 volt.

- Covered Production Area 3,168m2

- Stone and Sand Area 510m2

- Batching Area 135m2

- Stressing Cables Storage 432m2

- Maintenance Area 44m2


17

- Parts Inventory Area 50m2

Production Beds

The bed length is dictated by a number of factors, some of which have associated advantages and

disadvantages. These factors could be available space, production capacity, flexibility of production

volumes, strand patterns, bed utilisation, turn round time & off-cuts wastage.

Shorter Production Beds give easier coverage for curing, delivery and transport. They are more flexible for

scheduling of multiple machine sizes, but are not so productive. We would normally recommend a bed

length of 120 metres.

Water consumption for the casting (pallet water) is estimated to be between 250 and 500 litres per 100

square metres of bed.


18

Basic Bed Requirements

The following factors should be considered when constructing a bed for casting hollowcore: -

1. Rigidity The plate thickness and the longitudinal/transverse support must be adequate to

prevent deformation of the casting surface by the weight and pressure of concrete.

2. Dimensional tolerance To ensure that the strand is correctly position for consistent cover,

and that beds are not damaged during sawing, a straight line tolerance on the beds of 2mm

should be maintained over the bed length.

3. Plate quality Good quality clean rolled plate must be selected to ensure a clean casting

surface with no curled ends.

4. Anchorage and weight To reduce transmission of vibration to the extruded product.

5. Longitudinal movement To allow expansion and contraction of the steel bed with changes in

temperature.

6. Foundation design To suit local ground conditions.

7. Support and Fastening Methods To prevent longitudinal or vertical misalignment.

8. Pallet spacing - 2 metres is recommended although spacing can be down to 1.6 metres.

Construction techniques vary, but generally heavier construction gives more dimensional stability and

longer life.

Spiroll Bed Design

Spiroll Casting Beds are supplied in prefabricated in 10 meter sections. Each section contains Two Side

Member Channels running the complete length of the section and has Steel Cross Member Supports at

approximately 600mm intervals. A 8mm thick skin plate is welded to the Channels and in turn Chamfer

Rails welded to the skin plate. The surface of the skin plate will be grinded to the iron brightness.

Provision is made for six number 1 OD holes to allow for under bed heating pipes which creates an

independent radiator of each section to speed up the curing cycle. The inlet and outlet are connected to

a main supply and return that runs the full length of the bed.


19

The sections are also supplied with Ground Fixing Plates and Resin Anchor Bolts supplied for fixing the

sections to the Concrete Base.

The assembly would consist of providing a concrete base for the bed. The 10m Sections are welded

together (after connecting the heating pipes together on site). Holes for fixing need to be drilled into the

ground and the Sections are secured with the Resin Anchor Bolts. After the installation the welds would

need to be grinded on each section and the Bolts can be screed over.

To reduce heat loss insulation sheets should be installed under the beds. Typically these would be

50/60mm foil backed sheets held in place by pressed metal angles or straps. On site the bed is filled with

concrete and covered with the layer of insulation, before turning and connecting together. If the beds are

filled with concrete prior to installation, the cross bars can be used to support the heating pipes and their

centres increased to 1 metre. If not filled the cross supports are drilled to support the heating pipes and

installed at 400mm centres.

Abutments

The capacity of the abutment design should take account of future requirements for deeper hollowcore

slabs as a small additional cost at the installation stage will save significant costs later (The stressing load

for a 400mm deep unit could be as high as 300 tonnes)

When preparing the ground works for the abutments provision should be made for future beds to

minimise costs.

Fixed Steel Posts

The simplest & cheapest method is have fixed steel posts at both ends of the production bed. With this

method the strands are tensioned individually using a hydraulic Pump Unit & Stressing Jack.

However extra due care needs to be taken when cutting the strand or shock-detensioning to avoid

cracking & damaging the slabs. This can be done by releasing the tension at the edges first, preferable

with oxyacetylene torch. By pre-heating the strand with the torch before cutting the shock to the concrete

is reduced.


20

Hydraulic Detensioning System

To get round the problem of Shock Detensioning Spiroll have developed a simple & cost effective

Hydraulic Detensioning System.

The design of the abutment is based on two posts, which are cast on site into the concrete at an angle;

this allows the highest point of the assembly to be below the level of the beds. The Stress is transferred to

the posts by a yoke, which fits over the posts and is locked off, to allow the Hydraulic Detensioning

Assembly to be fitted & removed.

The beams for the yokes must be adequate for the bending moment and flexural strength. The cross

section of the welds must be adequate for the stressing loads. The welding is critical. A complete

assembly would include the posts, yoke and lock-off assembly. One assembly would be required for each

bed.

The design of the Hydraulic Assembly is based on releasing the lock-off and controlling the Detensioning

with hydraulic relief valves. The Cylinders are extended using a two-stage hand pump to maintain equal

displacement.

They have a 150 Ton Max Capacity. The Release Extension is 35mm. They also come complete with hoses

and a lifting point.


21

Multi-Stressing System

Hydraulic Multi-Stressing is the most efficient and safest system. This method allows all the Strands to be

both stressed and detensioning all in one go.

Multi-Stressing significantly reduces the time it takes to stress with a Pump & Jack and eliminates the

possibility of bond slip or damage to the slabs caused by Shock Detensioning.

Drainage

Control of the water used during sawing, and maintaining a uniform level of water on the bed ahead of

the casting machine can be achieved more easily if the beds are installed with a fall of approximately 3 to

4mm per metre of bed run, over the length of the beds.

This will assist to maintain a uniform soffit finishes to the product and a clean well drained factory. Slurry

and waste material will be cleaned towards the wet which is normally also the mixer and wash down

end. The water should have free fall to a shallow catchments, which can be used to drain off excess water

and be cleared with a front loader.

Commissioning

Upon completion, by the owner, of all site preparations, foundations, building, provision of essential

services and compliance by owner with contract. Spiroll will provide sufficient technicians to install all

Machinery supplied by Spiroll.

Spiroll personnel will then proceed to commission the Spiroll equipment by demonstrating through a

complete production cycle, that all systems are operating satisfactorily.


22

Production Processes

Batching/Mixing

Aggregate Bunker & Weighing Belt Conveyor

Aggregate Bunker: 1 unit

Volume : 45 m3

Number of Aggregate Parts: 3x15 m3

Discharge valves: 2 units / part

Pneumatic Piston: 6 units, PEMAKS

FRY Air Preparation Unit : 1 unit, REXROTH

Sand Vibrator: 2 unit, MVE 200/3,WAM

Aggregate bunker is designed and manufactured as per related DIN norms to operate under heavy

working conditions for long time. There exist 2 electro-pneumatically controlled discharge gates, which

provide easiness and choice in the discharge together with suitable elevation.


23

Weighing Belt Conveyor: 1 unit

Load Cell: 4 x 2000 kg

Dimensions: 1 unit, 800 x 9850 mm.

Rubber belt: DERBY

Bearings: SNA series with lubrication greaser

Drums: Driving drum covered with10 mm rubber

Weighing bunker vibrators: 1 unit, MVE 200/3,WAM

Motor Gear Box: 7,5 kW,1500 rpm,i=12,GAMAK-DISSAN

Aggregate weighing belt conveyor, which has weighing capacity of net 3 tons (net 1,8 m3) with 2,5%

sensitivity, manufactured to operate without any problem under heavy working conditions with mechanical

separator, every kind of safety precautions, air pressure measuring device and etc. as per world

conditions. Aggregate is weighed by 4 units of load cells and weighing belt conveyor has all safety

switches like; rope controlled safety switch, emergency stop button.

Skip Hoist & Bucket Feeding

Dry filling capacity: 750 lt.

Max. filling weight: 1100 kg

Motor: 7,5 kW, 1500 d/d , GAMAK

Speed of hoist up/down: 0,4 m/s

Main Chassis Superstructure

Plant chassis, which provides 4250 mm useful height, is produced from section - profile and sheet iron,

according to ISO9001 and all related DIN norms.

Below listed cement weighing and water weighing hoppers are mounted on a separate removable chassis

placed on the mixer chassis and equipment with ladder platform and parapets.

- Cement Weighing Hopper: 1 unit


24

- Weighing Capacity: 300 kg

- Load Cell: 2 x 1000 kg

- Pneumatic Valves: V1-FS200S,WAM

Diameter 200 mm

- Driver: CP 101,WAM

- Vibrator : 1 unit, MVE60/3,WAM

- Water Weighing Hopper: 1 unit

- Weighing Capacity: 120 kg

- Load Cell: 1 x 1000 kg , ESIT

- Pneumatic Valve: V1-FS150T, WAM

- Driver: CP 101, WAM

- Additive System: 1 unit

- Capacity: 20 kg

- Load Cell: 100 kg,EST

- Pneumatic Valve: 1, Valbia

- Pneumatic Equipment: 1 Set

- Compressor: TAMSAN

1100 lt/min volumetric flow rate

5,5 kW motor power

550 lt depot volume

7,5 kg/cm2 operating pressure

Pipe and fittings materials

Water equipment

Piping installation on the plant

1 pneumatic valve, Valbia


25

Note: Pressure tank and water piping installation up to the plant main chassis shall be maintained by the

customer.

Single Shaft Axial Mixer

- Type: MK 750/500

- Mixer Capacity: 0.5 m3

- Feeding Capacity: 750 lt.

- Fresh Concrete Capacity : 625 lt.

- Compacted Concrete Capacity: 500 lt.

- Motor-Reduction Gear Box Power: 18,5 kW , GAMAK - YILMAZ

- Mixer Body & Side Body Inner Linings: ST52-3 10 mm

- Linings of mixing arms: Ni-hard 20 mm

- Water distributor

- Pneumatic discharge door

- Manual central lubrication system

Singe shaft mixers are easy to operate and long life mixers with very strong spiral shaped mixing arms,

compact structure and provide fast mixing, practical loading.

Basic Automation System

- Command and control operations are done by PLC. At the maximum capacity high weighing

and dosage sensitivity can be achieved by advanced PLC programs and error control

algorithms.

- Visualization and Control based on C7-635 system with integrated CPU S7-314C-2DP PLC,

SIMATIC HMI Panels.

- SIEMENS Electrical Installation devices and sensors. Remote stations with distributed I/O

stations.

- Real time simulation for operator training fast and safely without any lost material.


26

- Increasing the production capacity and quality and more quality by using SIEMENS technology

and professional algorithms.

- All kinds of parameter setup, receipt and calibration operations can be done on operators

panel screen; process, production and failure information can be taken.

- Manuel and automatic operation can be done on illuminated mimic diagram. Voltage and

current values can be followed by digital indicators on the panel.

- MCC and command panel is manufactured up to heavy operating conditions and has all kinds

of electrical protection.

Computerised Command & Control System (SCADA)

- All command and control operations, all kind of reporting, failure indications and etc are done

by PC Monitor and animation support with PC, printer, UPS and SCADA software.

- Desired amount of receipt can be prepared, customer and truck information can be entered

and production information of at least past-one year can be shown.

- All command and control operations, all kind of reporting, failure indications and etc are done

by PC and animation support with SIMATIC WinCC Flexible RT software.

- Remote maintenance and servicing via Internet/intranet.

CEMENT SILO

- Capacity: 50 ton / unit

- Plate thickness: 5 6 mm

- Filling pipe : 4 inches

- Ladder, manhole, platform, and parapets are included.

EQUIPMENTS OF CEMENT SILO

- Silo pressure safety valve: WAM

- Level indicators: ILTC220,WAM (top and bottom)

- Fluidisation nozzle : 6 units/Silo WAM

- Mechanical valve: V2FS250S,WAM


27

- FR Filter regulator

- 220 volt, solenoid valve

- Pneumatic pipe installation

SILO-TOP FILTER

- Filter: 24 m2 JetPulse,WAM

- Surface area: 24,5 m2

- The number of filter cartridges: 7 units

Air filtration flow of 2200-2500 Nm3/hr.

- Filter has diameter of 800 mm, body made from 1 mm AISI304 material, cleaning system

Jet Pulse, electronically control.

CEMENT SCREW CONVEYOR

- Dimension: 193x7500mm,WAM (Universal Inlet)

- Motor Power: 7,5 Kw

- Capacity: 40 tons/hour

Concrete Mix Design

The Spiroll system uses an extremely dry concrete mix, typically a water/cement ratio of approximately of 0.20

to 0.30 (it may be necessary to allow approx. 0.05 additional for aggregate absorption).

The mix design will depend on the availability of local cement and aggregates and can be easily fined tuned to

suit local conditions. To reduce curing times and to allow double casting within a 24-hour period the cement

proportions can be increased.

A survey of customers suggests that the proportion of course to fine aggregates does vary to suit local

conditions.

Material Recommendations


28

Course Aggregates

10mm/14mm Aggregates (Max. Size 16mm for mechanical clearance).

Irregular shape is recommended. Extremes of very rounded or extremely angular respective are prone to

sagging and lower speeds or are difficult to compact.

Sand

Clean Zone 2 or equivalent.

Cement

Cement can be normal Portland cement or High Early strength cement as the contribute to workability and

benefit to rapid curing.

Water

This could range from 23 to 70 litres per cubic meter of mix depending on the moisture content and/or

degree of absorption of the aggregates.

Admix

Admixtures may be useful for workability or set control, but are not normally required.

Mix Proportion

The table below lists different Aggregate Types versus different Average Cement Contents & Proportions.

Type III With Type I With

(High Early) Additive (Normal) Additive


29

Normal Weight - "Average" Hardness (e.g. normal limestone)

Sand 44% 52% 44% 48%

Stone 40% 33% 36% 35%

Cement 16% 15% 20% 17%

Normal Weight - "Hard" (e.g. granitic)

Sand 44% 43% 38%

Stone 39% 41% 45% Nil

Cement 17% 16% 17%

Slag

Sand 46%

Stone 38% Nil Nil Nil

Cement 16%

Expanded Clay/Shale

Sand 53% 55%

Clay/Shale 20% Nil Nil 22%

Cement 27% 23%

Concrete Distribution

While the Extruder is the heart of the Spiroll Hollowcore System, additional equipment is essential to

transport the concrete mix from the batching plant to the Extruder.

Delivery of the concrete must be carefully thought out so that the Extruder doesn't run out of mix and slow

down production. Several methods of concrete delivery can be used such as overhead cranes, fork lifts and also

more automated Concrete Distribution Systems (CDS).


30

To maintain continuity of supply of concrete to a Spiroll Extruder producing (as an example) a 200mm deep slab

would require 1m every 6/7 minutes.

The Extruder can be stopped between loads but it is preferable to maintain the continuity of the casting once

the line has been started. The permissible standing time before the machine has to be lifted clear of the curing

concrete would be established by trials but would not normally be between 5 and 10 minutes.

When delivering concrete the transfer between skips should be kept to a minimum to avoid segregation. The

skip should be bottom opening with a wide mouth (1m) to avoid trapping and segregation of the stone from

the fines.

Using an average extrusion speed of 1.2m/min and a Bed length of 120 metres, the casting time per bed would

be around 100 minutes. Transfer for lifting of the Extruder, setting-up, cleaning time etc. would add

approximately 15 minutes.

Consideration should be given to the systems available to distribute the concrete as follows.

METHOD BENEFITS DISADVANTAGES

Forklift Low initial cost

Readily available Floor space required

Gantry Crane Reduced floor space

Danger of Legs

Overhead Crane Clear of floor space Part of building

Cost of structural supports

CDS System Automation Cost of Investment


31

Gantry Crane

Overhead Crane


32

Forklift Truck

Readymix Truck


33

Concrete Distribution System

The CDS is a smart crane concept, which was designed 10 years ago. It is a modular design based on

standard crane components that allows great freedom in lifting capacities and speeds. This System uses a

self-propelled Skip to receive concrete from the batching plant and deliver it into the Extruder hopper.

Operation: -

1. The CDS is operated by a touch screen, which is mounted at ground level. The operator selects

the type of hollowcore that is to be produced.

2. The operator switches to auto mode (on the radio remote unit) and the crane will automatically

lift the skip and travel towards the filling station.

3. The hoisting unit automatically lowers the skip into the filling station and waits for the signal that

skip has been filled.

4. After the signal the skip will be automatically lifted and the crane and crab move toward the

Extruder.

5. As the crane and crab reach the Extruder the skip will automatically lower to the required level.

6. The operator must switch to manual operation and fill the casting machine by the remote control.

7. After the skip has been emptied the operator starts the automatic sequence again.


34

Features: -

- Modular Design - flexible lifting capacities and speed of operation.

- Ease of Service - are standard parts available worldwide.

- All movements controlled by inverters - reducing wear on brakes, ropes and mechanical parts.

- Touch-screen - operator can easily select the required program for automatic operations.

- Bucket can be lowered to ground level

- The hoisting-unit has a high safety level; the skip hangs in 4 separate ropes.

- Guiding system that stops the skip hitting the beams

Advantages: -

- The CDS will cut labour costs

- The CDS will increase production capacity

- Skip can be placed on an existing crane track

- No additional crane track for a bullet bucket is necessary

- The system is easy to program

- The system is easy to maintain

- The Skip is easy to clean on floor level

- The CDS doesn't interfere with other machinery on the ground


35

- The CDS can be utilised to lift Production Machinery

- Working with this system will improve the safety in the plant

Specifications: -

The standard electrically operated Automatic Concrete Distribution System is designed according to the

following specifications: -

- Lifting capacity : max. 2m of concrete

- Span : 15m

- Bucket Hoisting speed : 0-10 m per min.

- Crab travelling speed : 0-31.5 m per min.

- Crane travelling speed : 0-100 m per min.

- Lifting height : max. 6.5m

- Skip capacity : 2m of concrete

Optional Extras: -

- An extra hoisting unit can be provided to adapt the system to lift the Extruder & other

production equipment.

- Two extra hoisting units can also be provided to use the crane to lift the hollowcore slabs.

- The crane can be installed with a modem, so that software can be serviced and changed

online.

- If there are two or more cranes on the track an anti-collision system can be installed.

- The system can be equipped with an anti-sway option.

- Depending on the existing facilities a filling station can be provided & installed.

If you have an existing factory and looking at the feasibility of adding the CDS to it then please ensure

you also include the following details: -

- Drawings of the layout of your production plant

- Location of the Batching Plant

- Number of the Casting Beds

- Length of the Casting Beds


36

- Details on existing overhead cranes

- Available Headroom

Curing

The application of heat into the cast slabs initiates and accelerates the curing of the concrete. The

Production Beds can be heated by either hot oil or water pipes running underneath the beds or by steam

curing.

Water is by far the most popular as it is reliable, cost effective, manageable and relatively cheap. Inlet

temperatures of 60 70c should be maintained with enough flow to maintain outlet temperatures at

around 25 35c.

To ensure good early strengths, heat should be applied during the casting operation and at the earliest

opportunity after casting the concrete should be covered with a plastic water retaining cover.

An optional Cover Trolley is available on the Bed Cleaner, which lays & picks-up the covers. This ensures

that the covers are used immediately behind the casting machine and reduce the time to apply and

remove the covers.


37

Temperature monitoring can also be used to either spot check the temperature rise or with more sophisticated

systems to control the application of the heat.

Cutting the Slabs

For reliable and consistent cutting of the slab: -

- Allow a minimum power supply of 40 kilowatts.

- Minimum water pressure of 50 to 60 psi at the saw.

- Water facility to supply up to 36 litres per cut.

- The saw uses diamond tipped blades which can cost from 600 to 900 per blade. The target

cost of blades is around 30 pence per cut but up to 50 pence per cut is acceptable.

- The estimated time for a cut is 1 to 2 minutes. With moving and positioning this gives a

cycle time of 4 to 5 minutes per cut.

- Water can supplied to the saw using a hose Cable Reeler or a water supply provided at

quarter points down the bed.


38

Basic 90o Crosscuts

The Spiroll Crosscut Saw is a basic and robust saw specifically designed for cutting 90 crosscuts along the

hollowcore concrete slabs.

The saw runs on the casting bed rails enabling it to travel over cut-outs in the slab. It can be adjusted relative to

the casting bed ensuring accurate 90 cuts and cutting depths. The hydraulic design allows ease of use and

better operational control. The saw comes complete with two hydraulic Cable Reelers for power & water.

The saw is designed to the following specifications: -

- Length 3.58m

- Width 1.81m

- Height 2.46m

- Weight 2300kgs

- Max Cutting Depth 320mm

- Max Blade Size 900mm

- Blade Motor Power 45kw


39

- Hydraulic Motor Power 9kw

- Reels (Water/Electric) 0.5kw

- Driving Speed 0 - 30 m/min

- Cutting Time (20x120cm Slab) 90 seconds

Basic Long/Rip Cuts


40

Multi-Angle Cuts

The Spiroll Multi-Angle Saw is designed to cut any required angle in the hollow core slab from 0-90. It also has

the capacity to cut long rips at any point along the precast concrete slab.

The saw requires an Operator to control the machine. The Operator has a clear unobstructed view of the hollow

core slabs and directs all movements through a hydraulic control system.


41

The saw a CCTV system so that the Operator can see in front of the electric reels where the view may be

restricted.

Optional extras include Laser Marking to ensure accurate cutting, Angular Measurement Tool, LED Display &

Glass Protection Screen.

Specifications: -

- Length 6.20m

- Width 1.90m

- Height 3.30m

- Weight 6000kgs





- Reels (Water/Electric) 0.5kw




42

Secondary Cutting Station

The Yard Saw provides a secondary cutting facility for long cuts and angle cuts to be carried out on the

hollow core slabs in the stock yard. This additional cutting facility enables a quicker turn around on the

casting beds.

The beds can be stripped quickly and secondary cutting can be carried out without delaying the

production. Yard stock can also be cut to meet other demand

The Spiroll Yard Saw is essentially the same as the Multi-Angle Saw except the Operators Cabin is totally

enclosed and it doesnt have the hydraulic Cable Reelers for the water & electricity.

The Yard Saw has been in production since 1997 and is a tough and reliable saw. Because of its simple

design principles it has a very high productivity rate with minimal downtime.


43

The Yard Saw has the capacity to cut any angle from 0 - 90 degrees. The saw can cut at a rate of 1.5m to

2.0m/min in a slab of 150mm deep and has the capacity to cut long rips at any point on the slab.

The Yard Saw has a cabin for the Operator to work in which will be fitted with an internal light and 110v

plug. It comes complete with a laser and an Angular Measure Device is an optional extra.

The Yard Saw has the following specifications: -

- Length 5.45m

- Width 1.80m

- Height 3.21m

- Weight 5100kgs







Lifting & Transporting the Slabs

Lifting (Stripping) Clamps

The Spiroll Lifting Clamps are utilised to lift the product off the beds either by crane of forklift. They would

then be stacked ready for transfer away from the beds to the Stock Yard.

The Spiroll clamps are heavy duty and have high load ratings. They are designed with pivoting clamp

faces making it possible for the clamp faces to match the cross section regardless of any concrete growth.

Both erect and lifting clamps feature a quick engagement and release design for smooth continuous

workflow.


44

As the production volumes increase, in order to avoid single-piece movement from casting area to storage

the area, lifting equipment should be rated to lift and move to storage at least three to four pieces of

hollowcore.

Transporting Slabs to the Stock Yard

Options for transfer of product are: -

Forklift Truck Front Loader

Forklift Truck Side Loader

Stacker Lifters

Overhead Crane

Direct onto road trailers

Low trailer system

Bogie Trolleys

The production rate will call for movement of: approximately 75 square metres per hour (or approximately

6 to 8 pieces per hour assuming average lengths 8 to 10 metres).

Preparing the Beds

Once the hollowcore slabs have been cut to length & lifted away from the production beds, the beds then

need to be cleaned and oiled. The prestressing strands are then pulled the full length of the bed from the

strand dispensers, threaded through the abutments and the anchors fitted prior to stressing.


45

To assist with these operations and increase productivity, the use of a combined Bed Cleaner, Bed Oiler

and Wire Puller is recommended. The Spiroll Bed Cleaner performs these functions: -

- Cleans the Casting Bed

- Cleans the Bed Rails

- Pushes Debris off the Bed

- Sprays the Bed Oil/Release Agent

- Pulls the Prestressing Wires/Strands

- Lays the Slab Insulation Covers

The Bed Cleaner is powered by a 4 Cylinder Deutz Diesel Engine. The various functions are all

hydraulically controlled by an Operator, who sits within the safety of the protective cabin.

The Bed Cleaner pushes the debris off the beds and it's 3 x rotating brushes clean both the pallet and the

rails.


46

Mould Oil is sprayed on whilst travelling in the reverse direction. A light even coat is applied by the 6 x

Spray Nozzles to the pallet and rails in one pass at 45m/min.

The Bed Cleaner is also designed for simultaneous multi-strand pulling. The hydraulic strand carrier can

pull and deposit up to 10 x 12.5mn prestressing strands at a time. It also lifts and places them over and

beyond the stressing abutments.

This new design incorporates an optional Cover Trolley that is interchangeable and lays polythene covers

onto the hollowcore slabs in order to accelerate the curing time.

Prestressing & Equipment

Strand Dispensers

A floor area should be allowed for 5 or 6 strand dispensers with a configuration, which allows multi-pulling

of the strand, directly from the dispenser, along the bed by a bed cleaner or strand puller. A separate

storage area for strand should be available which is either covered or provision is made to support the

coils off the ground on timber batons and protection provided to prevent rusting.

A guide is normally fitted to the dispenser frame to direct the strand as it is pulled, and to guard against

coils being thrown out and becoming entangled of causing injury.


47

Stressing Equipment

Spiroll is the UKs exclusive supplier of CCL Stressing Equipment. The combined strengths of the two

companies enable Spiroll to provide an unrivalled range of specialist Stressing products combined with a

unique after sales service.

All our Stressing Equipment is BSI Registered, which ensures piece of mind

for both purchasing a quality and reliable build & also for assurance in safety

standards during the stressing operation.

Correct maintenance of the equipment and the training of personnel are

essential to ensure safe stressing.

Particular attention is required to the condition and cleaning of the Stressing Grips. We can provide a full

range of stressing equipment should it be required in the future.


48

Stressing Pump

The SR3000 Pump has been designed specifically for high speed - high volume stressing. The highly

modular design of this prestressing pump facilitates maintenance and servicing while its robust

construction provides excellent protection even in the toughest site conditions.

A push button remote is fitted as standard - allowing the Operator to be positioned safely out of the way

during stressing. The pump is also fully adaptable to different manufacturers jack models.

Optional Extras included a digital trip meter designed to provide up to 4 preset trip loads with the facility

to download and record data for quality control and statistical records.

Stressing Jack

The Stressomatic Jacks can pull from 3mm to 18mm wire/strand and are available and come in Short

Stroke (200mm Extension) & Long Stroke (500mm Extension) variants.

The Jacks come with Power Lock-off as standard. This unique feature allows the internal pulling wedge to

be pushed back against the stressing grip prior to the load being released. This ensures that when the


49

desired amount of prestress is reached there is no load loss and the concrete product will have the correct

amount of prestress.

The jack's high build specification means it is extremely robust and has a longer working life-span. A tool

kit is supplied as standard and includes everything to enable a wedge service to be carried out in a few

minutes.

Stressing Grips

The Open Grip is without doubt the most popular stressing grip. It comprises a wedge in a barrel and its

design enables the wedge position to be checked easily during use and allows unique accessibility during

detensioning.

Advantages of the open grip include: -

Highly economical with few components

Ease of inspection during use

Ease of detensioning


50

Ease of cleaning & maintenance

Spring Loaded Anchors (SLA's)

Spring Loaded Anchors (SLA's) provide correct positioning and are used at the non-stressing end of the

bed. The spring ensures that the wedges sit correctly in the barrel. This prevents them from being

dislodged by work at the prestressing end.

SLA's incorporate the same wedges as the open grip but have larger barrels and a spring mechanism. The

threaded cap anchors can also be joined together with a centre plug to make a double-ended joint.

Digiforce Tension Meter

The Digiforce is a portable, battery-powered Digital Tension Meter that measures the amount of

prestress load (kN) wire & strand.


51

Very quick and easy to use, the Digiforce requires only two pieces of information to be keyed in; the

length of the member between its fixed points and its weight in grams per metre.

The wire or strand is then struck, causing it to resonate whilst the Digiforce is held in close proximity to

sample the frequency, within a few seconds the tension force is displayed on the screen.

It operates on the principle that when a tensioned member anchored between two points is struck it

vibrates at a frequency related to its tensile stress. The Digiforce detects the frequency of vibration

when held in close proximity to the member and computes it into a force value on the digital display.

The Digiforce has a data logger facility enabling test results to be saved and downloaded to a PC via an

RS232 serial port and is supplied in a robust carry case with a mallet, laminated look-up tables for the

weight of wires & strands.


52

Fixing the Slabs

SlabLock Clamps

The SlabLock Clamps are a proven continental lifting and fixing system that has a 100% - 10-year safety

record. Most Clamps depend on gravity and lever action to give the required force to grip the slabs.

Knocking the slab or clamps could upset the grip - which may result in a potentially dangerous situation.

The SlabLock erection clamps have a unique locking device which locks the jaws into any position,

ensuring that your lifting equipment is compliant with current lifting regulations and reducing the risks

associated with lifting and handling product on site.

The Slab Lock is available for various slab types and can be easily adjusted for various configurations.


53

Fall Arrest Clamps

The Fall Arrest Clamp has been developed specifically for the site fixing of hollow core slabs & stairs. The

System is designed around a unique Automatic Safety Clamp that locks onto the hollowcore slab and has

a Quick Release Mechanism for ease of use.

Automatic Clamping Mechanism

Quick Release Lever

Simple to Use

Lightweight

Specific Application for fixing Hollowcore Slabs

Maintenance & Testing Support

Certified and CE approved by Lloyd's

For activities at a height over 2.5 metres a Personal Security Device is compulsory by EC norms if no other

protection is available.

This 'Active' Fall Arrest System is used when the preferred 'Passive' solution is not possible. In particular

when the hollowcore slab & staircases are being placed and the assembly crew is working at the

unguarded edge to receive and fit the elements.

The clamp is spring loaded allowing it to be placed with one hand only and ensuring that it always fits

neatly into the floor profile. If the safety line is loaded in any direction, it will immediately tighten up the

clamp grip and ensure that the clamp will not move from its allocated position.

The larger the load on the safety line, the greater the clamp grips. The clamp safety line is connected to a

certified and type approved harness.


54

Edge Protection

The Edge Protection System that has been designed & developed to provide a temporary barrier for

Operators when fixing hollow core slabs and stairwells on site. This Edge Protection System offers a safe,

& practical solution to provide extra protection for Operators working on leading edges & around

stairwells.

This unique Edge Protection System incorporates an easy to use strapping system. The system has been

designed with a ratchet mechanism that tightens & locks it securely onto the hollowcore slabs. Scaffolding

or Fence Posts are then inserted to form the temporary barrier.

Features: -

Versatile Strapping System

Quick Release Lever


55

Simple to Use

Lightweight

Flexible Application

Fitted prior to lifting/fixing

Certified and CE Approved

It is also possible for the Edge Protection System to be strapped onto the slabs prior to lifting and fixing

into place. This provides additional time-savings on site and also ensures that system is installed safely on

the ground.


56

Hollowcore Production Software Spiroll FloorCAD is a hollowcore design & production software package that is fully integrated with

AutoCAD and WinFloor.

Control of logistics is vital to the success of hollowcore

manufacturing. It requires accurate and consistent control of the

design, production, marking, storage & site delivery. Spiroll

FloorCAD software has been designed and developed to provide

this support. It effectively ensures that the right product is made

at the right time to meet the individual project requirements.

Spiroll FloorCAD software effectively controls the factory. It saves

design office time, planning time, optimise materials & concrete

usage & facilitates identification and loading.

The software provides the opportunity to layout the finished floor, designed to British, American &

European codes, and then translates it as a production plan back to the slab on the casting bed.


57

Spiroll FloorCAD allows you to control the manufacture of hollowcore slabs by the following functions: -

Drawing & Design: -

Create & alter any profile shape & integrate with the AutoCAD layout.

Engineering drawings can be imported or redrawn.

Areas can be swapped until a suitable layout has been achieved.

One click design check on any slab.

Split slabs can inserted if required.

Configures slabs to suit the bearings and layouts.

Checks wire patterns, slab depths and toppings.

Prepares bending moment diagrams, shear force diagrams & calculations.

Calculations can be printed in Excel for design engineers.


58

Production Control: -

Issues production schedules of slabs for each project.

Plans production beds & optimises bed utilisation.

Prints bed production sheets.

Prints sketch cards for marking out & special work details.

Prints sticky labels for individual slab identification.

Storage & Despatch: -

Prepares pick lists for loading.

Monitors loading sequence & weights.

Prevents vehicle overloading.

Controls site fixing progress.

Linked to accountancy package.


59

Additional Features: -

An unlimited number of software licences are permitted.

Annual design & software updates are provided at no additional cost.

Can be linked to a Bed Plotter.

We offer a full 60 day trial of the software with no obligation to buy.

Spiroll FloorCAD is a cost effective package that gives total control from the first engineers drawings to

the final despatch and fixing of the product on site. The software package is rented out for a competitive

annual fee. There is no limit or extra charge on the number of users & upgrades are provide free of

charge.

Please feel free to contact Spiroll should you wish to receive further details or obtain a copy of FloorCAD

for trial purposes.

Documents

Hollowcore Plant Design Manual